File "electrochemical-cells-ii.html"
Path: /StudyIB/chemistry/page/907/electrochemical-cells-iihtml
File size: 70.44 KB
MIME-type: text/html
Charset: utf-8
<!DOCTYPE html><html lang="EN"><head> <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-PZBWZ8J');</script> <title>Electrochemical cells II</title><!-- Removed by WebCopy --><!--<base href="/">--><!-- Removed by WebCopy --><meta http-equiv="x-ua-compatible" content="IE=Edge"><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1"><link href="../../../css/bootstrap.flatly.min.css" rel="stylesheet" media="screen"><link rel="stylesheet" href="../../../fonts/awesome/css/font-awesome.min.css"><link href="../../../js/jquery-fancybox/jquery.fancybox.min.css" type="text/css" rel="stylesheet"><link rel="stylesheet" href="../../../css/style.min.css?v=202301301645"><meta name="robots" content="index, follow"><meta name="googlebot" content="noarchive"><meta prefix="og: http://ogp.me/ns#" property="og:title" name="og:title" content="StudyIB Chemistry: Electrochemical cells II"> <meta prefix="og: http://ogp.me/ns#" property="og:image" content="https://studyib.net/img/studyib-card-default.jpg"> <meta prefix="og: http://ogp.me/ns#" property="og:description" name="og:description" content="Topic 19.1 Further exploration of our understanding of electrochemical cells."> <meta prefix="og: http://ogp.me/ns#" property="og:url" name="og:url" content="https://studyib.net/chemistry/page/907/electrochemical-cells-ii"> <meta prefix="og: http://ogp.me/ns#" property="og:site_name" name="og:site_name" content="StudyIB - Your IB learning companion"> <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="Topic 19.1 Further exploration of our understanding of electrochemical cells."> <meta name="image" content="https://studyib.net/img/studyib-card-default.jpg"> <meta name="keywords" content="IB, IBDP, InThinking, International Baccalaureate, Revision, Revision websites, Student Sites, Students, Learning, Guidance, Exam, Questions, Practice problems, Diagnose, Help, Notes"> <meta itemprop="name" content="StudyIB Chemistry: Electrochemical cells II"> <meta itemprop="description" content="Topic 19.1 Further exploration of our understanding of electrochemical cells."> <meta itemprop="image" content="https://studyib.net/img/studyib-card-default.jpg"> <meta name="twitter:card" content="summary_large_image"> <meta name="twitter:title" content="StudyIB Chemistry: Electrochemical cells II"> <meta name="twitter:description" content="Topic 19.1 Further exploration of our understanding of electrochemical cells."> <meta name="twitter:image" content="https://studyib.net/img/studyib-card-default.jpg"> <meta name="twitter:creator" content="@inthinker"><link rel="stylesheet" href="../../../css/snippets.min.css?v=202209111300"><link rel="stylesheet" href="../../../css/article.min.css?v=202211221000"><link rel="stylesheet" type="text/css" href="../../../css/flashcards/flashcards.min.css?v=202211221000"><link rel="stylesheet" href="../../../css/flashcards/magic.min.css"><style type="text/css">.filter-sl-only { display: none; }</style><script src="../../../js/ifvisible.min.js"></script><script>ifvisible.setIdleDuration(300);</script><link rel="apple-touch-icon-precomposed" sizes="57x57" href="../../../img/favicon/apple-touch-icon-57x57.png"> <link rel="apple-touch-icon-precomposed" sizes="114x114" href="../../../img/favicon/apple-touch-icon-114x114.png"> <link rel="apple-touch-icon-precomposed" sizes="72x72" href="../../../img/favicon/apple-touch-icon-72x72.png"> <link rel="apple-touch-icon-precomposed" sizes="144x144" href="../../../img/favicon/apple-touch-icon-144x144.png"> <link rel="apple-touch-icon-precomposed" sizes="60x60" href="../../../img/favicon/apple-touch-icon-60x60.png"> <link rel="apple-touch-icon-precomposed" sizes="120x120" href="../../../img/favicon/apple-touch-icon-120x120.png"> <link rel="apple-touch-icon-precomposed" sizes="76x76" href="../../../img/favicon/apple-touch-icon-76x76.png"> <link rel="apple-touch-icon-precomposed" sizes="152x152" href="../../../img/favicon/apple-touch-icon-152x152.png"> <link rel="icon" type="image/png" href="../../../img/favicon/favicon-196x196.png" sizes="196x196"> <link rel="icon" type="image/png" href="../../../img/favicon/favicon-96x96.png" sizes="96x96"> <link rel="icon" type="image/png" href="../../../img/favicon/favicon-32x32.png" sizes="32x32"> <link rel="icon" type="image/png" href="../../../img/favicon/favicon-16x16.png" sizes="16x16"> <link rel="icon" type="image/png" href="../../../img/favicon/favicon-128.png" sizes="128x128"> <meta name="application-name" content="StudyIB: Your IB Learning Companion"> <meta name="msapplication-TileColor" content="#A5BED5"> <meta name="msapplication-TileImage" content="/img/favicon/mstile-144x144.png"> <meta name="msapplication-square70x70logo" content="/img/favicon/mstile-70x70.png"> <meta name="msapplication-square150x150logo" content="/img/favicon/mstile-150x150.png"> <meta name="msapplication-wide310x150logo" content="/img/favicon/mstile-310x150.png"> <meta name="msapplication-square310x310logo" content="/img/favicon/mstile-310x310.png"><script>var stdHash = "6da675cbcb3d25f050b05557349abc79", stdTicket = "082b9c9c4ae3624d";</script><script src="../../../js/user/local-stats.min.js?v=202205311700"></script><link href="../../../css/subjects-frontpage.min.css?v=202302031000" rel="stylesheet"></head><body class="public chemistry"> <noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-PZBWZ8J" height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript> <div id="top-header"> <div class="wmap general hidden-sm hidden-xs subjects"> <div class="layout-wrapper"> <div class="container-fluid"> <a href=""> <img class="header-thinker" src="../../../img/header-thinker.svg"> </a> <h1> <a href="../../../chemistry.html"> IBDP Chemistry </a> <a href="https://inthinking.net" title="inthinking.net" class="inthinking-logo pull-right"> <img src="../../../img/header-logo.svg" style="height: 80px; width: auto;"> </a> </h1> <p class="slogan">InThinking Revision Sites for students</p> <p class="author">Website by <strong>Paul Lloyd</strong></p> <p class="updated">Updated 1 February 2023</p> </div> </div> </div> <nav id="public-topnav" class="navbar navbar-default"> <div class="container-fluid"> <div class="navbar-header"> <a class="navbar-brand hidden-md hidden-lg" href="../../../index.htm"> <img class="header-xs-thinker" src="../../../img/header-thinker.svg"> </a> <button type="button" class="collapsed navbar-toggle" data-toggle="collapse" data-target="#subject-navbar-collapse" aria-expanded="false"> <span class="sr-only">Toggle navigation</span> <i class="fa fa-fw fa-2x fa-user"></i> </button> <div class="brand hidden-lg hidden-md hidden-sm"> <a class="brand-xs" href="../../../chemistry.html"> <strong class="title" style="white-space: nowrap;font-size: 18px;">Chemistry</strong> </a> </div> </div> <div class="collapse navbar-collapse" id="subject-navbar-collapse"> <ul class="nav navbar-bar navbar-userbox hidden-md hidden-lg"><li class="dropdown"><a href="#" class="dropdown-toggle" data-toggle="dropdown"><i class="fa fa-fw fa-lg fa-user-circle" style="margin-right: 5px;"></i><span style="font-size: 16px;"></span></a><ul class="dropdown-menu"><li class="dropdown-submenu"><a class="dropdown-toggle" href="#" data-toggle="dropdown"><i class="fa fa-fw fa-globe"></i> Subjects</a><ul class="dropdown-menu"><li></li><li class=""><a href="../../../biology.html">DP Biology</a></li><li class="active"><a href="../../../chemistry.html"><i class="fa fa-caret-right"></i> DP Chemistry</a></li><li class=""><a href="../../../englishalanglit.html">DP English A: Language & Literature</a></li><li class=""><a href="../../../mathsanalysis.html">DP Maths: Analysis & Approaches</a></li><li class=""><a href="../../../mathsapplications.html">DP Maths: Applications & Interpretations SL</a></li><li class=""><a href="../../../physics.html">DP Physics</a></li><li class=""><a href="../../../spanishb.html">DP Spanish B</a></li></ul></li><li class="menu-item"><a href="../../../user.html"><i class="fa fa-fw fa-dashboard"></i> Dashboard</a></li><li class="menu-item"><a href="../../../user/profile.html"><i class="fa fa-fw fa-cog"></i> My profile</a></li><li class="menu-item"><a href="../../../user/messages.html"><i class="fa fa-fw fa-envelope"></i> Messages</a></li><li class="menu-item hidden-md hidden-lg mt-xs-3"><a href="../../../index.htm?logout=1" class="btn btn-primary btn-xs-block"><i class="fa fa-fw fa-lg fa-power-off text-danger"></i>Log out</a></li></ul></li></ul> <ul class="nav navbar-bar"><li class=""><a class="home" href="../../../chemistry.html"><i class="fa fa-fw fa-home"></i> Home</a></li><li class=""><a class="topics" href="#"><i class="fa fa-fw fa-th-large"></i> Topics</a></li><li class=""><a class="favorites" href="../../../chemistry.html"><i class="fa fa-fw fa-star"></i> My favorites</a></li><li class=""><a class="" href="../../flashcards.html"><i class="fa fa-fw fa-bolt"></i> Flashcards</a></li><li class=""><a class="qbank" href="../../test-your-knowledge.html"><i class="fa fa-fw fa-question"></i> Question bank</a></li><li class=""><a class="networks" href="../../networks.html"><i class="fa fa-fw fa-graduation-cap"></i> Virtual tutor</a></li><li class=""><a class="" href="../../blogs.html"><i class="fa fa-fw fa-paperclip"></i> Blog</a></li><li class=""><a class="sitemap" href="../../sitemap.html"><i class="fa fa-fw fa-sitemap"></i> Sitemap</a></li><li class=""><a class="activity" href="../../../chemistry.html"><i class="fa fa-fw fa-calendar-check-o"></i> My activity</a></li></ul> <ul class="nav navbar-bar navbar-right"> <li> <form class="navbar-form hidden-md hidden-lg" role="search" method="get" action="chemistry/search"> <div class="input-group"> <input class="form-control nav-search" name="glob" type="search" placeholder="Search..."