File "preparation-purification-of-aspirin--1.html"

Path: /ThinkIB/chem/chemistry/page/19159/preparation-purification-of-aspirin--1html
File size: 106.45 KB
MIME-type: text/html
Charset: utf-8

 
Open Back
<!DOCTYPE html>
<html lang="en">
<head>
	    <!-- Google Tag Manager -->
    <script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':
        new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],
        j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src=
        'https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);
        })(window,document,'script','dataLayer','GTM-K5VSFSN');
    </script>
    <!-- End Google Tag Manager -->
	<meta http-equiv="x-ua-compatible" content="IE=Edge">
	<title>DP Chemistry: Preparation & purification of aspirin </title>
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<meta name="robots" content="index, follow"><meta name="googlebot" content="noarchive">
	<!-- Removed by WebCopy --><!--<base href="https://www.thinkib.net">--><!-- Removed by WebCopy --><meta name="keywords" content="chemistry, inthinking, IB, IBDP, IBMYP, thinkib, baccalaureate, education"><meta name="description" content="The photograph of the packet above is an interesting image as each tablet contains 75 mg of aspirin. When aspirin is taken to relieve the symptoms of pain or fever the tablets usually contain 300 mg of aspirin. The 75 mg tablets are commonly prescribed to be taken once a day by people suffering from hypertension (high blood pressure). Because aspirin has the effect of thinning the blood this helps to reduce the risk..."><meta prefix="og: http://ogp.me/ns#" property="og:title" name="og:title" content="DP Chemistry: Preparation & purification of aspirin">
  <meta prefix="og: http://ogp.me/ns#" property="og:image" content="https://www.thinkib.net/img/tib-icons/standard-level-32.png">
  <meta prefix="og: http://ogp.me/ns#" property="og:description" name="og:description" content="The photograph of the packet above is an interesting image as each tablet contains 75 mg of aspirin. When aspirin is taken to relieve the symptoms of pain or fever the tablets usually contain 300 mg of aspirin. The 75 mg tablets are commonly prescribed to be taken once a day by people suffering from hypertension (high blood pressure). Because aspirin has the effect of thinning the blood this helps to reduce the risk...">
  <meta prefix="og: http://ogp.me/ns#" property="og:url" name="og:url" content="https://www.thinkib.net/chemistry/page/19159/preparation-purification-of-aspirin-">
  <meta prefix="og: http://ogp.me/ns#" property="og:site_name" name="og:site_name" content="Subscription websites for IB teachers & their classes">
  <meta prefix="og: http://ogp.me/ns#" property="og:locale" name="og:locale" content="en">
  <meta prefix="og: http://ogp.me/ns#" property="og:type" name="og:type" content="website">
  <meta name="description" content="The photograph of the packet above is an interesting image as each tablet contains 75 mg of aspirin. When aspirin is taken to relieve the symptoms of pain or fever the tablets usually contain 300 mg of aspirin. The 75 mg tablets are commonly prescribed to be taken once a day by people suffering from hypertension (high blood pressure). Because aspirin has the effect of thinning the blood this helps to reduce the risk...">
  <meta name="image" content="https://www.thinkib.net/img/tib-icons/standard-level-32.png">
  <meta name="keywords" content="Chemistry, Inthinking, IB, IBDP, IBMYP, Thinkib, Baccalaureate, Education, inthinking, thinkib, baccalaureate, education, diploma, international baccalaureate, international schools, high school degree, middle years, middle years programme, international education, IB diploma">
  <meta itemprop="name" content="DP Chemistry: Preparation & purification of aspirin">
  <meta itemprop="description" content="The photograph of the packet above is an interesting image as each tablet contains 75 mg of aspirin. When aspirin is taken to relieve the symptoms of pain or fever the tablets usually contain 300 mg of aspirin. The 75 mg tablets are commonly prescribed to be taken once a day by people suffering from hypertension (high blood pressure). Because aspirin has the effect of thinning the blood this helps to reduce the risk...">
  <meta itemprop="image" content="https://www.thinkib.net/img/tib-icons/standard-level-32.png">
  <meta name="twitter:card" content="summary_large_image">
  <meta name="twitter:title" content="DP Chemistry: Preparation & purification of aspirin">
  <meta name="twitter:description" content="The photograph of the packet above is an interesting image as each tablet contains 75 mg of aspirin. When aspirin is taken to relieve the symptoms of pain or fever the tablets usually contain 300 mg of aspirin. The 75 mg tablets are commonly prescribed to be taken once a day by people suffering from hypertension (high blood pressure). Because aspirin has the effect of thinning the blood this helps to reduce the risk...">
  <meta name="twitter:image" content="https://www.thinkib.net/img/tib-icons/standard-level-32.png">
  <meta name="twitter:creator" content="@InThinker">
	<link href="../../../css/bootstrap.min-1.css" rel="stylesheet" media="screen">
  <link href="../../../css/font-awesome-4.7.0/css/font-awesome.min-1.css" rel="stylesheet">
	<link href="../../../css/top-nav.min-1.css?v=202211301945" rel="stylesheet" media="screen">
	<link href="../../../css/style.min-1.css?v=202212191040" rel="stylesheet" media="screen">
	<link href="../../../css/style-ib.min-1.css?v=202211282000" rel="stylesheet" media="screen">
	<link rel="stylesheet" type="text/css" href="../../../js/jq-fancybox/jquery.fancybox.min-1.css">
	<link href="../../../js/jq-fancybox/jquery.fancybox.min-1.css" type="text/css" rel="stylesheet">
	<script>function inIframe () {try {return window.self !== window.top;} catch (e) {return true;}}if( inIframe() ) { window.location.href = "/mb/embed?mbtest=1&ref=https%3A%2F%2Fwww.thinkib.net%2Fchemistry%2Fpage%2F19159%2Fpreparation-purification-of-aspirin-"; }</script><link rel="stylesheet" href="../../../assets/css/ckeditor5-custom-1.css" type="text/css"><link rel="stylesheet" href="../../../css/snippets.min-1.css?v=202210181500"><link rel="stylesheet" href="../../../css/article.min-1.css?v=202212151220"><link rel="stylesheet" href="../../../css/toplevel-map-1.css"><link rel="stylesheet" href="../../../css/std-access/std-access-tools.min-2.css?v=202204280950"><link href="../../../css/std-access/std-assignments.min-1.css?v=20220127" rel="stylesheet" media="screen"><link href="../../../js/jq-datepicker/datepicker.min-1.css" type="text/css" rel="stylesheet"><link rel="stylesheet" href="../../../css/side-nav.min-1.css?v=20220520"><script src="../../../js/localdates.min-1.js?v=202009290900"></script><script src="../../../js/ifvisible.min-1.js"></script><script>ifvisible.setIdleDuration(300);</script><script>var tibSitename = "chemistry";</script>
    <script>
        const SITE_TAG = "ib"
        const SITE_WEB = "ThinkIB.net"
        const SITE_DOMAIN = "www.thinkib.net"
        const SITE_URI = "https://thinkib.net"
        const SITE_CLIENT_CODE = "TIB000001"
        let imageThinker = "../../../img/header-thinker-ib.svg";
        let imageStudent = "img/header-student-thinkib.svg";
    </script>
<script>var userHash = "IB Docs (2) Team", userTicket = "IB Docs (2) Team";</script><script src="../../../js/user/local-stats.min-1.js?v=202102101800"></script><link rel="apple-touch-icon-precomposed" sizes="57x57" href="../../../img/favicon/thinkib/apple-touch-icon-57x57-1.png"><link rel="apple-touch-icon-precomposed" sizes="114x114" href="../../../img/favicon/thinkib/apple-touch-icon-114x114-1.png"><link rel="apple-touch-icon-precomposed" sizes="72x72" href="../../../img/favicon/thinkib/apple-touch-icon-72x72-1.png"><link rel="apple-touch-icon-precomposed" sizes="144x144" href="../../../img/favicon/thinkib/apple-touch-icon-144x144-1.png"><link rel="apple-touch-icon-precomposed" sizes="60x60" href="../../../img/favicon/thinkib/apple-touch-icon-60x60-1.png"><link rel="apple-touch-icon-precomposed" sizes="120x120" href="../../../img/favicon/thinkib/apple-touch-icon-120x120-1.png"><link rel="apple-touch-icon-precomposed" sizes="76x76" href="../../../img/favicon/thinkib/apple-touch-icon-76x76-1.png"><link rel="apple-touch-icon-precomposed" sizes="152x152" href="../../../img/favicon/thinkib/apple-touch-icon-152x152-1.png"><link rel="icon" type="image/png" href="../../../img/favicon/thinkib/favicon-196x196-1.png" sizes="196x196"><link rel="icon" type="image/png" href="../../../img/favicon/thinkib/favicon-96x96-1.png" sizes="96x96"><link rel="icon" type="image/png" href="../../../img/favicon/thinkib/favicon-32x32-1.png" sizes="32x32"><link rel="icon" type="image/png" href="../../../img/favicon/thinkib/favicon-16x16-1.png" sizes="16x16"><link rel="icon" type="image/png" href="../../../img/favicon/thinkib/favicon-128-1.png" sizes="128x128"><meta name="application-name" content="&nbsp;"><meta name="msapplication-TileColor" content="#FFFFFF"><meta name="msapplication-TileImage" content="https://www.thinkib.net/img/favicon/thinkib/mstile-144x144.png"><meta name="msapplication-square70x70logo" content="https://www.thinkib.net/img/favicon/thinkib/mstile-70x70.png"><meta name="msapplication-square150x150logo" content="https://www.thinkib.net/img/favicon/thinkib/mstile-150x150.png"><meta name="msapplication-wide310x150logo" content="https://www.thinkib.net/img/favicon/thinkib/mstile-310x150.png"><meta name="msapplication-square310x310logo" content="https://www.thinkib.net/img/favicon/thinkib/mstile-310x310.png">
</head>

<body onunload="" class="">
	    <!-- Google Tag Manager (noscript) -->
    <noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-K5VSFSN" height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript>
    <!-- End Google Tag Manager (noscript) -->
    <div id="header">
    <div class="wmap">
        <div class="layout-wrapper">
            <div class="container-fluid">
                <div class="pull-right visible-phone">
                    <a href="https://www.inthinking.net">
                        <img class="header-logo" src="../../../img/header-logo-1.svg" style="height: 45px; width: auto;">
                    </a>
                </div>
                <div class="visible-phone" style="clear:both;"></div>

                <div class="pull-left">
                	<h1><a href="/chemistry"><span style="">IBDP Chemistry brought to you by the IB Docs (2) Team</span></a></h1>
                	<p class="slogan hidden-phone"><span class="slogan"><em>InThinking</em> Subject Sites for teachers &amp; their classes</span></p>
                    <p class="hidden-phone">Website by <strong>Geoffrey Neuss</strong></p>
                    <p class="hidden-phone">Updated 2 JIB Docs (2) Teamary 2023</p>
                </div>
                <div class="visible-phone" style="clear:both;"></div>

                <div class="pull-right text-right header-right">
                    <a class="hidden-phone" href="https://www.inthinking.net">
                        <img class="header-logo" src="../../../img/header-logo-1.svg" style="height: 70px; width: auto;">
                    </a>
                    <div class="search">
                        <a href="#" class="toggle-menu-search" data-toggle="dropdown">
                            <i class="fa fa-2x fa-search"></i>
                        </a>
                    </div>
                </div>
            </div>
        </div>
    </div>
</div>


