File "markSceme-SL-paper3.html"
Path: /IB QUESTIONBANKS/4 Fourth Edition - PAPER/HTML/Chemistry/Topic 2/markSceme-SL-paper3html
File size: 16.33 KB
MIME-type: text/html
Charset: utf-8
<!DOCTYPE html>
<html>
<meta http-equiv="content-type" content="text/html;charset=utf-8">
<head>
<meta charset="utf-8">
<title>IB Questionbank</title>
<link rel="stylesheet" media="all" href="css/application-746ec5d03ead8d9e8b3bb7d32173f2b4e2e22a05f0c5278e086ab55b3c9c238e.css">
<link rel="stylesheet" media="print" href="css/print-6da094505524acaa25ea39a4dd5d6130a436fc43336c0bb89199951b860e98e9.css">
<script src="js/application-3c91afd8a2942c18d21ed2700e1bdec14ada97f1d3788ae229315e1276d81453.js"></script>
<script type="text/javascript" async src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.5/MathJax.js?config=TeX-MML-AM_CHTML-full"></script>
<!--[if lt IE 9]>
<script src='https://cdnjs.cloudflare.com/ajax/libs/html5shiv/3.7.3/html5shiv.min.js'></script>
<![endif]-->
<meta name="csrf-param" content="authenticity_token">
<meta name="csrf-token" content="iHF+M3VlRFlNEehLVICYgYgqiF8jIFlzjGNjIwqOK9cFH3ZNdavBJrv/YQpz8vcspoICfQcFHW8kSsHnJsBwfg==">
<link href="favicon.ico" rel="shortcut icon">
</head>
<body class="teacher questions-show">
<div class="navbar navbar-fixed-top">
<div class="navbar-inner">
<div class="container">
<div class="brand">
<div class="inner"><a href="http://ibo.org/">ibo.org</a></div>
</div>
<ul class="nav">
<li>
<a href="../../index.html">Home</a>
</li>
<li class="active dropdown">
<a class="dropdown-toggle" data-toggle="dropdown" href="#">
Questionbanks
<b class="caret"></b>
</a><ul class="dropdown-menu">
<li>
<a href="../../geography.html" target="_blank">DP Geography</a>
</li>
<li>
<a href="../../physics.html" target="_blank">DP Physics</a>
</li>
<li>
<a href="../../chemistry.html" target="_blank">DP Chemistry</a>
</li>
<li>
<a href="../../biology.html" target="_blank">DP Biology</a>
</li>
<li>
<a href="../../furtherMath.html" target="_blank">DP Further Mathematics HL</a>
</li>
<li>
<a href="../../mathHL.html" target="_blank">DP Mathematics HL</a>
</li>
<li>
<a href="../../mathSL.html" target="_blank">DP Mathematics SL</a>
</li>
<li>
<a href="../../mathStudies.html" target="_blank">DP Mathematical Studies</a>
</li>
</ul></li>
<!-- - if current_user.is_language_services? && !current_user.is_publishing? -->
<!-- %li= link_to "Language services", tolk_path -->
</ul>
<ul class="nav pull-right">
<li>
<a href="https://06082010.xyz">IB Documents (2) Team</a>
</li></ul>
</div>
</div>
</div>
<div class="page-content container">
<div class="row">
<div class="span24">
</div>
</div>
<div class="page-header">
<div class="row">
<div class="span16">
<p class="back-to-list">
</p>
</div>
<div class="span8" style="margin: 0 0 -19px 0;">
<img style="width: 100%;" class="qb_logo" src="images/logo.jpg" alt="Ib qb 46 logo">
</div>
</div>
</div><h2>SL Paper 3</h2><div class="specification">
<p class="p1">Selected regions of the electromagnetic spectrum are represented in order of increasing frequency below.</p>
<p class="p1" style="text-align: center;"><img src="images/Schermafbeelding_2016-10-30_om_11.22.37.png" alt="M11/4/CHEMI/SP3/ENG/TZ2/A1"></p>
</div>
<div class="question" style="padding-left: 20px; padding-right: 20px;">
<p class="p1">Identify region <strong>A</strong>.</p>
<div class="marks">[1]</div>
<div class="question_part_label">a.</div>
</div>
<div class="question" style="padding-left: 20px; padding-right: 20px;">
<p class="p1">State which region of the electromagnetic spectrum can be used to identify the functional groups present in a molecule.</p>
<div class="marks">[1]</div>
<div class="question_part_label">c.</div>
</div>
<div class="question" style="padding-left: 20px; padding-right: 20px;">
<p class="p1">Explain why the absorptions in infrared (IR) spectroscopy occur at much higher frequency than those in \(^{\text{1}}{\text{H}}\,{\text{NMR}}\) spectroscopy.</p>
<div class="marks">[2]</div>
<div class="question_part_label">d.</div>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question" style="padding-left: 20px;">
