File "markSceme-HL-paper1.html"
Path: /IB QUESTIONBANKS/5 Fifth Edition - PAPER/HTML/Chemistry/Topic 8/markSceme-HL-paper1html
File size: 41.13 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-02ef852527079acf252dc4c9b2922c93db8fde2b6bff7c3c7f657634ae024ff1.css">
<link rel="stylesheet" media="print" href="css/print-6da094505524acaa25ea39a4dd5d6130a436fc43336c0bb89199951b860e98e9.css">
<script src="js/application-9717ccaf4d6f9e8b66ebc0e8784b3061d3f70414d8c920e3eeab2c58fdb8b7c9.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>
<!-- - if current_user.is_language_services? && !current_user.is_publishing? -->
<!-- %li= link_to "Language services", tolk_path -->
</ul>
<ul class="nav pull-right">
<li class="dropdown">
<a class="dropdown-toggle" data-toggle="dropdown" href="#">
Help
<b class="caret"></b>
</a>
<ul class="dropdown-menu">
<li><a href="https://questionbank.ibo.org/video_tour?locale=en">Video tour</a></li>
<li><a href="https://questionbank.ibo.org/instructions?locale=en">Detailed instructions</a></li>
<li><a target="_blank" href="https://ibanswers.ibo.org/">IB Answers</a></li>
</ul>
</li>
<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 class="pull-right screen_only"><a class="btn btn-small btn-info" href="https://questionbank.ibo.org/updates?locale=en">Updates to Questionbank</a></div>
<p class="muted language_chooser">
User interface language:
<a href="https://questionbank.ibo.org/en/users/set_user_locale?new_locale=en">English</a>
|
<a href="https://questionbank.ibo.org/en/users/set_user_locale?new_locale=es">Español</a>
</p>
</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="https://mirror.ibdocs.top/qb.png" alt="Ib qb 46 logo">
</div>
</div>
</div>
<h2>HL Paper 1</h2><div class="question">
<p>What is correct for pure hot water?<br><br></p>
<p><img src="data:image/png;base64,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"></p>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question">
<p>B</p>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question">
[N/A]
</div>
<br><hr><br><div class="question">
<p>What is the pH of 1.0 × 10<sup>−3</sup> mol dm<sup>−3</sup> sodium hydroxide, NaOH(aq)?</p>
<p><em>K</em><sub>w</sub> = 1.0 × 10<sup>−14</sup></p>
<p>A. 3</p>
<p>B. 4</p>
<p>C. 10</p>
<p>D. 11</p>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question">
<p>D</p>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question">
[N/A]
</div>
<br><hr><br><div class="question">
<p><span style="background-color: #ffffff;">Which solution is basic at 25 °C?</span></p>
<p style="text-align: center;"><span style="background-color: #ffffff;">K<sub>w</sub> = 1.0 × 10<sup>−14</sup></span></p>
<p><span style="background-color: #ffffff;">A. [H<sup>+</sup>] = 1.0 × 10<sup>−3</sup> mol dm<sup>−3</sup></span></p>
<p><span style="background-color: #ffffff;">B. [OH<sup>−</sup>] = 1.0 × 10<sup>−13</sup> mol dm<sup>−3</sup></span></p>
<p><span style="background-color: #ffffff;">C. solution of pH = 4.00</span></p>
<p><span style="background-color: #ffffff;">D. [H<sub>3</sub>O<sup>+</sup>] = 1.0 × 10<sup>−13</sup> mol dm<sup>−3</sup></span></p>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question">
<p>D</p>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question">
<p>This had the highest discriminatory index on the exam. Most of the incorrect answers indicated that a basic solution would have <strong>[OH<sup>-</sup> ] = 1.0 x 10<sup>-13</sup> mol dm<sup>-3</sup> rather than [H<sub>3</sub>O<sup>+</sup> ] = 1.0 x 10<sup>-13</sup> mol dm<sup>-3</sup></strong> .</p>
</div>
<br><hr><br><div class="question">
<p><span style="background-color: #ffffff;">What is the major reason why the pH of unpolluted rain is less than 7?</span></p>
<p><span style="background-color: #ffffff;">A. methane</span></p>
<p><span style="background-color: #ffffff;">B. carbon dioxide</span></p>
<p><span style="background-color: #ffffff;">C. nitrogen oxides</span></p>
<p><span style="background-color: #ffffff;">D. sulfur dioxide</span></p>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question">
<p>B</p>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question">
<p>69 % of the candidates identified CO2 as the gas responsible for the acidity of unpolluted rain. The majority of the candidates that answered incorrectly chose nitrogen oxides (C) or sulfur dioxide (D).</p>
</div>
<br><hr><br><div class="question">
<p><span class="fontstyle0">Which of these oxides contribute to acid deposition?</span></p>
<p style="padding-left:30px;"><span class="fontstyle0">I. </span><math xmlns="http://www.w3.org/1998/Math/MathML" class="wrs_chemistry"><msub><mi>SO</mi><mn>2</mn></msub></math><span class="fontstyle0"><br></span><span class="fontstyle0">II. </span><math xmlns="http://www.w3.org/1998/Math/MathML" class="wrs_chemistry"><msub><mi>NO</mi><mn>2</mn></msub></math><span class="fontstyle0"><br></span><span class="fontstyle0">III. </span><math xmlns="http://www.w3.org/1998/Math/MathML" class="wrs_chemistry"><msub><mi>CO</mi><mn>2</mn></msub></math></p>