	<div id="topmenu">
		<div class="layout-wrapper">
			<div>
				<nav class="top-nav"><ul class="level-0"><li class=""><a href="../../../chemistry.html"><i class="fa fa-home"></i> Home</a><ul><li class=""><a href="/subscribe"><i class="fa fa-globe fixwidth"></i> Subscribe today</a></li><li class=""><a href="chemistry/sitemap"><i class="fa fa-sitemap fixwidth"></i> Sitemap</a></li><li class=""><a href="chemistry/last-updates"><i class="fa fa-file-text-o fixwidth"></i> Latest updates</a></li><li class=""><a href="chemistry/teaching-materials"><i class="fa fa-puzzle-piece fixwidth"></i> Teaching materials</a></li><li class=""><a href="chemistry/blog"><i class="fa fa-paperclip fixwidth"></i> Blog</a></li><li class=""><a href="chemistry/twitter"><i class="fa fa-twitter fixwidth"></i> Tweets</a></li><li><a><i class="fa fa-external-link fixwidth"></i> <em>InThinking</em> sites</a><ul><li><a class="text-right" href="https://thinkib.net"><span class="pull-left"> All subjects</span> <em style="opacity: .8;">www.thinkib.net</em></a></li><li><a href="https://www.thinkib.net/biology" target="_blank">IBDP Biology</a></li><li><a href="https://www.thinkib.net/businessmanagement" target="_blank">IBDP Business Management</a></li><li><a href="https://www.thinkib.net/economics" target="_blank">IBDP Economics</a></li><li><a href="https://www.thinkib.net/englishalit" target="_blank">IBDP English A Literature</a></li><li><a href="https://www.thinkib.net/englishalanglit" target="_blank">IBDP English A: Language &amp; Literature</a></li><li><a href="https://www.thinkib.net/englishb" target="_blank">IBDP English B</a></li><li><a href="https://www.thinkib.net/ess" target="_blank">IBDP Environmental Systems &amp; Societies</a></li><li><a href="https://www.thinkib.net/frenchb" target="_blank">IBDP French B</a></li><li><a href="https://www.thinkib.net/geography" target="_blank">IBDP Geography</a></li><li><a href="https://www.thinkib.net/german" target="_blank">IBDP German A: Language &amp; Literature</a></li><li><a href="https://www.thinkib.net/history" target="_blank">IBDP History</a></li><li><a href="https://www.thinkib.net/mathanalysis" target="_blank">IBDP Maths: Analysis &amp; Approaches</a></li><li><a href="https://www.thinkib.net/mathapplications" target="_blank">IBDP Maths: Applications &amp; Interpretation</a></li><li><a href="https://www.thinkib.net/physics" target="_blank">IBDP Physics</a></li><li><a href="https://www.thinkib.net/psychology" target="_blank">IBDP Psychology</a></li><li><a href="https://www.thinkib.net/leadership" target="_blank">IB School Leadership</a></li><li><a href="https://www.thinkib.net/spanisha" target="_blank">IBDP Spanish A</a></li><li><a href="https://www.thinkib.net/spanish-abinitio" target="_blank">IBDP Spanish Ab Initio</a></li><li><a href="https://www.thinkib.net/spanishb" target="_blank">IBDP Spanish B</a></li><li><a href="https://www.thinkib.net/teachmaths" target="_blank">teachMathematics</a></li><li><a href="https://www.thinkib.net/visualarts" target="_blank">IBDP Visual Arts</a></li><li><a href="https://www.thinkib.net/myp-englishalanglit" target="_blank">IBMYP English Language &amp; Literature</a></li><li><a href="https://www.thinkib.net/myp-resources" target="_blank">IBMYP Resources</a></li><li><a href="https://www.thinkib.net/myp-spanishb" target="_blank">IBMYP Spanish Language Acquisition</a></li><li><a href="https://www.thinkib.net/ibcp" target="_blank">IB Career-related Programme</a></li><li><a href="https://www.thinkigcse.net" target="_blank"><strong>ThinkIGCSE</strong> - <em>Subject sites for IGCSE teachers</em></a></li></ul></li></ul><li><li><a href="../16256/start-here-1.html">Start here</a><ul class="level-1"><li><a href="../36257/how-to-navigate-the-site-1.html">How to navigate the site</a></li><li><a href="../24826/using-student-access--1.html" class="father">Using student access </a><ul class="level-2"><li><a href="../27330/creating-student-accounts--1.html">Creating student accounts  </a></li><li><a href="../32806/short-cut-to-give-students-access-to-a-page-1.html">Short cut to give students access to a page</a></li><li><a href="../27328/setting-assignments-1.html">Setting assignments</a></li><li><a href="../27351/managing-student-accounts-mark-book-1.html">Managing student accounts & mark book</a></li><li><a href="../27362/using-qbank-1.html">Using qBank</a></li></ul></li><li><a href="../16257/for-teachers-new-to-ib-chemistry-1.html" class="father">For teachers new to IB Chemistry</a><ul class="level-2"><li><a href="../16258/dart-board-chemistry-1.html">&#039;Dart board&#039; chemistry</a></li><li><a href="../16274/essential-resources-1.html">Essential resources</a></li><li><a href="../16276/syllabus-1.html">Syllabus</a></li><li><a href="../16278/possible-teaching-schedule-1.html">Possible teaching schedule</a></li></ul></li></ul></li><li><a href="../46318/teaching-learning-resources-1.html">Teaching, learning & resources</a><ul class="level-1"><li><a href="../17394/approaches-to-teaching-1.html" class="father">Approaches to teaching</a><ul class="level-2"><li><a href="../17395/teaching-styles--1.html">Teaching styles </a></li><li><a href="../17396/teaching-skills--1.html">Teaching skills </a></li><li><a href="../17398/workshops--1.html">Workshops </a></li><li><a href="../17397/teacher-recommendations--1.html">Teacher recommendations </a></li></ul></li><li><a href="../27280/approaches-to-learning-1.html" class="father">Approaches to learning</a><ul class="level-2"><li><a href="../27208/thinking-skills-1.html">Thinking skills</a></li><li><a href="../27216/reflection-1.html">Reflection</a></li><li><a href="../27209/communication-skills-1.html">Communication skills</a></li><li><a href="../27211/social-skills-1.html">Social skills</a></li><li><a href="../27232/self-management-1.html">Self-management</a></li><li><a href="../27312/research-1.html">Research</a></li></ul></li><li><a href="../17120/resources-1.html" class="father">Resources</a><ul class="level-2"><li><a href="../17119/ib-specific-books-1.html">IB specific books</a></li><li><a href="../17121/general-text-books-1.html">General text books</a></li><li><a href="../17131/post-ib-text-books-1.html">Post IB text books</a></li><li><a href="../17132/journals-1.html">Journals</a></li><li><a href="../17133/newspaper-articles-1.html">Newspaper articles</a></li><li><a href="../17124/demonstrations-1.html">Demonstrations</a></li><li><a href="../17139/chemistry-videos-1.html">Chemistry videos</a></li><li><a href="../17140/web-links-1.html">Web links</a></li><li><a href="../17138/chemistry-apps-1.html">Chemistry apps</a></li><li><a href="../17348/novel-uses-for-the-ib-data-booklet--1.html">Novel uses for the IB data booklet </a></li><li><a href="../17392/books-for-enjoyment--1.html">Books for enjoyment </a></li></ul></li><li><a href="../27313/unit-plans-1.html">Unit plans</a></li><li><a href="../22523/critical-thinking-1.html">Critical thinking</a></li><li><a href="../18044/do-you-speak-ib-1.html" class="father">Do you speak IB?</a><ul class="level-2"><li><a href="../17382/changes-to-terminology-1.html">Changes to terminology</a></li></ul></li><li><a href="../32761/school-closures-and-distance-learning-1.html">School closures and distance learning</a></li></ul></li><li><a href="../16347/core-ahl-1.html">Core & AHL</a><ul class="level-1"><li><a href="../16344/syllabus-1.html">Syllabus</a></li><li><a href="../16329/teaching-each-topic-sub-topic-1.html" class="father">Teaching each topic & sub-topic</a><ul class="level-2"><li><a href="../16328/topic-1-1.html">Topic 1</a></li><li><a href="../16907/topics-2-12--1.html">Topics 2 & 12 </a></li><li><a href="../17021/topics-3-13-1.html">Topics 3 & 13</a></li><li><a href="../17114/topics-4-14-1.html">Topics 4 & 14</a></li><li><a href="../17669/topics-5-15--1.html">Topics 5 & 15 </a></li><li><a href="../17848/topics-6-16-1.html">Topics 6 & 16</a></li><li><a href="../18038/topics-7-17--1.html">Topics 7 & 17 </a></li><li><a href="../18120/topics-8-18--1.html">Topics 8 & 18 </a></li><li><a href="../18350/topics-9-19-1.html">Topics 9 & 19</a></li><li><a href="../18475/topics-10-20--1.html">Topics 10 & 20 </a></li><li><a href="../17285/topics-11-21--1.html">Topics 11 & 21 </a></li></ul></li><li><a href="../16441/the-nature-of-science-1.html" class="father">The Nature of Science</a><ul class="level-2"><li><a href="../16450/key-terms-concepts-1.html">Key terms & concepts</a></li><li><a href="../34566/nos-critical-thinking-1.html">NOS & Critical Thinking</a></li><li><a href="../32100/how-the-elements-were-named-1.html">How the elements were named</a></li><li><a href="../36753/the-culture-of-chemistry-1.html">The Culture of Chemistry</a></li><li><a href="../17333/nature-of-science-questions-1.html">Nature of Science questions</a></li></ul></li><li><a href="../16413/incorporating-im-tok-utilization-etc-1.html" class="father">Incorporating IM, TOK, &#039;Utilization&#039; etc.</a><ul class="level-2"><li><a href="../16414/topic-1-1.html">Topic 1</a></li><li><a href="../16916/topics-2-12-1.html">Topics 2 & 12</a></li><li><a href="../17023/topics-3-13--1.html">Topics 3 & 13  </a></li><li><a href="../17055/topics-4-14--1.html">Topics 4 & 14 </a></li><li><a href="../17270/topics-5-15--1.html">Topics 5 & 15  </a></li><li><a href="../17854/topics-6-16--1.html">Topics 6 & 16 </a></li><li><a href="../18041/topics-7-17--1.html">Topics 7 & 17 </a></li><li><a href="../18099/topics-8-18-1.html">Topics 8 & 18</a></li><li><a href="../18349/topics-9-19--1.html">Topics 9 & 19 </a></li><li><a href="../18420/topics-10-20-1.html">Topics 10 & 20</a></li><li><a href="../17269/topics-11-21--1.html">Topics 11 & 21 </a></li></ul></li><li><a href="../17866/utilization-relationships-between-topics--1.html" class="father">&#039;Utilization&#039; - Relationships between topics </a><ul class="level-2"><li><a href="../17867/relating-topics-4-14-to-all-the-other-topics-1.html">Relating Topics 4 & 14 to all the other topics</a></li><li><a href="../17868/example-of-connections-1.html">Example of connections</a></li><li><a href="../34404/hydroxychloroquine-ib-chemistry-1.html">Hydroxychloroquine & IB Chemistry</a></li><li><a href="../35418/ammonium-nitrate-ib-chemistry-1.html">Ammonium nitrate & IB Chemistry</a></li></ul></li><li><a href="../16685/multiple-choice-tests-for-each-topic-1.html" class="father">Multiple choice tests for each topic</a><ul class="level-2"><li><a href="../16687/sl-questions-by-topic-1.html">SL Questions by topic</a></li><li><a href="../16688/hl-questions-by-topic-1.html">HL Questions by topic</a></li></ul></li></ul></li><li><a href="../19044/options--1.html">Options </a><ul class="level-1"><li><a href="../19503/option-a--1.html" class="father">Option A  </a><ul class="level-2"><li><a href="../19504/introduction-to-materials-science--1.html">Introduction to materials science </a></li><li><a href="../19519/metals-and-icp-spectroscopy-1.html">Metals and ICP spectroscopy</a></li><li><a href="../19541/catalysts--1.html">Catalysts </a></li><li><a href="../19580/liquid-crystals-1.html">Liquid crystals</a></li><li><a href="../19665/polymers--1.html">Polymers  </a></li><li><a href="../19672/nanotechnology-1.html">Nanotechnology</a></li><li><a href="../19843/environmental-impact-plastics-1.html">Environmental impact - plastics</a></li><li><a href="../19858/superconducting-metals-x-ray-crystallography--1.html">Superconducting metals & X-ray crystallography </a></li><li><a href="../19666/condensation-polymers-1.html">Condensation polymers</a></li><li><a href="../19916/environmental-impact-heavy-metals-1.html">Environmental impact - heavy metals</a></li></ul></li><li><a href="../19284/option-b--1.html" class="father">Option B </a><ul class="level-2"><li><a href="../19290/introduction-to-biochemistry--1.html">Introduction to biochemistry  </a></li><li><a href="../19287/proteins-enzymes--1.html">Proteins & enzymes </a></li><li><a href="../19291/lipids-1.html">Lipids</a></li><li><a href="../19299/carbohydrates--1.html">Carbohydrates </a></li><li><a href="../19305/vitamins--1.html">Vitamins   </a></li><li><a href="../19313/biochemistry-the-environment--1.html">Biochemistry & the environment </a></li><li><a href="../19336/proteins-enzymes-ahl--1.html">Proteins & enzymes (AHL)   </a></li><li><a href="../19347/nucleic-acids--1.html">Nucleic acids   </a></li><li><a href="../19361/biological-pigments--1.html">Biological pigments   </a></li><li><a href="../19366/stereochemistry-in-biomolecules-1.html">Stereochemistry in biomolecules</a></li></ul></li><li><a href="../19390/option-c--1.html" class="father">Option C </a><ul class="level-2"><li><a href="../19391/energy-sources-1.html">Energy sources</a></li><li><a href="../19407/fossil-fuels-1.html">Fossil fuels</a></li><li><a href="../19411/nuclear-fusion-nuclear-fission-reactions-1.html">Nuclear fusion & nuclear fission reactions</a></li><li><a href="../19429/solar-energy-1.html">Solar energy</a></li><li><a href="../19437/environmental-impact-global-warming-1.html">Environmental impact - global warming</a></li><li><a href="../19453/electrochemistry-rechargeable-batteries-fuel-cells-1.html">Electrochemistry, rechargeable batteries & fuel cells</a></li><li><a href="../19458/nuclear-fusion-fission-hl--1.html">Nuclear fusion & fission (HL)    </a></li><li><a href="../19470/photovoltaic-cells-and-dsscs-1.html">Photovoltaic cells and DSSCs</a></li></ul></li><li><a href="../19078/option-d-1.html" class="father">Option D</a><ul class="level-2"><li><a href="../19079/pharmaceutical-products-drug-action--1.html">Pharmaceutical products & drug action </a></li><li><a href="../19158/aspirin-penicillin--1.html">Aspirin & penicillin  </a></li><li><a href="../19174/opiates-1.html">Opiates</a></li><li><a href="../19184/ph-regulation-of-the-stomach-1.html">pH regulation of the stomach</a></li><li><a href="../19194/antiviral-medications--1.html">Antiviral medications </a></li><li><a href="../19211/environmental-impact-of-some-medications-1.html">Environmental impact of some medications</a></li><li><a href="../19254/taxol-a-chiral-auxiliary-case-study-1.html">Taxol - a chiral auxiliary case study</a></li><li><a href="../19258/nuclear-medicine--1.html">Nuclear medicine  </a></li><li><a href="../19273/drug-detection-analysis--1.html">Drug detection & analysis </a></li></ul></li></ul></li><li class="selected"><a href="../16592/practical-scheme-of-work-ia--1.html">Practical scheme of work & IA </a><ul class="level-1"><li><a href="../16682/internal-assessment-1.html" class="father">Internal Assessment</a><ul class="level-2"><li><a href="../18892/scaffolding-the-investigation-1.html">&#039;Scaffolding&#039; the investigation</a></li><li><a href="../18896/timing-organisation--1.html">Timing & organisation </a></li><li><a href="../18905/choosing-the-research-question-1.html">Choosing the research