<p class="p1">radio(wave);</p>
<div class="question_part_label">a.</div>
</div>
<div class="question" style="padding-left: 20px;">
<p class="p1">infrared/IR;</p>
<div class="question_part_label">c.</div>
</div>
<div class="question" style="padding-left: 20px;">
<p class="p1">IR involves vibrations of bonds / IR involves shorter wavelength/more energy than \(^{\text{1}}{\text{H}}\,{\text{NMR}}\);</p>
<p class="p1">whereas \(^{\text{1}}{\text{H}}\,{\text{NMR}}\) involves transitions between different energy states in the nucleus which are lower in energy / \(^{\text{1}}{\text{H}}\,{\text{NMR}}\) occurs in the radio region therefore energy is lower;</p>
<div class="question_part_label">d.</div>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question" style="padding-left: 20px;">
<p class="p1">Most candidates were familiar with regions of the electromagnetic spectrum and their uses, but had difficulty describing the relationship between energy and frequency or wavelength.</p>
<div class="question_part_label">a.</div>
</div>
<div class="question" style="padding-left: 20px;">
<p class="p1">Most candidates were familiar with regions of the electromagnetic spectrum and their uses, but had difficulty describing the relationship between energy and frequency or wavelength.</p>
<div class="question_part_label">c.</div>
</div>
<div class="question" style="padding-left: 20px;">
<p class="p1">Most candidates were familiar with regions of the electromagnetic spectrum and their uses, but had difficulty describing the relationship between energy and frequency or wavelength.</p>
<div class="question_part_label">d.</div>
</div>
<br><hr><br><div class="specification">
<p>Modern analytical techniques are used widely for different purposes in everyday life.</p>
</div>
<div class="question">
<p>Two types of spectroscopy are absorption and emission. Distinguish between each type of spectra, including how each is produced.</p>
<p> </p>
<p>Absorption spectra:</p>
<p> </p>
<p> </p>
<p> </p>
<p> </p>
<p> </p>
<p> </p>
<p>Emission spectra:</p>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question">
<p><em>Absorption spectra</em>:</p>
<p>(when radiation is passed through sample) atom/ion/molecule becomes excited <em>/ </em>electrons raised to higher energy level/state / <em>OWTTE</em>;</p>
<p>only specific frequencies/wavelengths absorbed / black lines on a coloured background / spectrum shows where absorption happens, such as dips (in the IR spectrum) / <em>OWTTE</em>;</p>
<p><em>Emission spectra</em>:</p>
<p>(energy given out by) excited atom/ion/molecule moves to lower energy state / excited electrons move to lower energy level/ground state / <em>OWTTE</em>;</p>
<p>colours same as those missing from absorption spectra / coloured lines on black background / only specific frequencies/wavelengths emitted / <em>OWTTE</em>;</p>
<p><em>Difference may also be shown by two different representations of spectra.</em></p>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question">
<p>Answers generally showed understanding of the relationship between the spectra and electronic transitions. Some candidates failed to highlight that emission spectra are obtained from an excited sample.</p>
</div>
<br><hr><br><div class="specification">
<p>Electromagnetic waves can transfer energy and carry information.</p>
</div>
<div class="question">
<p>State the relationship between the energy of a wave and its wavelength.</p>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question">
<p>\(E = \frac{{hc}}{\lambda }/E = \alpha \frac{1}{\lambda }\) / energy inversely proportional to wavelength / the higher the energy the shorter the wavelength / <em>OWTTE</em>;</p>
<p><em>Do not accept </em>\(E = h\upsilon /hf\).</p>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question">
<p>Most students scored the mark but only a few of them stated the quantitative relationship (inverse proportionality).</p>
</div>
<br><hr><br><div class="question" style="padding-left: 20px; padding-right: 20px;">