> <span class="input-group-btn"> <button type="submit" class="btn bg-blue"> <i class="fa fa-search"> </i> </button> </span> </div> </form> <a href="#" class="toggle-menu-search hidden-sm hidden-xs" data-toggle="dropdown"> <i class="fa fa-lg fa-search"></i> </a> </li></ul> </div> </div></nav><nav id="nav-menu-search" class="shadow-bottom hidden-sm hidden-xs" style="display: none;"> <div class="container-fluid"> <form class="" role="search" method="get" action="chemistry/search"> <input class="form-control nav-search" name="glob" type="search" placeholder="Search Chemistry..."> <button class="btn btn-sm btn-primary" type="submit"> Search </button> </form> </div></nav><div class="modal fade" tabindex="-1" role="dialog" id="modal-mini-login"> <div class="modal-dialog" role="document"> <div class="modal-content"> <div class="modal-body"> <button aria-hidden="true" data-dismiss="modal" class="close hidden-xs login-button-close" type="button">×</button> <form method="post"> <div class="form-group"> <input name="user-email" class="form-control" type="text" placeholder="Email"> </div> <div class="form-group"> <input name="user-password" class="form-control" type="password" placeholder="Password"> <input name="user-fp" class="fp" value="d8c893da5db7501669ffeeac46273ba6" type="hidden"> </div> <div class="form-group"> <a href="../../../reset-password.html" class="reset-password" style="font-weight: normal;"> Forgot your password? </a> </div> <div class="form-group"> <button type="submit" name="submit-login" value="1" class="btn btn-primary btn-block text-center"> <i class="fa fa-user fa-fw"></i> Log in </button> </div> </form> </div> </div> </div></div></div><div class="modal fade" id="show-topics" tabindex="-1" role="dialog"><div id="dialog-topics" class="modal-dialog modal-dialog-topics"><div class="modal-content"><div class="modal-body modal-body-topics"><div id="new-frontpage-toplevels-topics" class="frontpage-box"><div class="row"><div class="col-md-4 col-sm-4"><div class="item"><a href="../3004/free-access-weekend.html"><div class="header" style="height: 35px;"><h3 class="title special" style="margin-top: 0;">Free Access Weekend!</h3></div><div class="body"><div class="cropper" style="background-image: url('../../images/general-images/free.jpg'); height: 10vw;"></div></div></a></div></div><div class="col-md-4 col-sm-4"><div class="item"><a href="../2075/paper-1-exam-questions.html"><div class="header" style="height: 35px;"><h3 class="title special" style="margin-top: 0;">Paper 1 Exam Questions</h3></div><div class="body"><div class="cropper" style="background-image: url('../../images/test-images/exams.jpg'); height: 10vw;"></div></div></a></div></div><div class="col-md-4 col-sm-4"><div class="item"><a href="../2124/paper-2-exam-questions.html"><div class="header" style="height: 35px;"><h3 class="title special" style="margin-top: 0;">Paper 2 Exam Questions</h3></div><div class="body"><div class="cropper" style="background-image: url('../../images/general-images/paper-2.2.png'); height: 10vw;"></div></div></a></div></div><div class="col-md-4 col-sm-4"><div class="item"><a href="../1138/start-here.html"><div class="header" style="height: 35px;"><h3 class="title special" style="margin-top: 0;">Start Here</h3></div><div class="body"><div class="cropper" style="background-image: url('../../images/general-images/start-here.jpg'); height: 10vw;"></div></div></a></div></div><div class="col-md-4 col-sm-4"><div class="item"><a href="../343/stoichiometry.html"><div class="header" style="height: 35px;"><h3 class="title special" style="margin-top: 0;">Stoichiometry</h3></div><div class="body"><div class="cropper" style="background-image: url('../../images/stoichiometry/scales-1333455_640.jpg'); height: 10vw;"></div></div></a></div></div><div class="col-md-4 col-sm-4"><div class="item"><a href="../355/atomic-structure.html"><div class="header" style="height: 35px;"><h3 class="title special" style="margin-top: 0;">Atomic Structure</h3></div><div class="body"><div class="cropper" style="background-image: url('../../images/atomic-structure/the-atom.png'); height: 10vw;"></div></div></a></div></div><div class="col-md-4 col-sm-4"><div class="item"><a href="../356/periodicity.html"><div class="header" style="height: 35px;"><h3 class="title special" style="margin-top: 0;">Periodicity</h3></div><div class="body"><div class="cropper" style="background-image: url('/media/chemistry/images/periodicity/p-block.png'); height: 10vw;"></div></div></a></div></div><div class="col-md-4 col-sm-4"><div class="item"><a href="../357/bonding-and-structure.html"><div class="header" style="height: 35px;"><h3 class="title special" style="margin-top: 0;">Bonding & Structure</h3></div><div class="body"><div class="cropper" style="background-image: url('/media/chemistry/images/chemical-bonding-and-structure/crystallize-482971_640.jpg'); height: 10vw;"></div></div></a></div></div><div class="col-md-4 col-sm-4"><div class="item"><a href="../358/energetics.html"><div class="header" style="height: 35px;"><h3 class="title special" style="margin-top: 0;">Energetics</h3></div><div class="body"><div class="cropper" style="background-image: url('/media/chemistry/images/energetics-thermochemistry/fire-1030751_640.jpg'); height: 10vw;"></div></div></a></div></div><div class="col-md-4 col-sm-4"><div class="item"><a href="../359/kinetics.html"><div class="header" style="height: 35px;"><h3 class="title special" style="margin-top: 0;">Kinetics</h3></div><div class="body"><div class="cropper" style="background-image: url('/media/chemistry/images/chemical-kinetics/time-731110_640.jpg'); height: 10vw;"></div></div></a></div></div><div class="col-md-4 col-sm-4"><div class="item"><a href="../360/equilibrium.html"><div class="header" style="height: 35px;"><h3 class="title special" style="margin-top: 0;">Equilibrium</h3></div><div class="body"><div class="cropper" style="background-image: url('/media/chemistry/images/equilibrium/soda-466542_640.jpg'); height: 10vw;"></div></div></a></div></div><div class="col-md-4 col-sm-4"><div class="item"><a href="../361/acids-and-bases.html"><div class="header" style="height: 35px;"><h3 class="title special" style="margin-top: 0;">Acids & Bases</h3></div><div class="body"><div class="cropper" style="background-image: url('../../images/acids-and-bases/ui-paper-2.png'); height: 10vw;"></div></div></a></div></div><div class="col-md-4 col-sm-4"><div class="item"><a href="../362/redox-processes.html"><div class="header" style="height: 35px;"><h3 class="title special" style="margin-top: 0;">Redox Processes</h3></div><div class="body"><div class="cropper" style="background-image: url('/media/chemistry/images/redox-processes/oxide-1241222_640.jpg'); height: 10vw;"></div></div></a></div></div><div class="col-md-4 col-sm-4"><div class="item"><a href="../342/organic-chemistry.html"><div class="header" style="height: 35px;"><h3 class="title special" style="margin-top: 0;">Organic Chemistry</h3></div><div class="body"><div class="cropper" style="background-image: url('../../images/organic-chemistry/d-idose_molekulbaukasten_9173.jpg'); height: 10vw;"></div></div></a></div></div><div class="col-md-4 col-sm-4"><div class="item"><a href="../363/measurement.html"><div class="header" style="height: 35px;"><h3 class="title special" style="margin-top: 0;">Measurement</h3></div><div class="body"><div class="cropper" style="background-image: url('/media/chemistry/images/measurement-and-data/tablet-600649_640.jpg'); height: 10vw;"></div></div></a></div></div></div></div></div></div></div></div><div class="container-fluid shadow-ith"><div class="row frontpage"> <div