question</a></li><li><a href="../18946/personal-engagement-1.html">Personal engagement</a></li><li><a href="../18950/exploration-1.html">Exploration</a></li><li><a href="../18957/analysis-1.html">Analysis</a></li><li><a href="../18965/evaluation-1.html">Evaluation</a></li><li><a href="../18966/communication-1.html">Communication</a></li><li><a href="../19882/internal-standardization-of-the-ia-1.html">Internal standardization of the IA</a></li><li><a href="../19901/submitting-the-samples-for-moderation-2.html">Submitting the samples for moderation</a></li><li><a href="../33754/ten-suggestions-for-ias-using-secondary-data-1.html">Ten suggestions for IAs using secondary data</a></li><li><a href="../37544/gaining-full-marks-for-a-databased-ia--1.html">Gaining full marks for a databased IA </a></li><li><a href="../19506/ia-example-marking-exercise--1.html">IA example & marking exercise </a></li><li><a href="../23929/genuine-examples-of-moderated-ia-reports-1.html">Genuine examples of moderated IA reports</a></li><li><a href="../25234/examples-of-teacher-marked-ia-reports--1.html">Examples of teacher-marked IA reports </a></li><li><a href="../37542/history-of-internal-assessment-1.html">History of Internal Assessment</a></li></ul></li><li><a href="../16598/mandatory-laboratory-components-1.html" class="father">Mandatory laboratory components</a><ul class="level-2"><li><a href="../16613/formula-of-magnesium-oxide--1.html">Formula of magnesium oxide </a></li><li><a href="../16612/determining-the-mr-of-an-unknown-gas-1.html">Determining the <i>M</i><sub>r</sub> of an unknown gas</a></li><li><a href="../16615/acid-base-titrations--1.html">Acid-base titrations </a></li><li><a href="../16616/a-green-acid-base-practical-1.html">A green acid-base practical</a></li><li><a href="../16617/analysis-of-aspirin-tablets-1.html">Analysis of aspirin tablets</a></li><li><a href="../16618/caco3-in-egg-shells-1.html">CaCO<sub>3</sub> in egg shells</a></li><li><a href="../16644/enthalpy-changes-1.html">Enthalpy changes</a></li><li><a href="../16631/reaction-rates-1.html">Reaction rates</a></li><li><a href="../16635/rate-dependent-factors-1.html">Rate-dependent factors</a></li><li><a href="../16636/determining-ea-for-a-reaction-1.html">Determining <i>E</i><sub>a</sub> for a reaction</a></li><li><a href="../16637/iodination-of-propanone-1.html">Iodination of propanone</a></li><li><a href="../18144/titrations-with-a-ph-meter-1.html">Titrations with a pH meter</a></li><li><a href="../18355/redox-titration-with-kmno4--1.html">Redox titration with KMnO<sub>4</sub> </a></li><li><a href="../16640/voltaic-cells-1.html">Voltaic cells</a></li><li><a href="../16659/3-d-molecular-modelling--1.html">3-D molecular modelling </a></li></ul></li><li class="selected"><a href="../17168/other-good-practicals-1.html" class="father">Other good practicals</a><ul class="level-2"><li><a href="../17196/common-chemical-reactions-1.html">Common chemical reactions</a></li><li><a href="../227/elements-oxides-of-the-third-period--1.html">Elements & oxides of the third period </a></li><li><a href="../17239/the-halogens-1.html">The halogens</a></li><li><a href="../17162/boiling-points-of-mixtures-1.html">Boiling points of mixtures</a></li><li><a href="../17170/polarity-of-molecules-1.html">Polarity of molecules</a></li><li><a href="../18083/le-chateliers-principle--1.html">Le Chatelier&#039;s principle </a></li><li><a href="../19582/determining-kc-for-an-esterification-reaction-1.html">Determining <i>K</i><sub>c</sub> for an esterification reaction</a></li><li><a href="../18164/redox-reactions-of-vanadium--1.html">Redox reactions of vanadium </a></li><li><a href="../18351/chlorine-in-swimming-pools--1.html">Chlorine in swimming pools </a></li><li><a href="../18178/analysis-of-cuii-ions-in-solution--1.html">Analysis of Cu(II) ions in solution </a></li><li><a href="../18179/percentage-of-copper-in-brass-1.html">Percentage of copper in brass</a></li><li><a href="../18356/electrolytic-cells--1.html">Electrolytic cells </a></li><li><a href="../18598/reactions-of-organic-compounds-1.html">Reactions of organic compounds</a></li><li><a href="../18752/hydrolysis-of-halogenoalkanes-1.html">Hydrolysis of halogenoalkanes</a></li><li><a href="../18784/preparation-of-13-dinitrobenzene--1.html">Preparation of 1,3-dinitrobenzene </a></li><li><a href="../19022/determination-of-an-organic-structure-1.html">Determination of an organic structure</a></li><li><a href="../19887/preparation-of-nylon-66-1.html">Preparation of nylon 6,6</a></li><li><a href="../19343/determination-of-vitamin-c-content--1.html">Determination of vitamin C content </a></li><li><a href="../19342/hydrolysis-of-starch--1.html">Hydrolysis of starch </a></li><li class="selected"><a href="preparation-purification-of-aspirin--1.html">Preparation & purification of aspirin </a></li></ul></li><li><a href="../18851/ict-in-practical-work-1.html" class="father">ICT in practical work</a><ul class="level-2"><li><a href="../18852/data-logging--1.html">Data logging </a></li><li><a href="../18853/software-for-graph-plotting--1.html">Software for graph plotting </a></li><li><a href="../18854/spreadsheets-for-data-processing--1.html">Spreadsheets for data processing </a></li><li><a href="../18855/databases-1.html">Databases</a></li><li><a href="../18856/computer-modelling-simulations--1.html">Computer modelling & simulations </a></li></ul></li><li><a href="../16594/group-4-project-1.html" class="father">Group 4 Project</a><ul class="level-2"><li><a href="../16595/practicalities-1.html">Practicalities</a></li><li><a href="../16596/reflective-statement--2.html">Reflective statement </a></li></ul></li><li><a href="../16666/a-new-laboratory-1.html">A new laboratory?</a></li></ul></li><li><a href="../16284/exams-1.html">Exams</a><ul class="level-1"><li><a href="../16286/essential-facts-1.html" class="father">Essential Facts</a><ul class="level-2"><li><a href="../16287/objectives-command-terms-1.html">Objectives & command terms</a></li><li><a href="../16288/grade-descriptors-1.html">Grade descriptors</a></li><li><a href="../16289/grade-boundaries-1.html">Grade boundaries</a></li></ul></li><li><a href="../16302/paper-1-multiple-choice-1.html" class="father">Paper 1 (Multiple Choice)</a><ul class="level-2"><li><a href="../16303/advice-to-students-paper-1-1.html">Advice to students (Paper 1)</a></li><li><a href="../31515/practice-paper-1-exams-1.html">Practice Paper 1 exams</a></li></ul></li><li><a href="../16305/paper-2-1.html" class="father">Paper 2</a><ul class="level-2"><li><a href="../16306/advice-to-students-paper-2-1.html">Advice to students (Paper 2)</a></li><li><a href="../16307/areas-of-difficulty-1.html">Areas of difficulty</a></li></ul></li><li><a href="../16313/paper-3--1.html" class="father">Paper 3 </a><ul class="level-2"><li><a href="../16314/advice-to-students-paper-3-1.html">Advice to students (Paper 3)</a></li><li><a href="../16342/data-response-questions-1.html">Data response questions</a></li><li><a href="../20054/experimental-work-questions-1.html">Experimental work questions</a></li></ul></li><li><a href="../16324/the-examination-process-1.html" class="father">The examination process</a><ul class="level-2"><li><a href="../16316/setting-the-exam-papers-1.html">Setting the exam papers</a></li><li><a href="../16317/predicted-grades-1.html">Predicted grades</a></li><li><a href="../16318/marking-the-papers-1.html">Marking the papers</a></li><li><a href="../16319/commenting-on-the-exams-1.html">Commenting on the exams</a></li><li><a href="../16320/grade-awarding-1.html">Grade Awarding</a></li><li><a href="../16321/enquiry-upon-results-1.html">Enquiry upon results</a></li><li><a href="../16322/chief-examiners-report-1.html">Chief Examiner&#039;s report</a></li><li><a href="../16323/retaking-the-exam-1.html">Retaking the exam</a></li></ul></li><li><a href="../16325/faqs-1.html">FAQs</a></li></ul></li><li><a href="../3147/ib-core-1.html">IB Core</a><ul class="level-1"><li><a href="../3149/learner-profile-1.html">Learner Profile</a></li><li><a href="../21735/extended-essays--1.html" class="father">Extended Essays </a><ul class="level-2"><li><a href="../21736/overview--1.html">Overview </a></li><li><a href="../21780/responsibilities-1.html">Responsibilities</a></li><li><a href="../21790/resources-1.html">Resources</a></li><li><a href="../21800/research-1.html">Research</a></li><li><a href="../21804/writing-the-essay-1.html">Writing the essay</a></li><li><a href="../21810/assessment-1.html">Assessment</a></li><li><a href="../22434/summary-of-advice--1.html">Summary of advice </a></li><li><a href="../25272/faqs--1.html">FAQs </a></li></ul></li><li><a href="../307/theory-of-knowledge-tok-1.html" class="father">Theory of Knowledge (TOK)</a><ul class="level-2"><li><a href="../41171/the-12-tok-concepts-1.html">The 12 TOK concepts</a></li><li><a href="../3507/why-tok-chemistry-1.html">Why TOK & Chemistry?</a></li><li><a href="../3505/a-modern-paradigm-1.html">A modern paradigm</a></li></ul></li></ul></li><li><a href="../17783/fast-track-to-tests-questions-1.html">Fast track to tests & questions</a><ul class="level-1"><li><a href="../17784/sl-multiple-choice-tests-on-individual-topics-1.html">SL Multiple choice tests on individual topics</a></li><li><a href="../24351/sl-multiple-choice-quizzes-on-sub-topics-1.html">SL Multiple choice &#039;quizzes&#039; on sub-topics</a></li><li><a href="../31519/sl-practice-paper-1-exams-1.html">SL Practice Paper 1 exams</a></li><li><a href="../17786/sl-questions-on-each-sub-topic-1.html">SL Questions on each sub-topic</a></li><li><a href="../20431/sl-paper-3-section-a-questions-1.html">SL Paper 3 Section A questions</a></li><li><a href="../17792/sl-questions-on-the-options-1.html">SL Questions on the options</a></li><li><a href="../24897/sl-quizzes-on-option-sub-topics--1.html">SL Quizzes on option sub-topics </a></li><li><a href="../17785/hl-multiple-choice-tests-on-individual-topics-1.html">HL Multiple choice tests on individual topics</a></li><li><a href="../24352/hl-multiple-choice-quizzes-on-sub-topics-1.html">HL Multiple choice &#039;quizzes&#039; on sub-topics</a></li><li><a href="../31520/hl-practice-paper-1-exams--1.html">HL Practice Paper 1 exams </a></li><li><a href="../17787/hl-questions-on-each-sub-topic--1.html">HL Questions on each sub-topic </a></li><li><a href="../20428/hl-paper-3-section-a-questions-1.html">HL Paper 3 Section A questions</a></li><li><a href="../17793/hl-questions-on-the-options-1.html">HL Questions on the options</a></li><li><a href="../24973/hl-quizzes-on-option-sub-topics-1.html">HL Quizzes on option sub-topics</a></li><li><a href="../41573/printable-versions-of-written-tasks--1.html">Printable versions of written tasks </a></li></ul></li><li><a href="../41465/complete-course-for-students--2.html">Complete course for students </a><ul class="level-1"><li><a href="../27988/full-coverage-of-each-topic-and-sub-topic-2.html" class="father">Full coverage of each topic and sub-topic</a><ul class="level-2"><li><a href="../27959/topic-1-stoichiometric-relationships-1.html">Topic 1 : Stoichiometric relationships</a></li><li><a href="../27960/topics-2-12-atomic-structure-1.html">Topics 2 & 12 : Atomic structure</a></li><li><a href="../27965/topics-3-13-periodicity-1.html">Topics 3 & 13 : Periodicity</a></li><li><a href="../27971/topics-4-14-chemical-bonding-structure-1.html">Topics 4 & 14 : Chemical bonding & structure</a></li><li><a href="../27987/topics-5-15-energeticsthermochemistry-1.html">Topics 5 & 15 : Energetics/thermochemistry</a></li><li><a href="../27995/topics-6-16-chemical-kinetics-1.html">Topics 6 & 16 : Chemical kinetics</a></li><li><a href="../28001/topics-7-17-equilibrium--1.html">Topics 7 & 17 : Equilibrium </a></li><li><a href="../28017/topics-8-18-acids-and-bases--1.html">Topics 8 & 18 : Acids and bases </a></li><li><a href="../28031/topics-9-19-redox-process-1.html">Topics 9 & 19 : Redox process</a></li><li><a href="../28061/topics-10-20-organic-chemistry-1.html">Topics 10 & 20 : Organic chemistry</a></li><li><a href="../28038/topics-11-21-measurement-data-processing-analysis-1.html">Topics 11 & 21 : Measurement, data processing & analysis</a></li><li><a href="../28074/option-a-materials--1.html">Option A : Materials </a></li><li><a href="../28087/option-b-biochemistry-1.html">Option B : Biochemistry</a></li><li><a href="../28098/option-c-energy--1.html">Option C : Energy </a></li><li><a href="../28109/option-d-medicinal-chemistry-1.html">Option D : Medicinal chemistry</a></li></ul></li><li><a href="../41553/practical-work-including-ia-group-4-project--1.html" class="father">Practical work (including IA & Group 4 Project) </a><ul class="level-2"><li><a href="../41528/internal-assessment-1.html">Internal Assessment</a></li><li><a href="../41657/group-4-project-1.html">Group 4 Project</a></li></ul></li><li><a href="../41387/approaches-to-learning--1.html" class="father">Approaches to learning </a><ul class="level-2"><li><a href="../41380/thinking-skills-1.html">Thinking skills</a></li><li><a href="../41383/communication-skills-1.html">Communication skills</a></li><li><a href="../41384/social-skills--1.html">Social skills </a></li><li><a href="../41385/self-management-skills-1.html">Self-management skills</a></li><li><a href="../41386/research-skills-1.html">Research skills</a></li><li><a href="../41382/reflection-skills--1.html">Reflection skills </a></li></ul></li><li><a href="../41488/the-nature-of-science-1.html" class="father">The Nature of Science</a><ul class="level-2"><li><a href="../41489/key-terms-concepts--1.html">Key terms & concepts </a></li><li><a href="../41492/how-the-elements-were-named--1.html">How the elements were named </a></li><li><a href="../41490/nos-critical-thinking-1.html">NOS & Critical Thinking</a></li><li><a href="../41493/the-culture-of-chemistry--1.html">The Culture of Chemistry </a></li><li><a href="../41494/nature-of-science-questions--1.html">Nature of Science questions </a></li></ul></li><li><a href="../41401/external-assessment-exams-1.html" class="father">External assessment (Exams)</a><ul class="level-2"><li><a href="../41403/essential-facts--1.html">Essential Facts </a></li><li><a href="../41409/paper-1-multiple-choice--1.html">Paper 1 (Multiple Choice) </a></li><li><a href="../41417/paper-2--1.html">Paper 2 </a></li><li><a href="../41431/paper-3--1.html">Paper 3  </a></li></ul></li><li><a href="../41662/extended-essay--1.html" class="father">Extended Essay </a><ul class="level-2"><li><a href="../41685/preparation-1.html">Preparation</a></li><li><a href="../41686/researching--1.html">Researching </a></li><li><a href="../42075/writing-the-essay-1.html">Writing the essay</a></li><li><a href="../41687/assessment-1.html">Assessment</a></li></ul></li></ul></li></ul></nav>
			</div>
		</div>
	</div>