<p>Describe the essential difference between the <strong>emission</strong> spectrum of sodium and the <strong>absorption</strong> spectrum of sodium.</p>
<div class="marks">[1]</div>
<div class="question_part_label">a.</div>
</div>
<div class="question" style="padding-left: 20px; padding-right: 20px;">
<p>Identify the five missing components in the following table.</p>
<p style="text-align: center;"><img src="images/Schermafbeelding_2016-08-18_om_09.21.27.png" alt="M14/4/CHEMI/SP3/ENG/TZ1/01.b"></p>
<div class="marks">[4]</div>
<div class="question_part_label">b.</div>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question" style="padding-left: 20px;">
<p><em>Emission spectrum</em>: coloured lines <strong>and </strong><em>Absorption spectrum</em>: black/dark lines;</p>
<p><strong>OR</strong></p>
<p><em>Emission spectrum</em>: lines <strong>and </strong><em>Absorption spectrum</em>: continuous;</p>
<p><em>Allow “Emission spectrum: electrons emit energy as they drop to lower energy </em><em>levels </em><strong><em>and </em></strong><em>Absorption spectrum: electrons absorb energy as they are promoted to </em><em>higher energy levels” / OWTTE.</em></p>
<div class="question_part_label">a.</div>
</div>
<div class="question" style="padding-left: 20px;">
<p><img src="images/Schermafbeelding_2016-08-18_om_09.23.12.png" alt="M14/4/CHEMI/SP3/ENG/TZ1/01.b/M"> ;</p>
<p><em>For M4 both visible/UV/atomic absorption/AA for type of spectroscopy </em><strong><em>and</em></strong><em> region of EMS required.</em></p>
<div class="question_part_label">b.</div>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question" style="padding-left: 20px;">
<p>Students found it difficult to explain clearly the difference between emission and absorption spectra for part (a). Most candidates successful in gaining the mark, described the difference in terms of energy released or absorbed by the electrons. There was lack of understanding however for the difference in the coloured and the dark lines produced by the two spectra. Candidates who described the difference in terms of coloured lines or continuous spectrum had difficulty attaining the mark. Very few students achieved all 4 points for part (b). Most had difficulty completing the information for \(^{\text{1}}{\text{H}}\,{\text{NMR}}\). Many stated a number for what was measured instead of the atomic/molecular process e.g. chemical shift as opposed to nuclear spin. Candidates were well prepared for answering part (c) often, stating concentration of the element as the answer.</p>
<div class="question_part_label">a.</div>
</div>
<div class="question" style="padding-left: 20px;">
<p>Students found it difficult to explain clearly the difference between emission and absorption spectra for part (a). Most candidates successful in gaining the mark, described the difference in terms of energy released or absorbed by the electrons. There was lack of understanding however for the difference in the coloured and the dark lines produced by the two spectra. Candidates who described the difference in terms of coloured lines or continuous spectrum had difficulty attaining the mark. Very few students achieved all 4 points for part (b). Most had difficulty completing the information for \(^{\text{1}}{\text{H}}\,{\text{NMR}}\). Many stated a number for what was measured instead of the atomic/molecular process e.g. chemical shift as opposed to nuclear spin. Candidates were well prepared for answering part (c) often, stating concentration of the element as the answer.</p>
<div class="question_part_label">b.</div>
</div>
<br><hr><br><div class="specification">
<p class="p1">Paper chromatography is a simple method used to separate and identify the components in a mixture. To aid identification, the retention factor, \({R_{\text{f}}}\), of an unknown component can be compared with the \({R_{\text{f}}}\) values of pure samples of the possible components.</p>
</div>
<div class="question">
<p class="p1">Describe how the wavelength, the frequency, and the energy, change in moving from the infrared region of the electromagnetic spectrum to the radio region of the electromagnetic spectrum.</p>