class="col-md-3" id="left-column"> <p class="visible-xs-block"></p><div class="dropdown user-menu hidden-xs" style="margin-bottom: 20px;"> <button type="button" class="btn btn-default dropdown-toggle" data-toggle="dropdown" style="border-radius: 0; padding: 6px 18px;"> <i class="fa fa-fw fa-user-circle"></i> <small><i class="fa fa-caret-down"></i></small> </button> <ul class="dropdown-menu"> <li class="dropdown-submenu"><a href="#"><i class="fa fa-fw fa-globe"></i> Subjects</a><ul id="user-subjects-menu" class="dropdown-menu"><li></li><li class=""><a href="../../../biology.html">DP Biology</a></li><li class="active"><a href="../../../chemistry.html"><i class="fa fa-caret-right"></i> DP Chemistry</a></li><li class=""><a href="../../../englishalanglit.html">DP English A: Language & Literature</a></li><li class=""><a href="../../../mathsanalysis.html">DP Maths: Analysis & Approaches</a></li><li class=""><a href="../../../mathsapplications.html">DP Maths: Applications & Interpretations SL</a></li><li class=""><a href="../../../physics.html">DP Physics</a></li><li class=""><a href="../../../spanishb.html">DP Spanish B</a></li></ul></li><li class="divider"></li><li><a href="../../../user.html"><i class="fa fa-fw fa-dashboard"></i> Dashboard</a></li><li><a href="../../../user/profile.html"><i class="fa fa-fw fa-cog"></i> My profile</a></li><li><a href="../../../user/messages.html"><i class="fa fa-fw fa-envelope"></i> Messages</a></li> <li class="divider"></li> <li> <a href="../../../index.htm?logout=1"> <i class="fa fa-fw fa-power-off"></i> Log out </a> </li> </ul></div> <div id="side-nav"><h4 class="side-nav-title dropdown"><a href="../362/redox-processes.html" class="dropdown-toggle toplevel-dropdown" data-toggle="dropdown"><i class="fa fa-ellipsis-v"></i></a> <a href="../362/redox-processes.html">Redox Processes</a><ul class="dropdown-menu"><li><a href="../../../chemistry.html" style="padding-left: 5px; border-bottom: solid 1px #ddd"><i class="fa fa-fw fa-home"></i> Home</a></li><li><a href="../3004/free-access-weekend.html"><i class="fa fa-fw fa-caret-right"></i> Free Access Weekend!</a></li><li><a href="../2075/paper-1-exam-questions.html"><i class="fa fa-fw fa-caret-right"></i> Paper 1 Exam Questions</a></li><li><a href="../2124/paper-2-exam-questions.html"><i class="fa fa-fw fa-caret-right"></i> Paper 2 Exam Questions</a></li><li><a href="../1138/start-here.html"><i class="fa fa-fw fa-caret-right"></i> Start Here</a></li><li><a href="../343/stoichiometry.html"><i class="fa fa-fw fa-caret-right"></i> Stoichiometry</a></li><li><a href="../355/atomic-structure.html"><i class="fa fa-fw fa-caret-right"></i> Atomic Structure</a></li><li><a href="../356/periodicity.html"><i class="fa fa-fw fa-caret-right"></i> Periodicity</a></li><li><a href="../357/bonding-and-structure.html"><i class="fa fa-fw fa-caret-right"></i> Bonding and Structure</a></li><li><a href="../358/energetics.html"><i class="fa fa-fw fa-caret-right"></i> Energetics</a></li><li><a href="../359/kinetics.html"><i class="fa fa-fw fa-caret-right"></i> Kinetics</a></li><li><a href="../360/equilibrium.html"><i class="fa fa-fw fa-caret-right"></i> Equilibrium</a></li><li><a href="../361/acids-and-bases.html"><i class="fa fa-fw fa-caret-right"></i> Acids and Bases</a></li><li><a href="../342/organic-chemistry.html"><i class="fa fa-fw fa-caret-right"></i> Organic Chemistry</a></li><li><a href="../363/measurement.html"><i class="fa fa-fw fa-caret-right"></i> Measurement</a></li></ul><div class="pull-right"><a class="sidenav-expand" title="Expand all" href="#"><i class="fa fa-plus-circle"></i></a> <a class="sidenav-compress" title="Compress all" href="#"><i class="fa fa-minus-circle"></i></a></div></h4><ul class="side-nav level-0"><li class=""><label style="padding-left: 0px"><i class="fa fa-fw"></i><a href="../905/oxidation-and-reduction.html">Oxidation and reduction</a></label></li><li class=""><label style="padding-left: 0px"><i class="fa fa-fw"></i><a href="../906/electrochemical-cells-i.html">Electrochemical cells I</a></label></li><li class="expanded parent selected"><label style="padding-left: 0px"><i class="fa fa-fw"></i><a href="electrochemical-cells-ii.html">Electrochemical cells II</a></label></li></ul></div> <button id="show-periodic-table" class="btn btn-default btn-block" style="margin-bottom: 10px"><i class="fa fa-table"></i> Periodic table</button> <div class="hidden-xs hidden-sm"> <button class="btn btn-default btn-block text-xs-center" data-toggle="modal" data-target="#modal-feedback" style="margin-bottom: 10px"><i class="fa fa-send"></i> Feedback</button> </div> </div> <div class="col-md-9" id="main-column"> <h1 class="page_title"> Electrochemical cells II <a href="#" class="mark-page-favorite pull-right" data-pid="907" title="Mark as favorite" onclick="return false;"><i class="fa fa-star-o"></i></a> </h1> <ol class="breadcrumb"> <li><a href="../../../chemistry.html"><i class="fa fa-home"></i></a><i class="fa fa-fw fa-chevron-right divider"></i></li><li><a href="../362/redox-processes.html">Redox Processes</a><i class="fa fa-fw fa-chevron-right divider"></i></li><li><span class="gray">Electrochemical cells II</span></li> <span class="pull-right" style="color: #555" title="Suggested study time: 60 minutes"><i class="fa fa-clock-o"></i> 60'</span> </ol> <article id="main-article"> <p><img alt="" src="../../images/redox-processes/danielcell.jpg" style="width: 160px; height: 148px; float: left;">It is absolutely critical that understanding of the topics <em>oxidation and reduction 9.1</em> and <em>electrochemical cells 9.2 </em>is thorough before beginning on revision of this, more advanced, topic. It is so easy to get lost in this topic, and there is a lot to deal with. However, a really sound grasp of the earlier topics; knowing exactly how voltaic and electrolytic cells operate and where oxidation and reduction occurs will make this much easier, as we can always return to first principles and ask ourselves, <em>Where are the electrons moving?</em></p> <hr class="hidden-separator"> <div class="panel panel-has-colored-body panel-turquoise"> <div class="panel-heading"><a class="expander" href="#"><span class="fa fa-plus"></span></a> <div> <p>Key concepts</p> </div> </div> <div class="panel-body"> <div> <div class="panel-body"> <div> <p>Ensure you are confident using the terms below and learn the asterisked* definitions</p> <p>Electrochemical series, <strong>Standard electrode potential*</strong>, Cell potential, <strong>Standard hydrogen electrode (SHE)*</strong>, Faraday constant, Electroplating, Absolute charge</p> <div class="tib-flashcard"><a class="show-flashcards btn btn-success btn-xs-block btn-block " data-levels="3" data-mode="Normal" data-topics="645" data-subject-id="7" data-n-flashcards="7" style="text-align:center">Show flashcards</a></div><hr> <p> </p> <div class="panel panel-blue"> <div class="panel-heading"><a class="expander" href="#"><span class="fa fa-plus"></span></a> <div> <p>Electrochemical cells</p> </div> </div> <div class="panel-body"> <div> <p>A reminder from <em>electrochemical cells</em> <em>9.1</em> that understanding the redox processes that take place in voltaic and electrolytic cells is a key concept.</p> <div class="video-embed vimeo"><iframe allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen="" mozallowfullscreen="" webkitallowfullscreen="" height="420" width="100%" src="https://player.vimeo.com/video/447161708"></iframe></div> <p> </p> </div> </div> <div class="panel-footer"> <div> <p> </p> </div> </div> </div> </div> </div> </div> </div> <div class="panel-footer"> <div> </div> </div> </div> <div class="panel panel-yellow panel-has-colored-body"> <div class="panel-heading"><a class="expander" href="#"><span class="fa fa-plus"></span></a> <div> <p>Essentials</p> </div> </div> <div class="panel-body"> <div> <p> The revision cards contain all of the essential content:</p> <div id="carousel-209" class="dynamic-gallery carousel slide" data-id="209"><div class="carousel-inner" role="listbox"><div class="item active"><a class="fancy" href="../../../std-galleries/7-209/screenshot-2020-08-16-at-130243.png" data-fancybox="gallery-209" title="" data-caption=""><img alt="" src="../../../std-galleries/7-209/screenshot-2020-08-16-at-130243.png"></a></div><div class="item "><a class="fancy" href="../../../std-galleries/7-209/screenshot-2020-08-16-at-130301.png" data-fancybox="gallery-209" title="" data-caption=""><img alt="" src="../../../std-galleries/7-209/screenshot-2020-08-16-at-130301.png"></a></div><div class="item "><a class="fancy" href="../../../std-galleries/7-209/screenshot-2020-08-16-at-130322.png" data-fancybox="gallery-209" title="" data-caption=""><img alt="" src="../../../std-galleries/7-209/screenshot-2020-08-16-at-130322.png"></a></div><div