    <nav id="nav-menu-search" style="display: none;">
        <div class="layout-wrapper">
            <form class="form-inline" role="search" method="get" action="chemistry/search">
    <input id="nav-search" name="s" type="search" placeholder="Search Chemistry..." value="">
    <button class="btn btn-sm btn-primary" type="submit">
        Search
    </button>
    <a href="#" class="toggle-menu-search" title="Close">
        <i class="fa fa-lg fa-times gray"></i>
    </a>
</form>

        </div>
    </nav>

	<div class="layout-wrapper">
		<div id="container" class="container-fluid">
			<div id="content">
				<div class="row-fluid">
					<div id="left-column" class="span3"><div class="dropdown" id="userbox"><a class="dropdown-toggle btn" data-toggle="dropdown" onclick="return false;"><img src="../../../img/user/t/IBRR.jpg" style="width: 16px; height: 16px; margin: -2px 0 0 0;">&nbsp;&nbsp;IB Docs (2) Team&nbsp;&nbsp;<i class="fa fa-caret-down gray"></i></a><ul class="dropdown-menu" style="min-width: 200px"><li><a href="https://www.thinkib.net/chemistry" class="" title=""><i class="fa fa-globe fixwidth colored"></i>IBDP Chemistry</a></li><li class="divider"></li><li><a href="https://www.thinkib.net/chemistry/user" class="" title="Check &amp; modify your profile"><i class="fa fa-user fixwidth colored"></i>My profile</a></li><li><a href="https://www.thinkib.net/chemistry/sitemap" class="" title="Get an overview of the site"><i class="fa fa-sitemap colored fixwidth colored"></i>Sitemap</a></li><li><a href="chemistry/std-access" class="" title="Set up/Manage student access"><i class="fa fa-group fixwidth colored"></i>Student access</a></li><li><a href="https://www.thinkib.net/chemistry/user/teacher-accounts" class="" title="Manage teacher accounts"><i class="fa fa-cogs fixwidth colored"></i>Teacher accounts</a></li><li><a href="https://www.thinkib.net/chemistry/user/bookmarks" class="" title="Manage your bookmarked pages"><i class="fa fa-star fixwidth colored"></i>My favorites</a></li><li><a href="https://www.thinkib.net/chemistry/user/messages" class="" title="Read your messages"><i class="fa fa-envelope-o fixwidth colored"></i>Messages</a></li><li><a href="/help/thinkib" class="pop-up-help" title="Help"><i class="fa fa-info-circle fixwidth colored"></i>Help</a></li><li><a href="https://www.thinkib.net/subscribe/" class="" title="Add / Renew subjects"><i class="fa fa-refresh fixwidth colored"></i>Renew</a></li><li class="divider"></li><li><a href="chemistry?logout=1"><i class="fa fa-power-off fixwidth colored"></i>Log out</a></li></ul></div><div id="std-side-box" class="side-box shadow-md" data-pid="19159">
    <div id="std-access-tools" data-pid="19159" data-general-id="3">
        <div class="row-fluid accordion-group">
            <div class="std-access-tools-header">
                <a class="accordion-toggle" data-toggle="collapse" data-parent="#std-access-tools" href="#std-access-tools-content" onclick="return false;">
                    <i class="fa fa-caret-right white"></i>
                    Student access tools
                </a>
                