<p class="p2"> </p>
<p class="p1">Wavelength:</p>
<p class="p2"> </p>
<p class="p1">Frequency:</p>
<p class="p2"> </p>
<p class="p1">Energy:</p>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question">
<p class="p1"><em>Wavelength</em>: increases/longer;</p>
<p class="p1"><em>Frequency</em>: decreases/lower;</p>
<p class="p1"><em>Energy</em>: decreases/lower;</p>
<p class="p1"><em>Accept “weaker”.</em></p>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question">
<p class="p1">The components of the double beam spectrometer seemed to be well known, though in the first part many said a monochromator “emitted” light of a single wavelength, incorrectly implying it was the light source. Many candidates knew that IR absorption depended on vibrations and polarity, though only a few gained the second mark by specifying a change in polarity. The final section appeared to well understood by candidates, with even the weakest students usually scoring full marks.</p>
</div>
<br><hr><br><div class="specification">
<p>Nuclear fission of <sup>235</sup>U is one source of electrical energy that has a minimal carbon footprint.</p>
</div>
<div class="question" style="padding-left: 20px; padding-right: 20px;">
<p>Natural uranium needs to be enriched to increase the proportion of <sup>235</sup>U. Suggest a technique that would determine the relative abundances of <sup>235</sup>U and <sup>238</sup>U.</p>
<div class="marks">[1]</div>
<div class="question_part_label">a.i.</div>
</div>
<div class="question" style="padding-left: 20px; padding-right: 20px;">
<p>Explain how <sup>235</sup>U fission results in a chain reaction, including the concept of critical mass.</p>
<div class="marks">[3]</div>
<div class="question_part_label">a.ii.</div>
</div>
<div class="question" style="padding-left: 20px; padding-right: 20px;">
<p>Suggest one reason why there is opposition to the increased use of nuclear fission reactors.</p>
<div class="marks">[1]</div>
<div class="question_part_label">b.</div>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question" style="padding-left: 20px;">
<p>mass spectrometry/mass spectroscopy/MS</p>
<p> </p>
<p><em>Accept “analysis of radiation emitted”.</em></p>
<p><strong><em>[1 mark]</em></strong></p>
<div class="question_part_label">a.i.</div>
</div>
<div class="question" style="padding-left: 20px;">
<p><em>critical mass: </em>mass required so that <strong>«</strong>on average<strong>» </strong>each fission/reaction results in a further fission/reaction</p>
<p><em>Any two for </em><strong><em>[2 max]</em></strong><em>:</em></p>
<p>neutron captured by <strong>«</strong><sup>235</sup>U<strong>» </strong>nucleus</p>
<p>fission/reaction produces many neutrons/more than one neutron</p>
<p>if these cause further fission/reaction a chain reaction occurs</p>
<p> </p>
<p><em>Accept “minimum mass of fuel needed </em><em>for the reaction to be self-sustaining”.</em></p>
<p><em>Accept answers in the form of suitable </em><em>diagrams/equations.</em></p>
<p><strong><em>[3 marks]</em></strong></p>
<div class="question_part_label">a.ii.</div>
</div>
<div class="question" style="padding-left: 20px;">
<p>produce long lived/long half-life radioisotopes/radioactivity</p>
<p><strong><em>OR</em></strong></p>
<p>could be used to produce nuclear weapons</p>
<p><strong><em>OR</em></strong></p>
<p><strong>«</strong>nuclear<strong>» </strong>accidents/meltdowns can occur</p>
<p> </p>
<p><em>Accept “long lived/long half-life </em><em>radioactive waste”.</em></p>
<p><strong><em>[1 mark]</em></strong></p>
<div class="question_part_label">b.</div>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question" style="padding-left: 20px;">
[N/A]
<div class="question_part_label">a.i.</div>
</div>
<div class="question" style="padding-left: 20px;">
[N/A]
<div class="question_part_label">a.ii.</div>
</div>
<div class="question" style="padding-left: 20px;">
[N/A]
<div class="question_part_label">b.</div>
</div>
<br><hr><br>