class="item "><a class="fancy" href="../../../std-galleries/7-209/screenshot-2020-08-16-at-130339.png" data-fancybox="gallery-209" title="" data-caption=""><img alt="" src="../../../std-galleries/7-209/screenshot-2020-08-16-at-130339.png"></a></div><div class="item "><a class="fancy" href="../../../std-galleries/7-209/screenshot-2020-08-16-at-130354.png" data-fancybox="gallery-209" title="" data-caption=""><img alt="" src="../../../std-galleries/7-209/screenshot-2020-08-16-at-130354.png"></a></div><div class="item "><a class="fancy" href="../../../std-galleries/7-209/screenshot-2020-08-16-at-130413.png" data-fancybox="gallery-209" title="" data-caption=""><img alt="" src="../../../std-galleries/7-209/screenshot-2020-08-16-at-130413.png"></a></div><div class="item "><a class="fancy" href="../../../std-galleries/7-209/screenshot-2020-08-16-at-130427.png" data-fancybox="gallery-209" title="" data-caption=""><img alt="" src="../../../std-galleries/7-209/screenshot-2020-08-16-at-130427.png"></a></div><div class="item "><a class="fancy" href="../../../std-galleries/7-209/screenshot-2020-08-16-at-130442.png" data-fancybox="gallery-209" title="" data-caption=""><img alt="" src="../../../std-galleries/7-209/screenshot-2020-08-16-at-130442.png"></a></div></div><a class="left carousel-control" href="#carousel-209" role="button" data-slide="prev"><i class="fa fa-fw fa-chevron-left"></i></a><a class="right carousel-control" href="#carousel-209" role="button" data-slide="next"><i class="fa fa-fw fa-chevron-right"></i></a></div><ol class="std-carousel-indicators"><li data-index="0"><img title="Click to view" src="../../../std-galleries/7-209/screenshot-2020-08-16-at-130243-thumb128.jpg"><li><li data-index="1"><img title="Click to view" src="../../../std-galleries/7-209/screenshot-2020-08-16-at-130301-thumb128.jpg"><li><li data-index="2"><img title="Click to view" src="../../../std-galleries/7-209/screenshot-2020-08-16-at-130322-thumb128.jpg"><li><li data-index="3"><img title="Click to view" src="../../../std-galleries/7-209/screenshot-2020-08-16-at-130339-thumb128.jpg"><li><li data-index="4"><img title="Click to view" src="../../../std-galleries/7-209/screenshot-2020-08-16-at-130354-thumb128.jpg"><li><li data-index="5"><img title="Click to view" src="../../../std-galleries/7-209/screenshot-2020-08-16-at-130413-thumb128.jpg"><li><li data-index="6"><img title="Click to view" src="../../../std-galleries/7-209/screenshot-2020-08-16-at-130427-thumb128.jpg"><li><li data-index="7"><img title="Click to view" src="../../../std-galleries/7-209/screenshot-2020-08-16-at-130442-thumb128.jpg"><li></li></ol> </div> </div> <div class="panel-footer"> <div> </div> </div> </div> <div class="panel panel-has-colored-body panel-green"> <div class="panel-heading"><a class="expander" href="#"><span class="fa fa-plus"></span></a> <div> <p>Test yourself</p> </div> </div> <div class="panel-body"> <div> <div class="panel-body"> <div> <div class="tib-quiz" data-stats="7-538-907"><div class="label label-default q-number">1</div><div class="exercise shadow-bottom"><div class="q-question"><p>Which of the following statements about a voltaic cell consisting of the zinc and iron half-cells below are correct?</p><p>Zn<sup>2+</sup><sub>(aq)</sub> + 2e<sup>–</sup> ⇌ Zn<sub>(s) </sub> E<sup><s>o</s></sup> = –0.76 V</p><p>Fe<sup>3+</sup><sub>(aq)</sub> + e<sup>–</sup> ⇌ Fe<sup>2+</sup><sub>(aq) </sub> E<sup><s>o</s> </sup>= +0.77 V</p><p><strong>1: </strong>Electrons flow from the iron half-cell to the zinc half-cell.</p><p><strong>2: </strong>The cell potential E<sup><s>o</s></sup><sub>cell</sub> = +1.53 V</p><p><strong>3: </strong>Negative ions travel across the salt bridge from the iron half-cell to the zinc half-cell.</p></div><div class="q-answer"><p><label class="radio"> <input class="c" type="radio"> <span>2 and 3 only</span></label> </p><p><label class="radio"> <input type="radio"> <span>1 and 2 only</span></label> </p><p><label class="radio"> <input type="radio"> <span>1, 2 and 3</span></label> </p><p><label class="radio"> <input type="radio"> <span>1 and 3 only</span></label> </p></div><div class="q-explanation"><p>In a voltaic cell the redox reaction generates the charges on the electrodes and causes the current to flow. The half-cell highest in the electrochemical series (most negative) loses electrons (oxidation) causing the electrode to be negative, and the half-cell lowest in the electrochemical series (most positive) gains electrons (reduction) causing the electrode to be positive.</p><p>Zinc half-cell is more negative than the iron half-cell (Electrochemical series in the data book) so the zinc half-cell will lose electrons (oxidation) and the iron half-cell will gain electrons (reduction); <strong>electrons will flow from the zinc to iron</strong>.</p><p>E<sup><s>o</s></sup>cell = E<sup><s>o</s></sup>cathode – E<sup><s>o</s></sup>anode = +0.77 – –0.76 = <strong>+1.53 V</strong></p><p>As electrons are flowing from zinc to iron, the charge will be equalised by n<strong>egative ions flowing across the salt bridge from the iron to the zinc </strong>half-cell.</p><p>Thus <strong>2 and 3 only </strong>is the correct answer.</p></div><div class="actions"><span class="score" data-score="0"></span><button class="btn btn-default btn-sm btn-xs-block text-xs-center check"><i class="fa fa-check-square-o"></i> Check</button></div></div><div class="label label-default q-number">2</div><div class="exercise shadow-bottom"><div class="q-question"><p>What is the overall cell reaction and cell potential for a voltaic cell consisting of the nickel and copper half-cells below?</p><p>Ni<sup>2+</sup><sub>(aq)</sub> + 2e<sup>–</sup> ⇌ Ni<sub>(s) </sub> E<sup><s>o</s></sup> = –0.26 V</p><p>Cu<sup>2+</sup><sub>(aq)</sub> + 2e<sup>–</sup> ⇌ Cu<sub>(s) </sub> E<sup><s>o</s></sup> = +0.34 V</p></div><div class="q-answer"><p><label class="radio"> <input type="radio"> <span>Cu<sup>2+</sup><sub>(aq)</sub> + Ni<sub>(s)</sub> ⇌ Ni<sup>2+</sup><sub>(aq)</sub> + Cu<sub>(s)</sub> E<sup><s>o</s></sup>cell = +0.08 V</span></label> </p><p><label class="radio"> <input type="radio"> <span>Ni<sup>2+</sup><sub>(aq)</sub> + Cu<sub>(s)</sub> ⇌ Cu<sup>2+</sup><sub>(aq)</sub> + Ni<sub>(s)</sub> E<sup><s>o</s></sup>cell = +0.08 V</span></label> </p><p><label class="radio"> <input class="c" type="radio"> <span>Cu<sup>2+</sup><sub>(aq)</sub> + Ni<sub>(s)</sub> ⇌ Ni<sup>2+</sup><sub>(aq)</sub> + Cu<sub>(s)</sub> E<sup><s>o</s></sup>cell = +0.60 V</span></label> </p><p><label class="radio"> <input type="radio"> <span>Ni<sup>2+</sup><sub>(aq)</sub> + Cu<sub>(s)</sub> ⇌ Cu<sup>2+</sup><sub>(aq)</sub> + Ni<sub>(s)</sub> E<sup><s>o</s></sup>cell = +0.60 V</span></label> </p></div><div class="q-explanation"><p>In a voltaic cell the half-cell highest in the electrochemical series (most negative) loses electrons (oxidation) and the half-cell lowest in the electrochemical series (most positive) gains electrons (reduction).</p><p>Nickel half-cell is more negative than the copper half-cell (Electrochemical series in the data book) so the nickel half-cell will lose electrons (oxidation) and the copper half-cell will gain electrons (reduction)<strong>:</strong></p><p>Ni<sub>(s)</sub> → Ni<sup>2+</sup><sub>(aq)</sub> + 2e<sup>–</sup> and Cu<sup>2+</sup><sub>(aq)</sub> + 2e<sup>–</sup> → Cu<sub>(s)</sub></p><p>The number of electrons lost and gained is the same so the half-equations combined:</p><p>Cu<sup>2+</sup><sub>(aq)</sub> + Ni<sub>(s)</sub> ⇌ Ni<sup>2+</sup><sub>(aq)</sub> + Cu<sub>(s)</sub></p><p>E<sup><s>o</s></sup>cell = E<sup><s>o</s></sup>cathode – E<sup><s>o</s></sup>anode = +0.34 – –0.26 = +0.60 V</p><p>Thus <strong>Cu<sup>2+</sup><sub>(aq)</sub> + Ni<sub>(s)</sub> ⇌ Ni<sup>2+</sup><sub>(aq)</sub> + Cu<sub>(s)</sub> E<sup><s>o</s></sup>cell = +0.60 V</strong> is the correct answer.</p></div><div class="actions"><span class="score" data-score="0"></span><button class="btn btn-default btn-sm btn-xs-block text-xs-center check"><i class="fa fa-check-square-o"></i> Check</button></div></div><div class="label label-default q-number">3</div><div class="exercise shadow-bottom"><div class="q-question"><p>What is the overall cell reaction and cell potential for a voltaic cell consisting of the nickel and aluminium half-cells below?