            </div>
            <div id="std-access-tools-content" class="accordion-body collapse">
                <div class="accordion-inner">
                    <p><i class="fa fa-spin fa-circle-o-notch"></i> Loading...</p>
                </div>
            </div>
        </div>
    </div>
</div>
<nav id="sidemenu" class="side-nav"><div class="header"><span style="color: #fff;"><a href="../16592/practical-scheme-of-work-ia--1.html">Practical scheme of work & IA </a></span><span id="sidetreecontrol"><a title="Collapse all" rel="collapse" href="#"><i class="fa fa-minus-circle"></i></a>&nbsp;<a title="Expand all" rel="expand" href="#"><i class="fa fa-plus-circle"></i></a></span></div><ul class="level-0 always-expanded"><li class=" parent" style="padding-left: 0px"><i class="expander fa fa-caret-right "></i><a href="../16682/internal-assessment-1.html" title="Internal Assessment">Internal Assessment</a></li><ul class="level-1 "><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18892/scaffolding-the-investigation-1.html" title="&#039;Scaffolding&#039; the investigation">&#039;Scaffolding&#039; the investigation</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18896/timing-organisation--1.html" title="Timing & organisation ">Timing & organisation </a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18905/choosing-the-research-question-1.html" title="Choosing the research question">Choosing the research question</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18946/personal-engagement-1.html" title="Personal engagement">Personal engagement</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18950/exploration-1.html" title="Exploration">Exploration</a></li><li class=" parent" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18957/analysis-1.html" title="Analysis">Analysis</a></li><ul class="level-2 "><li class="" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../18958/significant-figures--1.html" title="Significant figures ">Significant figures </a></li><li class="" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../18959/error-uncertainty--1.html" title="Error & uncertainty ">Error & uncertainty </a></li></ul><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18965/evaluation-1.html" title="Evaluation">Evaluation</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18966/communication-1.html" title="Communication">Communication</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../19882/internal-standardization-of-the-ia-1.html" title="Internal standardization of the IA">Internal standardization of the IA</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../19901/submitting-the-samples-for-moderation-2.html" title="Submitting the samples for moderation">Submitting the samples for moderation</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../33754/ten-suggestions-for-ias-using-secondary-data-1.html" title="Ten suggestions for IAs using secondary data">Ten suggestions for IAs using secondary data</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../37544/gaining-full-marks-for-a-databased-ia--1.html" title="Gaining full marks for a databased IA ">Gaining full marks for a databased IA </a></li><li class=" parent" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../19506/ia-example-marking-exercise--1.html" title="IA example & marking exercise ">IA example & marking exercise </a></li><ul class="level-2 "><li class="" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../19741/results-analysis-of-marking-exercise-1.html" title="Results & analysis of marking exercise">Results & analysis of marking exercise</a></li></ul><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../23929/genuine-examples-of-moderated-ia-reports-1.html" title="Genuine examples of moderated IA reports">Genuine examples of moderated IA reports</a></li><li class=" parent" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../25234/examples-of-teacher-marked-ia-reports--1.html" title="Examples of teacher-marked IA reports ">Examples of teacher-marked IA reports </a></li><ul class="level-2 "><li class="" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../44903/marked-ia-reports-with-teacher-comments-marks-1.html" title="Marked IA reports with teacher comments & marks">Marked IA reports with teacher comments & marks</a></li></ul><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../37542/history-of-internal-assessment-1.html" title="History of Internal Assessment">History of Internal Assessment</a></li></ul><li class=" parent" style="padding-left: 0px"><i class="expander fa fa-caret-right "></i><a href="../16598/mandatory-laboratory-components-1.html" title="Mandatory laboratory components">Mandatory laboratory components</a></li><ul class="level-1 "><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../16613/formula-of-magnesium-oxide--1.html" title="Formula of magnesium oxide ">Formula of magnesium oxide </a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../16612/determining-the-mr-of-an-unknown-gas-1.html" title="Determining the Mr of an unknown gas">Determining the <i>M</i><sub>r</sub> of an unknown gas</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../16615/acid-base-titrations--1.html" title="Acid-base titrations ">Acid-base titrations </a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../16616/a-green-acid-base-practical-1.html" title="A green acid-base practical">A green acid-base practical</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../16617/analysis-of-aspirin-tablets-1.html" title="Analysis of aspirin tablets">Analysis of aspirin tablets</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../16618/caco3-in-egg-shells-1.html" title="CaCO3 in egg shells">CaCO<sub>3</sub> in egg shells</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../16644/enthalpy-changes-1.html" title="Enthalpy changes">Enthalpy changes</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../16631/reaction-rates-1.html" title="Reaction rates">Reaction rates</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../16635/rate-dependent-factors-1.html" title="Rate-dependent factors">Rate-dependent factors</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../16636/determining-ea-for-a-reaction-1.html" title="Determining Ea for a reaction">Determining <i>E</i><sub>a</sub> for a reaction</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../16637/iodination-of-propanone-1.html" title="Iodination of propanone">Iodination of propanone</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18144/titrations-with-a-ph-meter-1.html" title="Titrations with a pH meter">Titrations with a pH meter</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18355/redox-titration-with-kmno4--1.html" title="Redox titration with KMnO4 ">Redox titration with KMnO<sub>4</sub> </a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../16640/voltaic-cells-1.html" title="Voltaic cells">Voltaic cells</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../16659/3-d-molecular-modelling--1.html" title="3-D molecular modelling ">3-D molecular modelling </a></li></ul><li class="ancestor parent" style="padding-left: 0px"><i class="expander fa fa-caret-right fa-rotate-90"></i><a href="../17168/other-good-practicals-1.html" title="Other good practicals">Other good practicals</a></li><ul class="level-1 expanded"><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../17196/common-chemical-reactions-1.html" title="Common chemical reactions">Common chemical reactions</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../227/elements-oxides-of-the-third-period--1.html" title="Elements & oxides of the third period ">Elements & oxides of the third period </a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../17239/the-halogens-1.html" title="The halogens">The halogens</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../17162/boiling-points-of-mixtures-1.html" title="Boiling points of mixtures">Boiling points of mixtures</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../17170/polarity-of-molecules-1.html" title="Polarity of molecules">Polarity of molecules</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18083/le-chateliers-principle--1.html" title="Le Chatelier&#039;s principle ">Le Chatelier&#039;s principle </a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../19582/determining-kc-for-an-esterification-reaction-1.html" title="Determining Kc for an esterification reaction">Determining <i>K</i><sub>c</sub> for an esterification reaction</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18164/redox-reactions-of-vanadium--1.html" title="Redox reactions of vanadium ">Redox reactions of vanadium </a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18351/chlorine-in-swimming-pools--1.html" title="Chlorine in swimming pools ">Chlorine in swimming pools </a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18178/analysis-of-cuii-ions-in-solution--1.html" title="Analysis of Cu(II) ions in solution ">Analysis of Cu(II) ions in solution </a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18179/percentage-of-copper-in-brass-1.html" title="Percentage of copper in brass">Percentage of copper in brass</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18356/electrolytic-cells--1.html" title="Electrolytic cells ">Electrolytic cells </a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18598/reactions-of-organic-compounds-1.html" title="Reactions of organic compounds">Reactions of organic compounds</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18752/hydrolysis-of-halogenoalkanes-1.html" title="Hydrolysis of halogenoalkanes">Hydrolysis of halogenoalkanes</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18784/preparation-of-13-dinitrobenzene--1.html" title="Preparation of 1,3-dinitrobenzene ">Preparation of 1,3-dinitrobenzene </a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../19022/determination-of-an-organic-structure-1.html" title="Determination of an organic structure">Determination of an organic structure</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../19887/preparation-of-nylon-66-1.html" title="Preparation of nylon 6,6">Preparation of nylon 6,6</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../19343/determination-of-vitamin-c-content--1.html" title="Determination of vitamin C content ">Determination of vitamin C content </a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../19342/hydrolysis-of-starch--1.html" title="Hydrolysis of starch ">Hydrolysis of starch </a></li><li class="current" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="preparation-purification-of-aspirin--1.html" title="Preparation & purification of aspirin ">Preparation & purification of aspirin </a></li></ul><li class=" parent" style="padding-left: 0px"><i class="expander fa fa-caret-right "></i><a href="../18851/ict-in-practical-work-1.html" title="ICT in practical work">ICT in practical work</a></li><ul class="level-1 "><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18852/data-logging--1.html" title="Data logging ">Data logging </a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18853/software-for-graph-plotting--1.html" title="Software for graph plotting ">Software for graph plotting </a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18854/spreadsheets-for-data-processing--1.html" title="Spreadsheets for data processing ">Spreadsheets for data processing </a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18855/databases-1.html" title="Databases">Databases</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18856/computer-modelling-simulations--1.html" title="Computer modelling & simulations ">Computer modelling & simulations </a></li></ul><li class=" parent" style="padding-left: 0px"><i class="expander fa fa-caret-right "></i><a href="../16594/group-4-project-1.html" title="Group 4 Project">Group 4 Project</a></li><ul class="level-1 "><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../16595/practicalities-1.html" title="Practicalities">Practicalities</a></li><li class="" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../16596/reflective-statement--2.html" title="Reflective statement ">Reflective statement </a></li></ul><li class="" style="padding-left: 0px"><i class="expander fa fa-caret-right "></i><a href="../16666/a-new-laboratory-1.html" title="A new laboratory?">A new laboratory?</a></li></ul></nav></div><!-- /#left-column-->
					<div id="main-column" class="span9"><article id="main-article"><a id="exit-fs" title="Exit presentation mode" href="#" onclick="return false;"><i class="fa fa-arrows-alt"></i></a><ul class="page-actions no-print stacked nav nav-list visible-desktop"><li><a class="presentation" href="#" onclick="return false;"><i class="fa fa-desktop"></i><span>Presentation mode</span></a></li><li><a class="print-section-blog" href="#" onclick="return false;"><i class="fa fa-print"></i><span>Print this page</span></a></li><li><a class="page-bookmarker stacked" data-ticket="IB Docs (2) Team" data-pid="19159" href="#" onclick="return false;"><i class="fa fa-star"></i><span>Favourite</span></a><textarea data-ticket="IB Docs (2) Team" data-pid="19159" id="editor" class="favcomms hidden" placeholder="Your personal notes..."></textarea></li><li><a class="personal-notes" href="#" onclick="return false;"><i class="fa fa-file-text"></i><span>Personal notes</span></a></li><li><a class="" data-toggle="modal" href="#modal-feedback" onclick="return false;"><i class="fa fa-envelope-o"></i><span>Feedback</span></a></li><li class="dropdown"><a class="dropdown-toggle" data-toggle="dropdown" data-target="#" href="#"><i class="fa fa-share-alt"></i><span>Share this page</span></a><ul class="dropdown-menu" role="menu"><li><a class="" target="_blank" title="Share on Twitter" href="https://twitter.com/share?text=%22Preparation+%26+purification+of+aspirin+%22+-+via+%40InThinker+%23chemistry%0A&url=https%3A%2F%2Fwww.thinkib.net%2Fchemistry%2Fpage%2F19159%2Fpreparation-purification-of-aspirin-"><i class="fa fa-twitter-square"></i><span>Twitter</span></a></li><li><a class="" target="_blank" title="Share on Facebook" href="https://www.facebook.com/sharer.php?u=https%3A%2F%2Fwww.thinkib.net%2Fchemistry%2Fpage%2F19159%2Fpreparation-purification-of-aspirin-&t=Preparation+&+purification+of+aspirin+"><i class="fa fa-facebook-square"></i><span>Facebook</span></a></li><li><a class="" href="http://www.linkedin.com/shareArticle?mini=true&url=https%3A%2F%2Fwww.thinkib.net%2Fchemistry%2Fpage%2F19159%2Fpreparation-purification-of-aspirin-"><i class="fa fa-linkedin-square"></i><span>LinkedIn</span></a></li><li><a class="" href="https://plus.google.com/share?url=https%3A%2F%2Fwww.thinkib.net%2Fchemistry%2Fpage%2F19159%2Fpreparation-purification-of-aspirin-"><i class="fa fa-google-plus-square"></i><span>Google +</span></a></li><li><a class="" href="mailto:?subject=Preparation & purification of aspirin &body=The photograph of the packet above is an interesting image as each tablet contains 75 mg of aspirin. When aspirin is taken to relieve the symptoms of pain or fever the tablets usually contain 300 mg of aspirin. The 75 mg...%0Ahttps%3A%2F%2Fwww.thinkib.net%2Fchemistry%2Fpage%2F19159%2Fpreparation-purification-of-aspirin-"><i class="fa fa-envelope"></i><span>Email</span></a></li></ul></li><li><a class="" href="chemistry/teaching-materials"><i class="fa fa-puzzle-piece colored"></i><span>Teaching materials</span></a></li></ul><div class="page-actions no-print navbar inline hidden-desktop"><div class="navbar-inner"><ul class="nav"><li><a class="presentation" href="#" onclick="return false;"><i class="fa fa-desktop"></i></a></li><li><a class="print-section-blog" href="#" onclick="return false;"><i class="fa fa-print"></i></a></li><li><a class="page-bookmarker" data-ticket="IB Docs (2) Team" data-pid="19159" href="#" onclick="return false;"><i class="fa fa-star"></i></a></li><li><a class="personal-notes" href="#" onclick="return false;"><i class="fa fa-file-text"></i></a></li><li><a class="" data-toggle="modal" href="#modal-feedback" onclick="return false;"><i class="fa fa-envelope-o"></i></a></li><li class="dropdown"><a class="dropdown-toggle" data-toggle="dropdown" data-target="#" href="#"><i class="fa fa-share-alt"></i></a><ul class="dropdown-menu" role="menu"><li><a class="" target="_blank" title="Share on Twitter" href="https://twitter.com/share?text=%22Preparation+%26+purification+of+aspirin+%22+-+via+%40InThinker+%23chemistry%0A&url=https%3A%2F%2Fwww.thinkib.net%2Fchemistry%2Fpage%2F19159%2Fpreparation-purification-of-aspirin-"><i class="fa fa-twitter-square"></i><span>Twitter</span></a></li><li><a class="" target="_blank" title="Share on Facebook" href="https://www.facebook.com/sharer.php?u=https%3A%2F%2Fwww.thinkib.net%2Fchemistry%2Fpage%2F19159%2Fpreparation-purification-of-aspirin-&t=Preparation+&+purification+of+aspirin+"><i class="fa fa-facebook-square"></i><span>Facebook</span></a></li><li><a class="" href="http://www.linkedin.com/shareArticle?mini=true&url=https%3A%2F%2Fwww.thinkib.net%2Fchemistry%2Fpage%2F19159%2Fpreparation-purification-of-aspirin-"><i class="fa fa-linkedin-square"></i><span>LinkedIn</span></a></li><li><a class="" href="https://plus.google.com/share?url=https%3A%2F%2Fwww.thinkib.net%2Fchemistry%2Fpage%2F19159%2Fpreparation-purification-of-aspirin-"><i class="fa fa-google-plus-square"></i><span>Google +</span></a></li><li><a class="" href="mailto:?subject=Preparation & purification of aspirin &body=The photograph of the packet above is an interesting image as each tablet contains 75 mg of aspirin. When aspirin is taken to relieve the symptoms of pain or fever the tablets usually contain 300 mg of aspirin. The 75 mg...%0Ahttps%3A%2F%2Fwww.thinkib.net%2Fchemistry%2Fpage%2F19159%2Fpreparation-purification-of-aspirin-"><i class="fa fa-envelope"></i><span>Email</span></a></li></ul></li><li><a class="" href="chemistry/teaching-materials"><i class="fa fa-puzzle-piece colored"></i></a></li></ul></div></div><h1 class="section-title">Preparation & purification of aspirin </h1><ul class="breadcrumb"><li><a title="Home" href="https://www.thinkib.net/chemistry"><i class="fa fa-home"></i></a><span class="divider"><i class="fa fa-chevron-right"></i></span></li><li><a title="Go to: Practical scheme of work & IA " href="../16592/practical-scheme-of-work-ia--1.html">Practical scheme of work & IA </a><span class="divider"><i class="fa fa-chevron-right"></i></span></li><li><a title="Go to: Other good practicals" href="../17168/other-good-practicals-1.html">Other good practicals</a><span class="divider"><i class="fa fa-chevron-right"></i></span></li><li><span>Preparation & purification of aspirin </span></li></ul><div id="std-sidebox-task-added-msg"></div><div id="modal-feedback" class="modal hide fade text-left" tabindex="-1" role="dialog" aria-labelledby="log-in form" aria-hidden="true">
	<div class="modal-header">
		<button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
		<h3>Preparation & purification of aspirin : Feedback</h3>
	</div>
	<div class="modal-body">
		
		<form method="post" id="feedback-form">
			<div class="row-fluid">
				<div class="span12" style="margin: 12px 0">
					<p>
						Which of the following best describes your feedback?
					</p>
					<label class="radio" style="float: left; margin-right: 12px">
						<input type="radio" checked="checked" value="useful" name="feedback-type">
						Recommend
					</label><label class="radio" style="float: left; margin-right: 12px">
						<input type="radio" value="error" name="feedback-type">
						Report a problem
					</label><label class="radio" style="float: left; margin-right: 12px">
						<input type="radio" value="improve" name="feedback-type">
						Suggest an improvement
					</label><label class="radio" style="float: left; margin-right: 12px">
						<input type="radio" value="other" name="feedback-type">
						Other
					</label>
				</div>
				
			</div>
			<div class="row-fluid">
				<label>Comments:</label>
				<div class="row-fluid">
					<textarea class="span12" name="feedback-comment" placeholder="Your feedback... (optional)"></textarea>
				</div>
			</div>
			
			<input type="hidden" name="feedback-submited" value="1">
		</form>
	</div>
	<div class="modal-footer">
		<button class="btn btn-large" type="button" data-dismiss="modal" aria-hidden="true">
			<i class="fa fa-remove"></i>
			Cancel
		</button>
		<button class="btn pull-right" id="submit-feedback" onclick="javascript:$('#feedback-form').submit();return false;">
			<i class="fa fa-check"></i>
			Submit
		</button>
	</div>
</div><section id="main-content"><div class="blueBg"><h1><img alt="" height="22" src="../../../img/tib-icons/standard-level-32-1.png" title="" width="22"> <img alt="" height="22" src="../../../img/tib-icons/higher-level-32-1.png" title="" width="22"> Introduction</h1><p style="text-align: center;"><img alt="" class="noborder" src="../../../ib/chemistry/images/Practicals/aspirin%2075mg.jpg" style="width: 296px; height: 235px;"></p><hr class="hidden"><p>The photograph of the packet above is an interesting image as each tablet contains 75 mg of aspirin. When aspirin is taken to relieve the symptoms of pain or fever the tablets usually contain 300 mg of aspirin. The 75 mg tablets are commonly prescribed to be taken once a day by people suffering from hypertension (high blood pressure). Because aspirin has the effect of thinning the blood this helps to reduce the risk of stroke or heart attack. This point is specifically mentioned in &#39;Understandings&#39; listed in <a href="../19158/aspirin-penicillin--1.html" title="New 2014 programme (First exams 2016) » Options » Option D » Aspirin &amp; penicillin ">D.2 Aspirin &amp; penicillin</a> in Option D: Medicinal chemistry.</p><hr class="hidden"></div><hr class="hidden"><div class="greenBg"><h1>Teacher&#39;s notes&nbsp;</h1><p>This experiment is a good way to cover both some practical skills and the theory of aspirin synthesis that forms part of sub-topic <a href="../19158/aspirin-penicillin--1.html" title="New 2014 programme (First exams 2016) » Options » Option D » Aspirin &amp; penicillin ">D.2 Aspirin &amp; penicillin</a> in Option D: Medicinal chemistry. Students enjoy making a drug that is on the syllabus (and legal to make in a school laboratory!). It could also be given to students who are not studying Medicinal chemistry as an option because it is a good example of <span data-scayt-word="recrystallisation" data-wsc-lang="en_US">recrystallisation</span> and the use of melting point as a way of testing the purity of a product.</p><p>Students should be familiar with <span data-scayt-word="esterification" data-wsc-lang="en_US">esterification</span> by reacting alcohols with carboxylic acids as this is covered in sub-topic <a href="../18741/alcohols--1.html">10.2: Functional group chemistry.</a> However -<span data-scayt-word="OCOR" data-wsc-lang="en_US">OCOR</span> is a better leaving group than -OH and consequently acid anhydrides are much more reactive with <span data-scayt-word="nucleophiles" data-wsc-lang="en_US">nucleophiles</span> than carboxylic acids. For those studying Medicinal chemistry you can relate this to the <span data-scayt-word="diesterification" data-wsc-lang="en_US">diesterification</span> reaction that must occur in order to convert morphine, a strong analgesic, into heroin which is an even stronger analgesic. Morphine is an alcohol and it is more efficient to react one mole of morphine with two moles of <span data-scayt-word="ethanoic" data-wsc-lang="en_US">ethanoic</span> anhydride than with two moles of <span data-scayt-word="ethanoic" data-wsc-lang="en_US">ethanoic</span> acid in order to convert it into heroin.</p><p>If students have already done the experiment to <a href="../16617/analysis-of-aspirin-tablets-1.html" title="New 2014 programme (First exams 2016) » Practical scheme of work » Mandatory laboratory components » Analysis of aspirin tablets">Analyse aspirin tablets</a> then they may also like to <span data-scayt-word="analyse" data-wsc-lang="en_US">analyse</span> the aspirin they prepare in this experiment to show how pure their product is. They can also determine the melting point of their product to determine its purity<sup>1</sup><sup>,2</sup>. Alternatively, or in addition, they could perform thin layer chromatography and develop the chromatogram in iodine (or under a UV lamp) to show whether there is just one component in their product or whether another component such as <span data-scayt-word="unreacted" data-wsc-lang="en_US">unreacted</span> <span data-scayt-word="2-hydroxybenzoic" data-wsc-lang="en_US">2-hydroxybenzoic</span> acid) also shows up. The syllabus mentions the use of infrared spectroscopy and I have provided a question on this at the end of the practical sheet.</p><p>Although it is a rather straightforward practical there is much good chemistry in this experiment. There are no real hazards although of course care will be needed when handling concentrated sulfuric acid and the <span data-scayt-word="ethanoic" data-wsc-lang="en_US">ethanoic</span> acid and <span data-scayt-word="ethanoic" data-wsc-lang="en_US">ethanoic</span> anhydride. The only thing to warn students is that sometimes the reaction goes quite fast and the reaction vessel can get very hot. There is a rather bad video showing you how reactive this can get. Note the safety glasses on the bench and the girl who is not wearing any eye protection.</p><hr class="hidden"><p style="text-align: center;"><iframe allowfullscreen="" frameborder="0" height="280" src="//www.youtube.com/embed/Popgk9qaQss?rel=0" width="360"></iframe></p><p style="text-align: center;"><a href="http://www.youtube.com/watch?v=Popgk9qaQss&feature=player_embedded">Explosion during aspirin preparation <img src="../../../img/icons/video-1.png"><span class="anchor" id="video-1" name="video-1">&nbsp;</span></a></p><hr class="hidden"><h4>Footnotes</h4><p><sup>1</sup> <em>Actually the melting point of aspirin is quite a nice example of the Nature of Science. You would think that the value would be clearly stated in data books and yet there is considerable disagreement. The value often quoted is 134-136 <sup>o</sup>C with decomposition. Some sources however quote <a href="http://uk.vwr.com/store/catalog/product.jsp?product_id=2364168">138-140 <sup>o</sup>C</a> whereas others give exactly <a href="http://en.wikipedia.org/wiki/Aspirin">135 <sup>o</sup>C</a>.</em></p><p><em><sup>2</sup> The Royal Society of Chemistry has produced a <a href="http://www.rsc.org/learn-chemistry/content/filerepository/CMP/00/000/045/Aspirin.pdf">really good resource</a> for both teachers and students on the synthesis of aspirin which also includes how to test for its purity. </em></p><hr class="hidden"></div><hr class="hidden"><div class="box"><h2><img alt="Standard Level" class="ico" height="16" src="../../../img/icons/standard-1.png" title="Standard Level" width="16"> <img alt="Higher Level" class="ico" src="../../../img/icons/higher-1.png" title="Higher Level"> Student worksheet</h2><hr class="hidden"><p style="text-align: center;"><strong>PREPARATION</strong><strong> AND PURIFICATION OF ASPIRIN</strong></p><hr class="hidden"><p>The aim of this experiment is to synthesise a pure sample of aspirin and test the product to see how pure it is. The preparation is relatively simple but through the practical you will use the techniques of recrystallisation and the use of the melting point apparatus. The synthesis is basically esterification but instead of reacting a carboxylic acid with the phenol (alcohol) group of the 2-hydroxybenzoic acid an acid anhydride is used in its place. Note that on the syllabus the IB uses the common name &#39;salicylic acid&#39; for 2-hydroxybenzoic acid.</p><p>The equation for the reaction is:</p><p style="text-align: center; "><img alt="" class="noborder" height="156" src="../../../ib/chemistry/images/Practicals/prep of apsirin equation.jpg" title="Equation for the preparation of aspirin" width="500"></p><hr class="hidden"><p><strong>ENVIRONMENTAL CARE</strong>:</p><p>The organic chemicals used are quickly broken down in the environment and therefore present no threat.</p><hr class="hidden"><p><strong>SAFETY</strong>:</p><p>Ethanoic anhydride, &#39;glacial&#39; ethanoic acid and concentrated sulfuric acid are all corrosive. Treat them with care and wear an apron and safety goggles throughout the experiment.</p><hr class="hidden"><p><strong>PROCEDURE</strong>:</p><p>Shake together 2.0 g of 2-hydroxybenzoic acid (salicylic acid) with 4 cm<sup>3</sup> of ethanoic anhydride in a 100 cm<sup>3</sup> conical flask. Now add 5 drops of concentrated sulfuric acid and continue agitating the flask. It may become quite warm for a while. Crystals of aspirin will appear and soon the mixture will form into a crystalline mass. Now add 4 cm<sup>3</sup> of cold &#39;glacial&#39; ethanoic acid, and cool the flask in a beaker containing a mixture of crushed ice and water. Filter off the aspirin crystals onto a small filter, and wash once with ice water in order to remove residual acid. Recrystallise the aspirin, by dissolving the crystals in a small quantity of hot water, and allow to cool. A mass of very pure aspirin crystals should form. Filter them again, and leave overnight on a watch glass to dry completely.</p><p>Weigh the mass of pure dry aspirin and calculate the yield as a percentage of the theoretical maximum value. This may well be considerably below 100% because you have carried out a recrystallisation, and have worked on a very small scale. Both lead to significant losses of material. In addition, many organic reactions either do not go to completion, or produce by-products. Using the melting point apparatus determine the melting point of your sample and compare it with the data book value. If you have time you can further test the purity of your sample by a titration as described in another practical - <a href="../16617/analysis-of-aspirin-tablets-1.html" title="New 2014 programme (First exams 2016) » Practical scheme of work » Mandatory laboratory components » Analysis of aspirin tablets">Analysis of aspirin tablets</a>.</p><hr class="hidden"><p><strong>QUESTIONS</strong>:</p><p><strong>1. </strong>Methyl salicylate is a different ester that can also be prepared from 2-hydroxybenzoic acid. Discuss how this could be prepared and deduce the equation for the reaction.</p><p><strong>2. </strong>The infrared spectrum of pure aspirin is shown below: (Taken from <a href="http://global.oup.com/education/product/9780198393535/?region=uk">G.Neuss, <em>Oxford IB Chemistry Study Guide</em>, 2014, OUP</a>)</p><p style="text-align: center;"><img alt="" class="noborder" src="../../../ib/chemistry/images/2014-Options/Option-D/IR-of-aspirin.jpg" style="width: 437px; height: 268px;"></p><hr class="hidden"><p>Explain why there are two peaks in the region 1700 -1750 cm<sup>-1</sup>.</p><hr class="hidden"></div><hr class="hidden"><p>This worksheet can also be downloaded from:</p><p><a href="/media/ib/chemistry/files/2014%20practicals/Preparation-of-aspirin.pdf" target="_blank" title="Worksheets"><img class="ico" src="../../../img/icons/exercise-1.png">&nbsp;<img alt="" height="16" src="../../../img/tib-icons/standard-level-24-1.png" title="" width="16"> <img alt="" height="16" src="../../../img/tib-icons/higher-level-24-1.png" title="" width="16"> Preparation &amp; purification of aspirin</a></p></section></article><section id="media-extras"><div class="page-actions no-print navbar inline hidden-desktop"><div class="navbar-inner"><ul class="nav"><li><a class="presentation" href="#" onclick="return false;"><i class="fa fa-desktop"></i></a></li><li><a class="print-section-blog" href="#" onclick="return false;"><i class="fa fa-print"></i></a></li><li><a class="page-bookmarker" data-ticket="IB Docs (2) Team" data-pid="19159" href="#" onclick="return false;"><i class="fa fa-star"></i></a></li><li><a class="personal-notes" href="#" onclick="return false;"><i class="fa fa-file-text"></i></a></li><li><a class="" data-toggle="modal" href="#modal-feedback" onclick="return false;"><i class="fa fa-envelope-o"></i></a></li><li class="dropdown"><a class="dropdown-toggle" data-toggle="dropdown" data-target="#" href="#"><i class="fa fa-share-alt"></i></a><ul class="dropdown-menu" role="menu"><li><a class="" target="_blank" title="Share on Twitter" href="https://twitter.com/share?text=%22Preparation+%26+purification+of+aspirin+%22+-+via+%40InThinker+%23chemistry%0A&url=https%3A%2F%2Fwww.thinkib.net%2Fchemistry%2Fpage%2F19159%2Fpreparation-purification-of-aspirin-"><i class="fa fa-twitter-square"></i><span>Twitter</span></a></li><li><a class="" target="_blank" title="Share on Facebook" href="https://www.facebook.com/sharer.php?u=https%3A%2F%2Fwww.thinkib.net%2Fchemistry%2Fpage%2F19159%2Fpreparation-purification-of-aspirin-&t=Preparation+&+purification+of+aspirin+"><i class="fa fa-facebook-square"></i><span>Facebook</span></a></li><li><a class="" href="http://www.linkedin.com/shareArticle?mini=true&url=https%3A%2F%2Fwww.thinkib.net%2Fchemistry%2Fpage%2F19159%2Fpreparation-purification-of-aspirin-"><i class="fa fa-linkedin-square"></i><span>LinkedIn</span></a></li><li><a class="" href="https://plus.google.com/share?url=https%3A%2F%2Fwww.thinkib.net%2Fchemistry%2Fpage%2F19159%2Fpreparation-purification-of-aspirin-"><i class="fa fa-google-plus-square"></i><span>Google +</span></a></li><li><a class="" href="mailto:?subject=Preparation & purification of aspirin &body=The photograph of the packet above is an interesting image as each tablet contains 75 mg of aspirin. When aspirin is taken to relieve the symptoms of pain or fever the tablets usually contain 300 mg of aspirin. The 75 mg...%0Ahttps%3A%2F%2Fwww.thinkib.net%2Fchemistry%2Fpage%2F19159%2Fpreparation-purification-of-aspirin-"><i class="fa fa-envelope"></i><span>Email</span></a></li></ul></li><li><a class="" href="chemistry/teaching-materials"><i class="fa fa-puzzle-piece colored"></i></a></li></ul></div></div><div style="border-top: solid 1px #eee;border-bottom: solid 1px #eee;padding: 4px 0 4px 0;line-height: 1em;color: #666;font-size: .8em"><small><em>All materials on this website are for the exclusive use of teachers and students at subscribing schools for the period of their subscription. Any unauthorised copying or posting of materials on other websites is an infringement of our copyright and could result in your account being blocked and legal action being taken against you.</em></small></div></section><section id="comments"></section><div id="std-site-share-link" class="modal fade" tabindex="-1" role="dialog">
  <div class="modal-dialog" role="document">
      <div class="modal-content">
          <div class="modal-body" style="padding: 10px; text-align: center;">
              <p>Click the 'Copy URL' button to copy link to another learning platform (e.g. Google Classroom.).</p>
              <div id="std-link-url" style="font-size: 20px; font-weight: 700;"></div>
              <button id="copy-std-link-url" class="btn btn-default" style="margin-top: 20px;" title="Copy URL to clipboard">
                <i class="fa fa-link"></i> Copy URL
              </button>
          </div>
      </div>
  </div>
</div>
<div id="modal-std-access-tools-add-task" class="modal hide fade">
    <div class="modal-header">
        <button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
        <h3><i class="fa fa-file colored"></i> Preparation & purification of aspirin </h3>

        <label>
            Send to:
            <span id="modal-std-access-tools-recipients" style="font-weight: normal"></span>
        </label>
    </div>