</p><p>Ni<sup>2+</sup><sub>(aq)</sub> + 2e<sup>–</sup> ⇌ Ni<sub>(s) </sub> E<sup><s>o</s></sup> = –0.26 V</p><p>Al<sup>3+</sup><sub>(aq)</sub> + 3e<sup>–</sup> ⇌ Al<sub>(s) </sub> E<sup><s>o</s></sup> = –1.66 V</p></div><div class="q-answer"><p><label class="radio"> <input type="radio"> <span>2Al<sup>3+</sup><sub>(aq)</sub> + 3Ni<sub>(s) </sub>⇌ 3Ni<sup>2+</sup><sub>(aq)</sub> + 2Al<sub>(s)</sub> E<sup><s>o</s></sup>cell = –1.40 V</span></label> </p><p><label class="radio"> <input type="radio"> <span>2Al<sup>3+</sup><sub>(aq)</sub> + 3Ni<sub>(s) </sub>⇌ 3Ni<sup>2+</sup><sub>(aq)</sub> + 2Al<sub>(s)</sub> E<sup><s>o</s></sup>cell = –1.92 V</span></label> </p><p><label class="radio"> <input class="c" type="radio"> <span>3Ni<sup>2+</sup><sub>(aq)</sub> + 2Al<sub>(s)</sub> ⇌ 2Al<sup>3+</sup><sub>(aq)</sub> + 3Ni<sub>(s)</sub> E<sup><s>o</s></sup>cell = +1.40 V</span></label> </p><p><label class="radio"> <input type="radio"> <span>Ni<sup>2+</sup><sub>(aq)</sub> + Al<sub>(s)</sub> ⇌ Al<sup>3+</sup><sub>(aq)</sub> + Ni<sub>(s)</sub> E<sup><s>o</s></sup>cell = +1.40 V</span></label> </p></div><div class="q-explanation"><p>In a voltaic cell the half-cell highest in the electrochemical series (most negative) loses electrons (oxidation) and the half-cell lowest in the electrochemical series (most positive) gains electrons (reduction).</p><p>Aluminium half-cell is more negative than the nickel half-cell (Electrochemical series in the data book) so the aluminium half-cell will lose electrons (oxidation) and the nickel half-cell will gain electrons (reduction)<strong>:</strong></p><p>Al<sub>(s)</sub> → Al<sup>3+</sup><sub>(aq)</sub> + 3e<sup>–</sup> and Ni<sup>2+</sup><sub>(aq)</sub> + 2e<sup>–</sup> → Ni<sub>(s)</sub></p><p>The number of electrons lost and gained in each half-cell must be equalised when the half-equations combine (Al × 2, Ni × 3):</p><p>3Ni<sup>2+</sup><sub>(aq)</sub> + 2Al<sub>(s)</sub> ⇌ 2Al<sup>3+</sup><sub>(aq)</sub> + 3Ni<sub>(s)</sub></p><p>E<sup><s>o</s></sup>cell = E<sup><s>o</s></sup>cathode – E<sup><s>o</s></sup>anode = –0.26 – –1.66 = +1.40 V</p><p>Note that the E<sup><s>o</s></sup> values are independent of the multiplication to equal out the number of electrons.</p><p>Thus <strong>3Ni<sup>2+</sup><sub>(aq)</sub> + 2Al<sub>(s)</sub> ⇌ 2Al<sup>3+</sup><sub>(aq)</sub> + 3Ni<sub>(s)</sub> E<sup><s>o</s></sup>cell = +1.40V</strong> is the correct answer.</p></div><div class="actions"><span class="score" data-score="0"></span><button class="btn btn-default btn-sm btn-xs-block text-xs-center check"><i class="fa fa-check-square-o"></i> Check</button></div></div><div class="label label-default q-number">4</div><div class="exercise shadow-bottom"><div class="q-question"><p>Which of the following statements about the standard hydrogen electrode (SHE) are correct?</p><p><strong>1: </strong>The electrode is made of inert platinum.</p><p><strong>2: </strong>Hydrogen gas is fed onto the electrode at 100kPa.</p><p><strong>3: </strong>The electrode is immersed in hydrochloric acid (1 mol dm<sup>−3</sup>) at 298K.</p></div><div class="q-answer"><p><label class="radio"> <input type="radio"> <span>2 and 3 only</span></label> </p><p><label class="radio"> <input class="c" type="radio"> <span>1, 2 and 3</span></label> </p><p><label class="radio"> <input type="radio"> <span>1 and 2 only</span></label> </p><p><label class="radio"> <input type="radio"> <span>1 and 3 only</span></label> </p></div><div class="q-explanation"><p>Electrode potentials are measured against the SHE; standard hydrogen electrode.</p><p>The SHE consists of a feed of hydrogen gas at 100 kPa onto an inert Pt electrode in 1 mol dm<sup>–3</sup> hydrochloric acid all at 298 K.</p><p>The platinum electrode is coated with platinum black; finely powdered platinum to give a high surface area for the reaction to occur on: H<sup>+</sup><sub>(aq)</sub> + e<sup>–</sup> ⇌ ½H<sub>2(g)</sub> E<sup><s>o</s></sup> = 0.00 V</p><p>Thus <strong>1, 2 and 3 </strong>is the correct answer.</p></div><div class="actions"><span class="score" data-score="0"></span><button class="btn btn-default btn-sm btn-xs-block text-xs-center check"><i class="fa fa-check-square-o"></i> Check</button></div></div><div class="label label-default q-number">5</div><div class="exercise shadow-bottom"><div class="q-question"><p>Which of the following half-cells <strong>does not </strong>require a platinum electrode?</p></div><div class="q-answer"><p><label class="radio"> <input type="radio"> <span>Cu<sup>2+</sup><sub>(aq)</sub> + e<sup>–</sup> ⇌ Cu<sup>+</sup><sub>(aq)</sub></span></label> </p><p><label class="radio"> <input class="c" type="radio"> <span>Cu<sup>2+</sup><sub>(aq)</sub> + 2e<sup>–</sup> ⇌ Cu<sub>(s)</sub></span></label> </p><p><label class="radio"> <input type="radio"> <span>H<sup>+</sup><sub>(aq)</sub> + e<sup>–</sup> ⇌ ½H<sub>2(g)</sub></span></label> </p><p><label class="radio"> <input type="radio"> <span> ½Cl<sub>2(g)</sub> + e<sup>–</sup> ⇌ Cl<sup>−</sup><sub>(aq)</sub></span></label> </p></div><div class="q-explanation"><p>An inert platinum electrode is needed for all gaseous electrodes (e.g. chlorine and hydrogen) and for half-cells involving only aqueous ions (e.g. Cu<sup>2+</sup><sub>(aq)</sub> + e<sup>–</sup> ⇌ Cu<sup>+</sup><sub>(aq)</sub>).</p><p>The copper half-cell <strong>Cu<sup>2+</sup><sub>(aq)</sub> + 2e<sup>–</sup> ⇌ Cu<sub>(s)</sub> </strong>requires a copper electrode and is therefore the correct answer.</p></div><div class="actions"><span class="score" data-score="0"></span><button class="btn btn-default btn-sm btn-xs-block text-xs-center check"><i class="fa fa-check-square-o"></i> Check</button></div></div><div class="label label-default q-number">6</div><div class="exercise shadow-bottom"><div class="q-question"><p><em>Calculator question: </em>What is the value of ΔG<sup><s>o</s></sup> under standard conditions when calculated for the cell reaction in a voltaic cell consisting of the two half-cells below (in kJ to 3 sig figs)?</p><p>(using ΔG<sup><s>o</s></sup>= –nFE<sup><s>o</s></sup><sub>cell</sub> in data book)</p><p>Fe<sup>2+</sup><sub>(aq)</sub> + 2e<sup>–</sup> ⇌ Fe<sub>(s) </sub> E<sup><s>o</s></sup> = –0.45 V</p><p>Cu<sup>2+</sup><sub>(aq)</sub> + 2e<sup>–</sup> ⇌ Cu<sub>(s) </sub> E<sup><s>o</s></sup> = +0.34 V</p></div><div class="q-answer"><p><label class="radio"> <input class="c" type="radio"> <span>–152 </span></label> </p><p><label class="radio"> <input type="radio"> <span>+76.2</span></label> </p><p><label class="radio"> <input type="radio"> <span>–76.2</span></label> </p><p><label class="radio"> <input type="radio"> <span>+152</span></label> </p></div><div class="q-explanation"><p>Iron(II) half-cell is more negative than the copper half-cell (Electrochemical series in the data book) so the iron half-cell will lose electrons (oxidation) and the copper half-cell will gain electrons (reduction)<strong>:</strong></p><p>Fe<sub>(s)</sub> → Fe<sup>2+</sup><sub>(aq)</sub> + 2e<sup>–</sup> and Cu<sup>2+</sup><sub>(aq)</sub> + 2e<sup>–</sup> → Cu<sub>(s)</sub></p><p>The number of electrons lost and gained is the same (<strong>that is two electrons</strong>) so the half-equations combined:</p><p>Cu<sup>2+</sup><sub>(aq)</sub> + Fe<sub>(s)</sub> ⇌ Fe<sup>2+</sup><sub>(aq)</sub> + Cu<sub>(s)</sub></p><p>E<sup><s>o</s></sup>cell = E<sup><s>o</s></sup>cathode – E<sup><s>o</s></sup>anode = +0.34 – –0.45 = +0.79 V</p><p>ΔG<sup><s>o</s></sup> = –nFE<sup><s>o</s></sup><sub>cell </sub> = – (<strong>2 mol</strong> × 96500 C mol<sup>–1</sup> × +0.79 V) = – 152470 J = –152 kJ (3 sig figs)</p><p><strong>Incorrect answers</strong></p><p>–76.2 uses 1 mol of electrons instead of 2</p><p>+152 uses –0.79 V instead of +0.79 V (or emits to use the –ve sign in the equation)</p><p>+76.2 uses 1 mol of electrons instead of 2 <strong>and</strong> uses –0.79 V instead of +0.79 V (or emits to use the –ve sign in the equation)</p></div><div class="actions"><span class="score" data-score="0"></span><button class="btn btn-default btn-sm btn-xs-block text-xs-center check"><i class="fa fa-check-square-o"></i> Check</button></div></div><div class="label label-default q-number">7</div><div class="exercise shadow-bottom"><div class="q-question"><p>Which half-equations occur at the negative and positive electrodes respectively when aqueous copper chloride solution is electrolysed using copper electrodes?</p></div><div class="q-answer"><p><label class="radio"> <input class="c" type="radio"> <span>negative: Cu<sup>2+</sup><sub>(aq)</sub> + 2e<sup>–</sup> → Cu<sub>(s)</sub> positive: Cu<sub>(s)</sub> → Cu<sup>2+</sup><sub>(aq)</sub> + 2e<sup>–</sup> </span></label></p><p><label class="radio"> <input type="radio"> <span>negative: Cu<sup>2+</sup><sub>(aq)</sub> + 2e<sup>–</sup> → Cu<sub>(s)</sub> positive: Cl<sup>–</sup><sub>(aq)</sub> → ½Cl<sub>2(g)</sub> + e<sup>–</sup></span></label> </p><p><label class="radio"> <input type="radio"> <span>negative: Cu<sup>2+</sup><sub>(aq)</sub> + 2e<sup>–</sup> → Cu<sub>(s)</sub> positive: H<sub>2</sub>O<sub>(l)</sub> → ½O<sub>2</sub> + 2H<sup>+</sup><sub>(aq)</sub> + 2e<sup>–</sup></span></label> </p><p><label class="radio"> <input type="radio"> <span>negative H<sub>2</sub>O<sub>(l)</sub> + e<sup>–</sup> → ½H<sub>2(g)</sub> + OH<sup>–</sup><sub>(aq)</sub> positive: H<sub>2</sub>O<sub>(l)</sub> → ½O<sub>2</sub> + 2H<sup>+</sup><sub>(aq)</sub> + 2e<sup>–</sup> </span></label> </p></div><div class="q-explanation"><p>The species discharged at the negative electrode, gaining e<sup>–</sup> will be lower (less –ve) in the electrochemical series; copper is lower than water so copper ions are discharged.