    <div class="modal-body">
        <form id="form-send-page-task">
            <div class="row-fluid">
                <div class="span6">
                    <label>Select deadline</label>
                    <div class="input-prepend">
                        <span class="add-on" style="padding: 6px; cursor: pointer;"><i class="fa fa-calendar"></i></span>
                        <input type="text" name="deadline" class="deadline-datepicker" style="padding: 6px; cursor: pointer;">
                    </div>
                </div>
                <div class="span6" style="display: none">
                    <div class="exam-mode-container">
                        <label>Exam mode</label>
                        <div class="input-prepend">
                            <span class="add-on" style="padding: 6px;">
                                <i class="fa fa-clock-o"></i>
                            </span>
                            <input name="minutes" type="number" min="1" max="120" placeholder="minutes" style="padding: 6px;">
                        </div>
                    </div>
                </div>
            </div>
            <div class="row-fluid">
                <label>Optional instructions</label>
                <div class="row-fluid">
                    <textarea class="span12" name="resource-notes" style="resize: vertical;"></textarea>
                </div>
            </div>
            
            <div class="row-fluid">
                <div class="score-answers-container" style="margin-top: 15px;"></div>
            </div>
            <input type="hidden" name="ticket" value="IB Docs (2) Team">
            <input type="hidden" name="subject-id" value="3">
            <input type="hidden" name="resource-title" value="Preparation & purification of aspirin ">
            <input type="hidden" name="resource-type" value="read">
            <input type="hidden" name="resource-id" value="19159">
            <input type="hidden" name="dynamic-question-ids" id="std-tools-dyn-quiz-ids" value="">
        </form>
    </div>

    <div class="modal-footer">
        <button class="btn" data-dismiss="modal">
            Cancel
        </button>

        <div class="pull-right save-actions">
            <span class="btn disabled hidden">
                <i class="fa fa-spin fa-circle-o-notch"></i>
                Processing...
            </span>

            <a class="save-task-from-tools also-send btn btn-success" disabled="disabled">
                <i class="fa fa-check"></i> Send task
            </a>
        </div>
    </div>
</div>
</div><!-- /#main-column -->
				</div>
			</div><!-- /#content -->
		</div>
	</div>

    <div id="footer">
    <div class="wmap">
        <div class="layout-wrapper">
            <p>
                &copy; <script>document.write(new Date().getFullYear())</script> <em>InThinking / IB Documents (2) Team | Version: 31.01.2023</em>
                &nbsp;| &nbsp;
                <a target="_self" href="/subscribe/about-us">
                    About us
                </a>
                &nbsp;|&nbsp;
                 <a target="_self" href="/subscribe/legal">
                    Legal
                </a>
                &nbsp;|&nbsp;
                <a target="_self" href="/subscribe/contact">
                    Contact
                </a>
            </p>
            <p>
                <a class="social" target="_blank" href="https://twitter.com/inthinker">
                    <img src="../../../social/twitter-square-1.svg"> Twitter
                </a>
                <a class="social" target="_blank" href="https://www.facebook.com/inthinking.net">
                    <img src="../../../social/facebook-square-1.svg"> Facebook
                </a>
                <a class="social" target="_blank" href="https://www.linkedin.com/company/9s4we1">
                    <img src="../../../social/linkedin-square-1.svg"> LinkedIn
                </a>
            </p>
        </div>
    </div>
</div>
<input id="tzoffset" type="hidden" value="-36000"><div id="modal-session-expired" class="modal fade" tabindex="-1" role="dialog" data-backdrop="static" data-keyboard="false">
    <div class="modal-dialog" role="document">
        <div class="modal-content">
            <div class="modal-header">
                <h3 style="margin-top: 0">Your session has expired</h3>
            </div>
            <div class="modal-body" style="padding: 10px;">
                <p>You will have to reload and log in again.</p>
            </div>
            <div class="modal-footer">
                <a id="session-expired" class="btn btn-danger pull-right" href="#">
                    <i class="fa fa-refresh"></i>&nbsp;&nbsp;Reload
                </a>
            </div>
        </div>
    </div>
</div>