</p><p>Normally the species discharged at the positive electrode, losing e<sup>–</sup>, will be higher (less +ve) in the electrochemical series. Note! Exception: Chloride ions (½Cl<sub>2(g)</sub> + e<sup>–</sup> ⇌ Cl<sup>–</sup><sub>(aq) </sub>E<sup><s>o</s></sup> = +1.36 V) are preferentially discharged over water (½O<sub>2(g)</sub> + 2H<sup>+</sup><sub>(aq)</sub> + 2e<sup>–</sup> ⇌ H<sub>2</sub>O<sub>(l)</sub> E<sup><s>o</s></sup> = +1.23 V) at the positive electrode despite their E<sup><s>o</s></sup> values (this is a kinetic effect that needs remembering).</p><p>However, if a copper electrode is used instead of an inert electrode, copper from the electrode will lose electrons preferentially over chloride ions or water (Cu<sup>2+</sup><sub>(aq)</sub> + 2e<sup>–</sup> ⇌ Cu<sub>(s)</sub> E<sup><s>o</s></sup> = +0.34 V) because its E<sup><s>o</s></sup> is higher in the electrochemical series.</p><p>Thus <strong>negative: Cu<sup>2+</sup><sub>(aq)</sub> + 2e<sup>–</sup> → Cu<sub>(s)</sub> positive: Cu<sub>(s)</sub> → Cu<sup>2+</sup><sub>(aq)</sub> + 2e<sup>–</sup> </strong>is the correct answer.</p></div><div class="actions"><span class="score" data-score="0"></span><button class="btn btn-default btn-sm btn-xs-block text-xs-center check"><i class="fa fa-check-square-o"></i> Check</button></div></div><div class="label label-default q-number">8</div><div class="exercise shadow-bottom"><div class="q-question"><p>What is produced at the negative and positive electrodes respectively when aqueous copper(II) chloride solution is electrolysed using inert electrodes?</p></div><div class="q-answer"><p><label class="radio"> <input type="radio"> <span>hydrogen and oxygen</span></label> </p><p><label class="radio"> <input class="c" type="radio"> <span>copper and chlorine</span></label> </p><p><label class="radio"> <input type="radio"> <span>copper and oxygen</span></label> </p><p><label class="radio"> <input type="radio"> <span>hydrogen and chlorine</span></label> </p></div><div class="q-explanation"><p>The species discharged at the negative electrode, gaining e<sup>–</sup> will be lower (less –ve) in the electrochemical series; copper is lower than water so copper ions are discharged.</p><p>The species discharged at the positive electrode, losing e<sup>–</sup>, will be higher (less +ve) in the electrochemical series. Note! Exception: Chloride ions (½Cl<sub>2(g)</sub> + e<sup>–</sup> ⇌ Cl<sup>–</sup><sub>(aq) </sub>E<sup><s>o</s></sup> = +1.36 V) are preferentially discharged over water (½O<sub>2(g)</sub> + 2H<sup>+</sup><sub>(aq)</sub> + 2e<sup>–</sup> ⇌ H<sub>2</sub>O<sub>(l)</sub> E<sup><s>o</s></sup> = +1.23 V) at the positive electrode despite their E<sup><s>o</s></sup> values (this is a kinetic effect that needs remembering).</p><p>Thus <strong>copper and chlorine</strong> is the correct answer.</p></div><div class="actions"><span class="score" data-score="0"></span><button class="btn btn-default btn-sm btn-xs-block text-xs-center check"><i class="fa fa-check-square-o"></i> Check</button></div></div><div class="label label-default q-number">9</div><div class="exercise shadow-bottom"><div class="q-question"><p><em>Calculator question: </em>What mass of zinc (in g to 3 sf) is deposited at the cathode if zinc sulfate solution is electrolysed for 30.0 minutes at a current of 5.00A?</p></div><div class="q-answer"><p><label class="radio"> <input class="c" type="radio"> <span>3.05</span></label> </p><p><label class="radio"> <input type="radio"> <span>0.0508</span></label> </p><p><label class="radio"> <input type="radio"> <span>0.102</span></label> </p><p><label class="radio"> <input type="radio"> <span>6.10</span></label> </p></div><div class="q-explanation"><p>Charge = current × time = 5.0 × (30.0 × 60) = 9000C</p><p>Moles of electrons passed through circuit = charge/Faraday = 9000/96500 = 0.0932642</p><p>Half equation: Zn<sup>2+</sup><sub>(aq) </sub>+ 2e<sup>–</sup> → Zn(s) so mole ratio of electrons to zinc atoms is 2:1,</p><p>Therefore mass of zinc = moles × Ar = 0.0932642/2 × 65.38 = 3.0488083 = <strong>3.05g</strong> (3sf)</p><p>Therefore <strong>3.05</strong> is the correct answer.</p><p><strong>Incorrect answers</strong></p><p>6.10 uses a 1:1 mole ratio for electrons to atoms instead of 2:1</p><p>0.0508 uses 150C of charge (forgetting to multiply minutes by 60 to get seconds)</p><p>0.102 uses 150C of charge (forgetting to multiply minutes by 60 to get seconds) <strong>and</strong> uses a 1:1 mole ratio for electrons to atoms instead of 2:1</p></div><div class="actions"><span class="score" data-score="0"></span><button class="btn btn-default btn-sm btn-xs-block text-xs-center check"><i class="fa fa-check-square-o"></i> Check</button></div></div><div class="label label-default q-number">10</div><div class="exercise shadow-bottom"><div class="q-question"><p><em>Calculator question: </em>Two cells are electrolysed in series. What mass of calcium (in g to 3 sf) is deposited at the cathode in ‘cell A’, if 1.62g aluminium is deposited at the cathode in ‘cell B’?</p></div><div class="q-answer"><p><label class="radio"> <input type="radio"> <span>2.41</span></label> </p><p><label class="radio"> <input class="c" type="radio"> <span>3.61</span></label> </p><p><label class="radio"> <input type="radio"> <span>4.81</span></label> </p><p><label class="radio"> <input type="radio"> <span>1.60</span></label> </p></div><div class="q-explanation"><p>Moles of aluminium = mass/Ar = 1.62/26.98 = 0.0600444 mol</p><p>Half equations: Al<sup>3+</sup><sub>(aq)</sub> + <u>3e</u><sup>–</sup> → Al<sub>(s) </sub> and Ca<sup>2+</sup><sub>(aq)</sub> + <u>2e</u><sup>–</sup> → Ca<sub>(s)</sub> so ratio of<strong> moles of electrons</strong> for aluminium to <strong>moles of electrons</strong> for calcium is 3:2.</p><p>This means that the ratio of moles of aluminium:calcium will be 2:3 (since the same number of electrons will pass through the circuit, but that will give more calcium atoms as only two electrons are needed for each atom, rather than 3 for aluminium).</p><p>Moles of calcium = 0.0600444 × 3/2 = 0.0900666</p><p>Mass of calcium = moles × Ar = 0.0900666 × 40.08 = 3.6098693 = 3.61g (3sf)</p><p>Therefore <strong>3.61</strong> is the correct answer.</p><p><strong>Incorrect answers</strong></p><p>1.60 uses a 3:2 mole ratio for moles of aluminium:calcium instead of 2:3</p><p>2.41 uses a 1:1 mole ratio for moles of aluminium:calcium instead of 2:3</p><p>4.81 uses a 1:2 mole ratio for moles of aluminium:calcium instead of 2:3</p></div><div class="actions"><span class="score" data-score="0"></span><button class="btn btn-default btn-sm btn-xs-block text-xs-center check"><i class="fa fa-check-square-o"></i> Check</button></div></div><div class="totals"><span class="score"></span><button class="btn btn-success btn-block text-center check-total"><i class="fa fa-check-square-o"></i> Check</button></div></div><hr> </div> </div> </div> </div> <div class="panel-footer"> <div> </div> </div> </div> <div class="panel panel-has-colored-body panel-default"> <div class="panel-heading"><a class="expander" href="#"><span class="fa fa-plus"></span></a> <div> <p>Exam-style questions</p> </div> </div> <div class="panel-body"> <div> <h4>Paper 1</h4> <h5>Core (SL&HL): <a href="../2724/redox-core-sl-and-hl-paper-1-questions.html" title="Redox core (SL and HL) paper 1 questions">Redox core (SL and HL) paper 1 questions</a></h5> <h5>AHL (HL only): <a href="../2731/redox-ahl-hl-only-paper-1-questions.html" title="Redox AHL (HL only) paper 1 questions">Redox AHL (HL only) paper 1 questions</a></h5> <h4>Paper 2</h4> <h5>Core (SL&HL): <a href="../2728/redox-core-sl-hl-paper-2-questions.html" title="Redox core (SL & HL) paper 2 questions">Redox core (SL & HL) paper 2 questions</a></h5> <h5>AHL (HL only): <a href="../2730/redox-ahl-hl-only-paper-2-questions.html" title="Redox AHL (HL only) paper 2 questions">Redox AHL (HL only) paper 2 questions</a></h5> </div> </div> <div class="panel-footer"> <div> </div> </div> </div> <div class="page-container panel-self-assessment" data-id="907"> <div class="panel-heading">MY PROGRESS</div> <div class="panel-body understanding-rate"> <div class="msg"></div> <label class="label-lg">Self-assessment</label><p>How much of <strong>Electrochemical cells II</strong> have you understood?</p><div class="slider-container text-center"><div id="self-assessment-slider" class="sib-slider self-assessment " data-value="1" data-percentage=""></div></div> <label class="label-lg">My notes</label> <textarea name="page-notes" class="form-control" rows="3" placeholder="Write your notes here..."></textarea> </div> <div class="panel-footer text-xs-center"> <span id="last-edited" class="mb-xs-3"> </span> <div class="actions mt-xs-3"> <button id="save-my-progress" type="button" class="btn btn-sm btn-primary text-center btn-xs-block"> <i class="fa fa-fw fa-floppy-o"></i> Save </button> </div> </div></div> <div id="modal-feedback" class="modal fade" tabindex="-1" role="dialog"> <div class="modal-dialog" role="document"> <div class="modal-content"> <div class="modal-header"> <h4 class="modal-title">Feedback</h4> <button type="button" class="close hidden-xs hidden-sm" data-dismiss="modal" aria-label="Close"> <span aria-hidden="true">×</span> </button> </div> <div class="modal-body"> <div class="errors"></div> <p><strong>Which of the following best describes your feedback?</strong></p> <form method="post" style="overflow: hidden"> <div class="form-group"> <div class="radio"><label style="color: #121212;"><input type="radio" name="feedback-type" value="Recommendation"> Recommend</label></div><div class="radio"><label style="color: #121212;"><input type="radio" name="feedback-type" value="Problem"> Report a problem</label></div><div class="radio"><label style="color: #121212;"><input type="radio" name="feedback-type" value="Improvement"> Suggest an improvement</label></div><div class="radio"><label style="color: #121212;"><input type="radio" name="feedback-type" value="Other"> Other</label></div> </div> <hr> <div class="row"> <div class="col-md-6"> <div class="form-group"> <label for="feedback-name">Name</label> <input type="text" class="form-control" name="feedback-name" placeholder="Name" value=" "> </div> </div> <div class="col-md-6"> <div class="form-group"> <label for="feedback-email">Email address</label> <input type="email" class="form-control" name="feedback-email" placeholder="Email" value="@airmail.cc"> </div> </div> </div> <div class="form-group"> <label for="feedback-comments">Comments</label> <textarea class="form-control" name="feedback-comments" style="resize: vertical;"></textarea> </div> <input type="hidden" name="feedback-ticket" value="082b9c9c4ae3624d"> <input type="hidden" name="feedback-url" value="https://studyib.net/chemistry/page/907/electrochemical-cells-ii"> <input type="hidden" name="feedback-subject" value="7"> <input type="hidden" name="feedback-subject-name" value="Chemistry"> <div class="pull-left"> </div> </form> </div> <div class="modal-footer"> <button type="button" class="btn btn-primary btn-xs-block feedback-submit mb-xs-3 pull-right"> <i class="fa fa-send"></i> Send </button> <button type="button" class="btn btn-default btn-xs-block m-xs-0 pull-left" data-dismiss="modal"> Close </button> </div> </div> </div></div> <style type="text/css" media="screen">/* Important part */
.modal-dialog{ overflow-y: initial !important
}
.modal-body{ overflow-x: auto; overflow-y: auto;
}</style><div id="modal-periodic-table" class="modal fade" tabindex="-1" role="dialog"> <div class="modal-dialog modal-lg" role="document" style="width: 90vw;"> <div class="modal-content"> <div class="modal-header"> <h4 class="modal-title">Periodic table</h4> <button type="button" class="close" data-dismiss="modal" aria-label="Close"> <span aria-hidden="true">×</span> </button> </div> <div class="modal-body"> <img src="../../../img/periodic-table/periodic-table-2020.png" style="max-width: 1400px; height: auto"> </div> <div class="modal-footer"> <button type="button" class="btn btn-default btn-xs-block m-xs-0 pull-right" data-dismiss="modal" aria-hidden="true"> Close </button> </div> </div> </div></div> <div id="fc-viewer" class="modal fade modal-flashcard" tabindex="-1" role="dialog"><div class="modal-dialog" role="document"><div class="modal-content"><div class="modal-header" style="background-color: #fafafa;"><div class="row" style="width: 100%;"><div class="col-md-12 tags-heading"><div style="display: flex; justify-content: space-between; align-items: center;"><p id="fc-viewer-info" style="width: 80%;"></p><button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">×</span></button></div></div></div></div><div id="flashcard-body" class="modal-body"><div class="row" style="margin: 0;"><div class="col-md-8 fc-viewer-main"><div class="fc-viewer-inner"><div id="fc-viewer-main-front"><div class="fc-viewer-content"></div><span class="mark-favorite" style="position: absolute; top: 10px; right: 10px; font-size: 22px;"><i class="fa fa-lg fa-star-o"></i></span><span id="issue-report" class="issue-report hidden-xs hidden-sm" title="Report a problem"><i class="fa fa-fw fa-lg fa-exclamation-circle" style="font-size: 1.5em;"></i> </span> </div><div id="fc-viewer-main-back" class="reverse-flashcard green-bg"><div class="fc-viewer-content"></div><span class="mark-favorite" style="position: absolute; top: 10px; right: 10px; font-size: 22px;"><i class="fa fa-lg fa-star-o"></i></span></div></div></div><div class="col-md-4 fc-viewer-controls"><div class="fc-viewer-controls-middle"> <div class="fc-viewer-controls-middle-inner fc-back"><div class="fc-viewer-controls-answers mt-xs-0 mx-xs-0"><button id="right-answer" class="btn btn-success text-center btn-block" title="Mark this flashcard as CORRECT"><i class="fa fa-check"></i> Correct</button><button id="wrong-answer" class="btn text-center bg-red btn-block" title="Mark this flashcard as INCORRECT"><i class="fa fa-remove"></i> Incorrect</button></div><table class="table stats"><tr><td>Times flipped</td><td id="fc-viewer-tflipped" class="text-right">0</td></tr><tr><td>Marked as <em>correct</em></td><td id="fc-viewer-right" class="text-right">0</td></tr><tr><td>Marked as <em>incorrect</em></td><td id="fc-viewer-wrong" class="text-right">0</td></tr></table><a href="#" class="btn btn-default btn-sm btn-block text-center reset-stats hidden-xs hidden-sm" title="Reset stats for this flashcard" style="margin: 10px 0;"><i class="fa fa-undo"></i> Reset</a> <div class="fc-notes-container hidden-xs hidden-sm"><textarea class="form-control notes fc-back card-notes" rows="4" placeholder="Write your own notes here..." style="resize: none;">
</textarea><a href="#" class="btn btn-default btn-sm btn-block text-center save-notes" title="Save personal notes for this flashcard" style="margin-bottom: 10px;"><i class="fa fa-pencil"></i> Save notes</a> </div><div class="fc-viewer-actions-sm hidden-md hidden-lg"><button type="button" class="btn btn-sm btn-xs-block reset-stats"><i class="fa fa-fw fa-undo"></i>Reset</button> <button type="button" class="btn btn-sm btn-xs-block" data-toggle="modal" data-target="#card-notes-sm-modal"><i class="fa fa-fw fa-pencil"></i>Notes</button><button type="button" class="btn btn-sm btn-xs-block" data-toggle="modal" data-target="#report-problem-sm-modal"><i class="fa fa-fw fa-exclamation-circle"></i>Report error</button></div> </div></div><div class="fc-viewer-controls-bottom hidden-xs hidden-sm"><div class="fc-move"> <button class="btn bg-turquoise text-center disabled" rel="prev" title="Previous flashcard"><i class="fa fa-fw fa-chevron-left"></i>Prev</button><button class="btn bg-turquoise text-center disabled" rel="next" title="Next flashcard">Next<i class="fa fa-fw fa-chevron-right"></i></button></div><div class="fc-actions"><button class="btn btn-default btn-block text-center shuffle"><i class="fa fa-random"></i> Shuffle</button><div class="fc-progress"><div class="progress"><div class="progress-bar"></div></div><div class="text-right"><span class="fc-viewer-results-counter"></span></div></div></div></div><div class="fc-close-sm hidden-md hidden-lg"><button id="fc-xs-close" type="button" class="btn btn-default btn-block text-center" data-dismiss="modal" aria-label="Close">Close</button> <hr class="thin"> <div class="fc-actions" style="width: 100%;"> <button class="btn btn-default btn-block text-center shuffle"> <i class="fa fa-random"></i> Shuffle </button><div class="fc-progress"><div class="progress"><div class="progress-bar"></div></div><div class="text-right"><span class="fc-viewer-results-counter hidden-md hidden-lg"></span></div></div> </div></div></div></div></div><div class="modal-footer"><div id="report-error-container" class="report-problem"><div class="row"><div class="col-md-8"><div class="msg"></div><div class="form-group"><label>Report a problem for flashcard <span class="fc-viewer-id"></span></label><textarea class="form-control issue-description" cols="4"></textarea></div><button type="button" class="btn btn-primary pull-right send-report disabled"><i class="fa fa-paper-plane"></i>Send</button><button id="close-send-report" type="button" class="btn btn-default" style="margin-left: 0;">Close</button></div></div></div></div></div></div></div><div id="card-notes-sm-modal" class="modal fade overlay-modal" tabindex="-1" role="dialog"><div class="modal-dialog modal-sm" role="document"><div class="modal-content"><div class="modal-header p-xs-3"><h4 class="modal-title text-center my-xs-2">Notes</h4></div><div class="modal-body p-xs-3"><textarea class="form-control notes fc-back card-notes p-xs-3" rows="8" style="resize: none;">