	<!-- Loading scripts at the end of the body means faster page loading -->
	<script src="../../../js/jquery-1.10.2.min-1.js"></script>
	<script src="../../../js/bootstrap.min-1.js"></script>
	<script type="text/javascript" src="../../../js/jq-fancybox/jquery.fancybox.pack-1.js"></script>
	<script>var pageId = 19159;</script><script src="../../../js/autosize.min-1.js" media="screen"></script><script src="../../../js/user/section-faves.min-1.js?v=202110111730"></script><script type="text/javascript" src="../../../assets/build/app-1.js?v=202204141130"></script><script type="text/javascript" src="../../../assets/js/ckeditor5-utils.min-1.js?v=20211202"></script><script type="text/javascript" src="../../../js/tib-fullscreen/tib-fullscreen.min-1.js?v=202109221648"></script><script src="../../../js/std-access/std-access-tools.min-1.js?v=202204280950"></script><script src="../../../js/jq-datepicker/bootstrap-datepicker.min-1.js"></script><script src="../../../js/std-access/std-access-tools-add-task.min-1.js?v=202204280950"></script><script src="../../../js/std-access/std-assignments-utils.min-1.js?v=202211281800"></script><script src="../../../js/sidemenu/sidemenu.min-1.js?v=202011301145"></script><script src="../../../js/header-circle.min-1.js?v=20220113"></script><script src="../../../js/password-toggler.min-1.js?v=20220929"></script><script type="text/javascript" src="../../../js/cookies.min-1.js"></script>
<script type="text/javascript">
// The cookies alert
if (! readCookie("displayCookieConsent") && ! readCookie("y") ) {
    var cookieMSG = "We use cookies. By continuing to use this website you are giving consent to cookies being used.";
    setTimeout(function() {
        $.ajax({
            cache: true,
            url: "js/cookiechoices.js",
            dataType: "script",
            success: function () {
                cookieChoices.showCookieConsentBar(cookieMSG, 'close', 'Read more', "chemistry/legal#cookies");
            }
        });
    }, 2000);
}
</script><script>var sAJAX='/pages/activity/user-stats-page.php?t=IB Docs (2) Team&x=19897';var sData='0ebg+I>F/4F[IxZ4hvT)hIn82Oc2UjpCqiT2UMWu]-ruIxZg2|Tg+IbCLvc9o[QgLIb1q|c4+I>1oif)oi+)+InghIb1o[8[UxbMLNbYoiQChNf[5[/[UxbOqNuc2|w6IicY/4FMUxbeqIn9LIb4qTZ80Ipc/4F[2vwOqt/6/Obc2iZQ2|ncIicY/4F[]-YSn-Y[ak==';var loopSecs = 30;var lsKey = '6eb61f8b0594ecb3bc32ded924cfc26c';</script><script src="../../../js/user/user-stats-page.min-1.js?v=202102101800"></script><script>var sessionUpdateSecs = 600;</script><script type="text/javascript" src="../../../js/session-updater-1.js?v=20200831"></script>
	<script type="text/javascript">
		$(document).ready(function(){
			function padLeft(str,max){return str.length<max?padLeft("0"+str,max):str}function padRight(str,max){return str.length<max?padRight(str+"0",max):str}$("body").on("click",'a[href="#"], a.fancybox-nav, a[data-toggle="tab"], a[data-toggle="dropdown"], a[data-toggle="collapse"], a[data-toggle="modal"]',(function(e){e.preventDefault()}));var topmenuOffset=0,topmenuHeight=0;function fixDiv(t,h){$(window).scrollTop()<topmenuOffset||$("#topmenu ul.level-1").is(":visible")?($("#topmenu").css({position:"",width:""}),$("#topmenu").removeClass("fixed-top"),$("body").css({"padding-top":"0"})):($("#topmenu").css({position:"fixed",top:"0",width:$("#topmenu").width()+"px"}),$("#topmenu").addClass("fixed-top"),$("body").css({"padding-top":topmenuHeight+"px"}))}function fixSearchNav(){var searchMenuTop=topmenuOffset+topmenuHeight,searchMenuH=$("#nav-menu-search").is(":visible")?$("#nav-menu-search").outerHeight():0;$(window).scrollTop()>searchMenuTop-topmenuHeight?($("#nav-menu-search").css({position:"fixed",top:topmenuHeight+"px",left:"0",right:"0"}),$("#nav-menu-search").addClass("fixed-top"),$("body").css("padding-top",topmenuHeight+searchMenuH+"px")):($("#nav-menu-search").css({position:""}),$("#nav-menu-search").removeClass("fixed-top"),$("body").css("padding-top","0"))}$("#topmenu").length&&(topmenuOffset=$("#topmenu").offset().top,topmenuHeight=$("#topmenu").outerHeight(),fixDiv(),$(window).scroll((function(){fixDiv(),fixSearchNav()}))),$("a.toggle-menu-search").on("click",(function(e){e.preventDefault(),$("#nav-menu-search").slideToggle("fast",(function(){$(this).find('input[name="s"]').focus()}))}));var menuH=$("#topmenu").height(),itemH=$("#topmenu > nav > ul > li").height();function fancyScrollTo(id){$("html, body").animate({scrollTop:$("#"+id).offset().top-300},300)}function printSectionBlog(){var w=$(window).width()/2,h,windowSettings="height="+($(window).height()-100)+", width="+w+", left=0, top=0, resizable=no, ";windowSettings+="scrollbars=yes, toolbar=no, menubar=no, location=no, ",windowSettings+="directories=no, status=yes";var myWindow=window.open("","Page printer",windowSettings),containerHtml=["<html>","<head>","<title>Page printer</title>",'<link rel="stylesheet" type="text/css" href="'+window.location.origin+'/css/style.min.css?v=202211152130">','<link rel="stylesheet" type="text/css" href="'+window.location.origin+"/css/style"+SITE_TAG+'.min.css?v=202104061357">','<link rel="stylesheet" type="text/css" href="'+window.location.origin+'/css/snippets.min.css?v=202210181500">','<link rel="stylesheet" type="text/css" href="'+window.location.origin+'/css/article.min.css?v=202210181500">',"</head>","<body>",$("section#main-content").html().replace(/<span\sclass="MJX_Assistive_MathML".*?<\/span>/g,""),"</body>","</html>"].join("");containerHtml=containerHtml.replace(/src="files\//gi,'src="'+window.location.origin+"/files/"),myWindow.document.write(containerHtml),myWindow.document.close(),myWindow.focus(),setTimeout((function(){$.when(myWindow.print()).then(myWindow.close())}),1e3)}function PopupPrint(target){window.print()}$("#topmenu > nav > ul > li").each((function(){if(menuH>itemH&&$(this).position().top<1){var i=itemH+1;$(this).find("ul:first").css("margin-top","-"+i+"px")}})),$("#topmenu > nav > ul > li").on("mouseenter mouseleave",(function(e){var submenu=$("ul:first",this),submenuW=submenu.width();$(this).offset().left+submenuW>$(window).width()&&(submenu.css("right","0"),submenu.find("ul").each((function(){if(!$(this).hasClass("fixed")){var l=$(this).width()+submenuW;$(this).css("margin-left","-"+l+"px"),$(this).addClass("fixed")}})))})),$("a.showhider").click((function(e){e.preventDefault();var box="#"+$(this).attr("rel"),show='<i class="fa fa-eye"></i>',hide='<i class="fa fa-eye-slash"></i>';$(box).slideToggle("fast"),$(this).html($(this).html()==show?hide:show),$(this).attr("title","Show"==$(this).attr("title")?"Hide":"Show")})),$("a.scroll-to").click((function(e){e.preventDefault();var n=$("#"+$(this).data("target")).offset().top-70;$("html, body").animate({scrollTop:n},300)})),$("a.print-section-blog").click((function(e){e.preventDefault(),printSectionBlog()})),$(".print-button").click((function(e){var target;e.preventDefault(),PopupPrint("#"+$(this).data("target-id"))})),$(".alert.alert-success").delay(6e3).hide("fast",fixDiv());var fancyParent=1==$("body").find($("#main-article")).length?"#main-article":"body",fancyOptions={loop:!1,openEffect:"elastic",closeEffect:"elastic",nextEffect:"fade",prevEffect:"fade",parent:fancyParent,helpers:{title:{type:"inside"}}};if($("ul.gallery").each((function(){var rel=$(this).find("li:first-child > a:first-child").attr("rel");$('ul.gallery a.fancy[rel="'+rel+'"]').fancybox(fancyOptions)})),$(".carousel.slide").each((function(){var rel="gallery-"+$(this).data("id");$('.carousel.slide a.fancy[rel="'+rel+'"]').fancybox(fancyOptions)})),$("img.pop").parent("a").each((function(){$(this).attr("title",$(this).children("img").attr("alt"))})),$("img.pop").parent("a").fancybox({loop:!1,helpers:{title:{type:"inside"}}}),!are_cookies_enabled()){var msg='<div class="alert alert-error"><i class="fa fa-warning"></i> Your browser does not accept cookies from this site. Please enable cookies to log in.</div><div class="alert alert-info"><i class="fa fa-question-circle"></i> Enabling cookies in <a target="_blank" style="margin: 0; padding: 0;" href="https://support.mozilla.org/en-US/kb/enable-and-disable-cookies-website-preferences">Firefox</a>, <a target="_blank" style="margin: 0; padding: 0;" href="https://support.google.com/accounts/answer/61416?hl=en">Chrome</a>, <a target="_blank" style="margin: 0; padding: 0;" href="http://windows.microsoft.com/en-us/windows-vista/block-or-allow-cookies">Explorer</a></div>';$("#modal-login .modal-header").append(msg)}if($(".panel-expandable > .panel-heading").click((function(e){e.preventDefault();var panel=$(this).closest(".panel-expandable"),expandables=panel.hasClass("panel-has-footer")?".panel-body, .panel-footer":".panel-body";panel.find(".panel-body").is(":visible")?(panel.find(expandables).slideUp("fast"),panel.find(".expander > .fa-minus").removeClass("fa-minus").addClass("fa-plus")):(panel.find(expandables).slideDown("fast"),panel.find(".expander > .fa-plus").removeClass("fa-plus").addClass("fa-minus"))})),$("#modal-find-out-more").css({width:.8*$("#container").width()+"px","margin-left":-.4*$("#container").width()+"px"}),$(".modal-xxl").length){var modalTopPos=Math.round(.07*$(window).height());$(window).width()>1200&&$(".modal-xxl").css({"max-width":$(window).width()>960?"960px":$(window).width()+"px",width:$(window).width()>960?"960px":$(window).width()+"px","margin-left":$(window).width()>960?"-480px":Math.round($(window).width()/2)}),$(".modal-xxl").css("top",modalTopPos+"px"),$(".modal-xxl").on("shown",(function(){var mHeaderH=$(this).find(".modal-header").outerHeight(),mBody=$(this).find(".modal-body"),mBodyH=mBody.outerHeight(),mFooterH=$(this).find(".modal-footer").outerHeight(),bottomOfTheModal=modalTopPos+mHeaderH+mBodyH+mFooterH;if(bottomOfTheModal<$(window).height())mBodyH+=$(window).height()-bottomOfTheModal-60,mBody.css("max-height",mBodyH+"px");else{$(window).scrollTop(0),modalTopPos=10,$(".modal-xxl").css("top",modalTopPos+"px"),bottomOfTheModal=modalTopPos+mHeaderH+mBodyH+mFooterH,availableScroll=bottomOfTheModal-$(window).height()+modalTopPos;var lastPos=-1;$(window).on("scroll",(function(){var s=$(window).scrollTop()>availableScroll?availableScroll:$(window).scrollTop();newPos=modalTopPos-s,newPos!=lastPos&&($(".modal-xxl").css("top",newPos+"px"),lastPos=newPos)}))}}))}function popupHelp(url,title,w,h){var dualScreenLeft=void 0!==window.screenLeft?window.screenLeft:screen.left,dualScreenTop=void 0!==window.screenTop?window.screenTop:screen.top,width,height,left=(window.innerWidth?window.innerWidth:document.documentElement.clientWidth?document.documentElement.clientWidth:screen.width)/2-w/2+dualScreenLeft,top=(window.innerHeight?window.innerHeight:document.documentElement.clientHeight?document.documentElement.clientHeight:screen.height)/2-h/2+dualScreenTop,newWindow=window.open(url,title,"menubar=no,location=no,resizable=0, width="+w+", height="+h+", top="+top+", left="+left);return window.focus&&(newWindow?newWindow.focus():$('<div class="alert alert-warning" style="margin-bottom: 0px;"><p class="help-block">Pop Up blocked. Please allow Pop Ups in your browser settings.</p></div>').insertBefore("body")),newWindow}if($(".open-student-access-help").click((function(e){e.preventDefault();var h=$(window).height()-20,w=$(window).width()<1280?$(window).width():1280;popupHelp(helpURL,"Student Access Help",w,h)})),$(".pop-up-help").click((function(e){e.preventDefault();var url=$(this).attr("href"),title=$(this).data("title"),h=$(window).height()-20,w;popupHelp(url,title,$(window).width()<1280?$(window).width():1280,h)})),$("section.tib-hiddenbox").length){var count=0;$($("section.tib-hiddenbox").get().reverse()).each((function(){var box=$(this),revealButton;$("<a />").attr("class","btn showhider").attr("rel","hiddenBoxContent"+count).attr("style","margin-bottom: 0;").html('<i class="fa fa-eye"></i>').insertBefore(box);var newContainer=$("<div />").attr("class","hidden-content").attr("id","hiddenBoxContent"+count).html(box.html());newContainer.hide(),newContainer.insertBefore(box),box.remove(),count++})),$("a.showhider").on("click",(function(e){var container=$("#"+$(this).attr("rel"));container.is(":hidden")?(container.fadeIn("fast"),$(this).html('<i class="fa fa-eye-slash"></i>')):(container.fadeOut("fast"),$(this).html('<i class="fa fa-eye"></i>'))}))}
			function loadComments(){$.get("pages/comment.php",{action:"get-list",ticket:"IB Docs (2) Team",site_with_comments:"1",general_id:"3",sitename:"chemistry",section_id:"19159"},(function(t){"1"==t.success?($("#comments").html(t.html),"undefined"!=typeof CKEDITOR&&initCommentsEditor()):alert("Error (lc1): please contact support")}),"json")}$(document).ready((function(){loadComments()}));let commentEditor={};function initCommentsEditor(){const t=document.querySelector("#comment-content");t&&CKEDITOR.BasicEditor.create(t,{toolbar:{viewportTopOffset:50,items:["bold","italic","link","subscript","superscript"]},link:{decorators:{addLinkNoFollow:{mode:"automatic",callback:function(t){if(null!=t)return["http://","http://www","https://","https://www","ftp:"].some((o=>t.startsWith(o)))},attributes:{target:"_blank",class:"ck-link",rel:"nofollow"}}}}}).then((function(t){commentEditor=t,commentEditor.execute("heading",{value:"paragraph"})})).catch((function(t){console.error(t)}))}function replaceComment(content,commentId){$("#cancel-comment-post").trigger("click"),$("#comm-"+commentId+" > .comment-content div.comment-text").html(content)}function placeComment(html,fatherId){$("#comment-form").hide(),$("#comment-form textarea").val(""),fatherId>0?($("#comments #comm-"+fatherId).append(html),$("#comments").append($("#comment-form"))):$("#comments").append(html).append($("#comment-form")),$(".comment .fa-arrow-down").removeClass("fa-arrow-down").addClass("fa-reply"),$(".comment-content").removeClass("marked"),$("#comment-form").show("fast")}function update_sticky_comments(arrIds,mode){$.post("pages/edit/update-sticky-comments.php?mode="+mode,{ids:arrIds,ticket:$("#comment-ticket").val()},(function(data){1==data.success?("set"==data.mode&&$("#sticky-"+data.id).parents("div.comment").each((function(e){$(this).find("a.pull-right").first().addClass("sticky"),$(this).find("a.pull-right").first().attr("title","Unmark as important")})),"unset"==data.mode&&($("#sticky-"+data.id).removeClass("sticky"),$("#sticky-"+data.id).attr("title","Mark as important"),$("#sticky-"+data.id).closest("div.comment").find("div.comment").each((function(e){$(this).find("a.pull-right").first().removeClass("sticky"),$(this).find("a.pull-right").first().attr("title","Mark as important")})))):alert(data.error)}),"json")}"undefined"!=typeof CKEDITOR&&initCommentsEditor(),$("section#comments").on("click","#edit-comment",(function(e){e.preventDefault();var commentId=$("form#comment-form #comment-mode").val(),commentContent=commentEditor.getData(),ticket=$("#comment-ticket").val(),sectionId=$("#section-id").val();$.post("pages/comment.php",{action:"edit",comment_id:commentId,content:commentContent,ticket:ticket},(function(data){"0"==data.success?alert(data.error):replaceComment(data.text,commentId)}),"json")})),$("section#comments").on("click","a.edit-comment",(function(e){e.preventDefault(),$(".comment .hidden").removeClass("hidden");var commentId=$(this).data("comment-id"),form=$("form#comment-form"),text=$("#comm-"+commentId+" > .comment-content div.comment-text").html();commentEditor.setData(text),$("form#comment-form textarea").val(""),$("form#comment-form textarea").val(text),$("#comm-"+commentId+" > .comment-content > img").addClass("hidden"),$("#comm-"+commentId+" > .comment-content > div.comment-text").addClass("hidden"),$("#comm-"+commentId+" > .comment-footer").addClass("hidden"),$("#comm-"+commentId+" > .comment-content").append(form),$("form#comment-form #submit-comment").hide(),$("form#comment-form #edit-comment").show(),$("form#comment-form #cancel-comment-post").show(),$("form#comment-form #comment-mode").val(commentId),fancyScrollTo("comment-form"),$("form#comment-form textarea").focus()})),$("section#comments").on("click","#submit-comment",(function(e){e.preventDefault();var commentContent=commentEditor.getData(),fatherId=$("#father-comment").val(),ticket=$("#comment-ticket").val(),sectionId=$("#section-id").val();$.post("pages/comment.php",{action:"post",section_id:sectionId,father_id:fatherId,content:commentContent,ticket:ticket},(function(data){if("0"==data.success)alert(data.error);else{commentEditor.setData(""),placeComment(data.html,fatherId),$("form#comment-form #cancel-comment-post").hide();var n=0;$("#n-comments").text().length>0&&(n=parseInt($("#n-comments").text())),$("#n-comments").text(n+1)}}),"json")})),$("section#comments").on("click","a.reply-comment",(function(e){e.preventDefault(),$(".comment .fa-arrow-down").removeClass("fa-arrow-down").addClass("fa-reply"),$(".comment-content").removeClass("marked");var form=$("form#comment-form"),fatherId=$(this).parent().parent(".comment").attr("rel");form.find("#father-comment").val(fatherId),$(this).parent().parent(".comment").find("> .reply-area").append(form),$(this).find(".fa-reply").removeClass("fa-reply").addClass("fa-arrow-down"),$(this).parent().prev(".comment-content").addClass("marked"),$("form#comment-form #cancel-comment-post").show(),fancyScrollTo("comment-form"),$("form#comment-form textarea").focus()})),$("section#comments").on("click","#cancel-comment-post",(function(e){e.preventDefault(),$(".comment .hidden").removeClass("hidden"),$(".comment .fa-arrow-down").removeClass("fa-arrow-down").addClass("fa-reply"),$(".comment-content.marked").removeClass("marked"),commentEditor.setData("");var form=$("form#comment-form");$("section#comments").append(form),$("form#comment-form #father-comment").val("0"),$("form#comment-form textarea").val(""),$("form#comment-form #comment-mode").val("new"),$("#edit-comment").hide(),$(this).hide(),$("#submit-comment").show()})),$("section#comments").on("click","a.delete-comment",(function(e){var commentId=$(this).data("comment-id"),isFather=$("#comm-"+commentId).children(".comment").length>0,ticket=$("#comment-ticket").val(),msg="You are going to delete a comment.\n\nThis action cannot be undone.\n\nAre you sure?";isFather&&(msg="You are going to delete a comment and all its replies.\n\nThis action cannot be undone.\n\nAre you sure?"),confirm(msg)&&$.post("pages/comment.php",{action:"delete",comment_id:commentId,is_father:isFather,ticket:ticket},(function(data){if("0"==data.success)alert(data.error);else{$("#comm-"+commentId+".comment").replaceWith(data.text);var n=0;$("#n-comments").text().length&&(n=parseInt($("#n-comments").text())),$("#n-comments").text(n-parseInt(data.deleted))}}),"json"),e.preventDefault(),e.stopPropagation()})),$("section#comments").on("click","a.pull-right",(function(e){e.preventDefault();var arrayIds=[];$(this).hasClass("sticky")?(arrayIds.push($(this).closest("div.comment").attr("rel")),$(this).closest("div.comment").find("div.comment").each((function(e){arrayIds.push($(this).attr("rel"))})),update_sticky_comments(arrayIds,"unset")):($(this).parents("div.comment").each((function(e){arrayIds.push($(this).attr("rel"))})),update_sticky_comments(arrayIds,"set"))}));$('#tl-tabs a').click(function (e) {e.preventDefault();$(this).tab('show');});$('img.ico[src="/img/icons/comments.png"]').each((function(){var comment=$(this).attr("title");$(this).removeAttr("title"),$(this).wrap('<a class="tib-popover" href="#" data-content="'+comment+'" data-togle="popover" data-placement="top" />')})),$('img.ico[src="img/icons/comments.png"]').each((function(){var comment=$(this).attr("title");$(this).removeAttr("title"),$(this).wrap('<a class="tib-popover" href="#" data-content="'+comment+'" data-togle="popover" data-placement="top" />')})),$(".tib-popover").popover({html:!0,trigger:"hover",delay:{show:300,hide:300},placement:function(context,source){var position=$(source).position();return position.top>200?"top":position.left<515?"right":position.top<200?"bottom":position.left>515?"left":"top"}}).click((function(e){e.preventDefault()}));var carouselTime=6500;$("div.carousel.slide").carousel({interval:carouselTime}),$(".tib-indicators > img").click((function(){var index=$(this).index(),container;$(this).closest(".carousel.slide").carousel(index)}));
$('a.btn.showhider').click(function(e) {
    var showHiderId = $( this ).attr('rel');
    if ( $('#'+showHiderId).find('iframe').length > 0 ) {
        $('#'+showHiderId+' iframe').each(function() {
            if ( $(this).attr('src').indexOf('.pdf') > 0 ) {
                this.contentWindow.location.reload(true);
            }
        });
    }
});

var hTopmenu = $('#topmenu').height();
var n = 0;
$('nav.top-nav > ul > li').each(function(k, e) {
    if (n > 1) {
        var diff = hTopmenu-(e.offsetTop+e.offsetHeight);
        $(e).find(' > ul ').css('margin-top', '-'+diff+'px');
    }
    n++;
});

		});
	</script>
</body>
</html>