</textarea></div><div class="modal-footer p-xs-3"><button type="button" class="btn btn-sm btn-primary btn-xs-block save-notes"><i class="fa fa-fw fa-pencil"></i>Save</button><button type="button" class="btn btn-sm btn-default btn-xs-block mx-xs-0" data-dismiss="modal" aria-label="Close">Close</button></div></div></div></div><div id="report-problem-sm-modal" class="modal fade overlay-modal report-problem" tabindex="-1" role="dialog"><div class="modal-dialog modal-sm" role="document"><div class="modal-content"><div class="modal-header p-xs-3"><h4 class="modal-title text-center my-xs-2">Report a problem for flashcard <span class="fc-viewer-id"></span></h4></div><div class="modal-body p-xs-3"><div class="msg"></div><div class="form-group mb-xs-0"><textarea class="form-control issue-description p-xs-3" rows="8"></textarea></div></div><div class="modal-footer p-xs-3"><button type="button" class="btn btn-sm btn-primary text-center btn-xs-block mb-xs-3 disabled send-report"><i class="fa fa-fw fa-paper-plane"></i>Send</button><button type="button" class="btn btn-sm btn-default text-center btn-xs-block mx-xs-0" data-dismiss="modal" aria-label="Close">Close</button></div></div></div></div> <div id="fcgame-viewer" class="modal fade modal-flashcard" tabindex="-1" role="dialog"> <div class="modal-dialog modal-lg modal-dialog-fcgame" role="document"> <div class="modal-content mc-flashcard modal-content-fcgame"> <div class="modal-header" style="background-color: #fafafa;"> <div class="row text-center" style="width: 100%;"> <div class="col-md-12"> <div style="display: flex; justify-content: space-between; align-items: center;"> <div class="text-left"> Your time: <span class="chronometer c-mobile" id="chronometer">00:00:</span> <span class="chronometer msec c-mobile" id="chronometer-msec">000</span> <br> Your best time: <span class="chronometer c-mobile" id="best-record"></span> </div> <button type="button" class="close" data-dismiss="modal" aria-label="Close"> <span aria-hidden="true">×</span> </button> </div> </div> </div> </div> <div id="fcgame-body" class=" modal-body modal-body-fcgame"> <div class="row-fluid"> <div class="col-lg-12 col-md-12 col-sm-12 fc-content" id="fc-content" style="padding: 15px;"></div> </div> </div> <div id="end-game" style="display: none;"> <div class="col-lg-10 col-lg-offset-1 col-md-10 col-md-offset-1 col-sm-10 col-sm-offset-1 result shadow-bottom"> <div id="end-game-dismiss"></div> <div id="end-game-results"></div> <div id="show-percent" style="margin-bottom: 30px;font-size: 16px;"></div> </div> <div id="end-game-fc" class="col-lg-12"></div> </div> <div id="start-game" class="col-lg-12 col-md-12 col-sm-12 centered"> <div style="width: 200px;"> <button class="btn btn-success btn-xs-block" id="play-game" style="display: block; width: 100%; margin: 10px 0;">Start</button> <button class="btn btn-default btn-xs-block" id="cancel-game" style="display: block; width: 100%; margin: 10px 0;">Cancel</button> </div> </div> <div class="modal-footer"></div> </div> </div></div><div id="fcgame-modal-issue-report" class="modal fade" tabindex="-1" role="dialog"> <div class="modal-dialog" role="document"> <div class="modal-content"> <div class="modal-header"> <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">×</span></button> <h4 class="modal-title">Report error</h4> </div> <div class="modal-body"> <textarea id="issue-description-fcgame" class="form-control"></textarea> </div> <div class="modal-footer"> <button id="send-report-fcgame" type="button" class="btn btn-primary">Send Report</button> </div> </div> </div></div> </article> <hr class="hidden-md hidden-lg"> <div class="hidden-md hidden-lg mt-xs-3"> <button class="btn btn-default btn-block text-xs-center" data-toggle="modal" data-target="#modal-feedback" style="margin-bottom: 10px"><i class="fa fa-send"></i> Feedback</button> </div> </div> <input type="hidden" id="user-id" value="38342"></div><input id="ticket" type="hidden" value="082b9c9c4ae3624d"><input id="tzoffset" type="hidden" value="new"><input id="fp" class="fp" type="hidden" value=""></div><div id="std-footer"> <div class="wmap"> <div class="layout-wrapper"> <p> <a href="https://www.inthinking.net"> © <span id="footer-year"></span> <em>InThinking</em> <script>document.getElementById("footer-year").innerHTML = new Date().getFullYear();</script> </a> | <a target="_self" href="../../../about.html"> About us </a> | <a target="_self" href="../../../terms-and-conditions.html"> Legal </a> | <a target="_self" href="../../../contact.html"> Contact </a> </p> <p> <a class="social" target="_blank" href="https://twitter.com/#!/inthinker"> <img src="../../../img/social/twitter-square.svg"> Twitter </a> <a class="social" target="_blank" href="https://www.facebook.com/inthinking.net"> <img src="../../../img/social/facebook-square.svg"> Facebook </a> <a class="social" target="_blank" href="https://www.linkedin.com/profile/view?id=139741989"> <img src="../../../img/social/linkedin-square.svg"> LinkedIn </a> </p> </div> </div></div><script src="../../../js/jquery-1.11.3.min.js"></script><script src="../../../js/bootstrap.min.js"></script><script src="../../../js/jquery-fancybox/jquery.fancybox.min.js"></script><script>var pageId = 907;</script><script type="text/javascript" src="../../../js/std-galleries.min.js"></script><script type="text/javascript" src="../../../js/jqueryui/jquery-ui-custom.min.js"></script><script type="text/javascript" src="../../../js/jqueryui/jquery.ui.touch-punch.js"></script><script type="text/javascript" src="../../../js/std-quizzes-helpers.min.js?v=20220406"></script><script type="text/javascript" src="../../../js/std-quizzes.min.js?v=2022041300"></script><script type="text/javascript" src="../../../js/jq-boxfit/jquery.boxfit.min.js"></script><script src="../../../ajax/libs/mathjax/2.7.0/MathJax.js?config=TeX-AMS-MML_HTMLorMML"></script><script type="text/javascript" src="../../../js/flashcards/flashcards-utils.min.js?v=202211221200"></script><script type="text/javascript" src="../../../js/flashcards/std-flashcards.min.js?v=202211221000"></script><script type="text/javascript" src="../../../js/hammerjs/hammerjs.min-1.js?v=20220414"></script><script type="text/javascript" src="../../../js/jqueryui/jquery-ui.min.js"></script><script type="text/javascript" src="../../../js/jqueryui/jquery.ui.touch-punch.min.js"></script><script src="../../../js/user/page-my-progress.min.js?v=202211221000"></script><script>var sAJAX='/pages/subjects/activity/user-stats-page.php?t=082b9c9c4ae3624d&p=907&s=7&x=13303';var sData='k4iA6GSB03BgPm1qOd7RPHpsE3KeSVBAEzP5PHpsE39FIxiA6GSB0bfjSYyBPm1FfGyB6bf4W3a1EGLj63cRPYaBWYyDPuBiPFAF7YcHEKvr6GSDPmjoPnyBSnKR74P5GDaSezAFWGcrE0ij6GyDPmjn6GyDEzAF7bKFEYv86GB2Pm1FPFAF7YcrZxP5PBAh63sBWGBDSViq0xvA6GSB0xXqOdS7I3KREGar7nvmZYK8ZGasWxLmEGyR74LjZziv';var loopSecs = 30;var minSecsLog = 60;var lsKey = '7-83606-907';</script><script src="../../../js/subjects/activity/user-stats-page.min.js?v=202205311700"></script><script src="../../../js/subjects/activity/my-favorites.min.js?v=20220610"></script><script src="../../../js/subjects/periodic-table.min.js"></script><script src="../../../js/subjects/feedback.min.js?v=202211221000"></script><script>var sessionUpdateSecs = 300;</script><script type="text/javascript" src="../../../js/session-updater.js"></script><script>(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)})(window,document,'script','https://www.google-analytics.com/analytics.js','ga');ga('create', 'UA-98480796-1', 'auto');ga('send', 'pageview');</script><script src="../../../js/devicefp/devicefp.min.js"></script><script src="../../../js/jq-quickfit/jq-quickfit.min.js?v=20220201"></script><script src="../../../js/frontpage-subjects.min.js?v=202211161300"></script><script type="text/javascript" src="../../../js/studyib-jq.min.js?v=202211241300"></script><script type="text/javascript">$(document).ready(function(){ $('#trigger-modal-video-overview').click(function() { if( $('#modal-video-overview .modal-body iframe').attr('src').length == 0 ) { $('#modal-video-overview .modal-body iframe').attr('src', 'https://www.youtube.com/embed/hxxtdiLdTFk?rel=0'); } }); $('#modal-video-overview').on('hidden.bs.modal', function() { $('#modal-video-overview .modal-body iframe').attr('src', ''); }); });</script></body></html>