<p><span class="fontstyle0">A. I and II only<br></span></p>
<p><span class="fontstyle0">B. I and III only<br></span></p>
<p><span class="fontstyle0">C. II and III only<br></span></p>
<p><span class="fontstyle0">D. I, II and III</span></p>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question">
<p>A</p>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question">
<p>Not well answered. Less than half knew which oxides contribute to acid deposition, with the majority including CO<sub>2</sub> in the list. This misconception was held by higher and lower scoring candidates equally.</p>
</div>
<br><hr><br><div class="question">
<p><span class="fontstyle0">Which species is a Lewis acid but </span><span class="fontstyle2"><strong>not</strong> </span><span class="fontstyle0">a Brønsted–Lowry acid?</span></p>
<p><span class="fontstyle0">A. <math xmlns="http://www.w3.org/1998/Math/MathML" class="wrs_chemistry"><msup><mi>Cu</mi><mrow><mn>2</mn><mo>+</mo></mrow></msup></math></span><span class="fontstyle3"><br></span></p>
<p><span class="fontstyle0">B. <math xmlns="http://www.w3.org/1998/Math/MathML" class="wrs_chemistry"><msup><msub><mi>NH</mi><mn>4</mn></msub><mo>+</mo></msup></math></span><span class="fontstyle3"><br></span></p>
<p><span class="fontstyle0">C. <math xmlns="http://www.w3.org/1998/Math/MathML" class="wrs_chemistry"><mi>Cu</mi></math><br></span></p>
<p><span class="fontstyle0">D. <math xmlns="http://www.w3.org/1998/Math/MathML" class="wrs_chemistry"><msub><mi>CH</mi><mn>3</mn></msub><mi>COOH</mi></math></span></p>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question">
<p>A</p>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question">
<p>Vast majority of candidates understood the difference between Lewis and Brønsted Lowry acids.</p>
</div>
<br><hr><br><div class="question">
<p>Which species produced by the successive dissociations of phosphoric acid, H<sub>3</sub>PO<sub>4</sub>, are amphiprotic?</p>
<p>A. HPO<sub>4</sub><sup>2−</sup> and PO<sub>4</sub><sup>3−</sup></p>
<p>B. H<sub>2</sub>PO<sub>4</sub><sup>−</sup> and HPO<sub>4</sub><sup>2−</sup></p>
<p>C. H<sub>2</sub>PO<sub>4</sub><sup>−</sup> and PO<sub>4</sub><sup>3−</sup></p>
<p>D. HPO<sub>4</sub><sup>2−</sup> only</p>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question">
<p>B</p>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question">
[N/A]
</div>
<br><hr><br><div class="question">
<p>What is the pH of 0.01 mol dm<sup>−3</sup> KOH (aq)?</p>
<p><br>A. 1.0</p>
<p>B. 2.0</p>
<p>C. 12.0</p>
<p>D. 13.0</p>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question">
<p>C</p>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question">
[N/A]
</div>
<br><hr><br><div class="question">
<p>What describes HPO<sub>4</sub><sup>2−</sup>?</p>
<p>A. Amphiprotic but not amphoteric</p>
<p>B. Amphoteric but not amphiprotic</p>
<p>C. Amphiprotic and amphoteric</p>
<p>D. Neither amphiprotic nor amphoteric</p>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question">
<p>C</p>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question">
[N/A]
</div>
<br><hr><br><div class="question">
<p><span class="fontstyle0">What is the pH of an ammonia solution that has </span><math xmlns="http://www.w3.org/1998/Math/MathML" class="wrs_chemistry"><mo>[</mo><msup><mi>OH</mi><mo>-</mo></msup><mo>]</mo><mo>=</mo><mn>1</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>-</mo><mn>4</mn></mrow></msup><mo> </mo><mi>mol</mi><mo> </mo><msup><mi>dm</mi><mrow><mo>-</mo><mn>3</mn></mrow></msup></math><span class="fontstyle0">?</span></p>
<p><span class="fontstyle0">A. <math xmlns="http://www.w3.org/1998/Math/MathML"><mn>4</mn><mo>.</mo><mn>0</mn></math><br></span></p>
<p><span class="fontstyle0">B. <math xmlns="http://www.w3.org/1998/Math/MathML"><mn>8</mn><mo>.</mo><mn>0</mn></math><br></span></p>
<p><span class="fontstyle0">C. <math xmlns="http://www.w3.org/1998/Math/MathML"><mn>10</mn><mo>.</mo><mn>0</mn></math><br></span></p>
<p><span class="fontstyle0">D. </span><math xmlns="http://www.w3.org/1998/Math/MathML"><mn>12</mn><mo>.</mo><mn>0</mn></math></p>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question">
<p>C</p>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question">
<p>More than 86% of candidates could find a pH from a given hydroxide concentration.</p>
</div>
<br><hr><br><div class="question">
<p>What happens to the amount of hydroxide ions and hydroxide ion concentration when water is added to a solution of NH<sub>3 </sub>(aq)?</p>
<p><img src="data:image/png;base64,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"></p>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question">
<p>C</p>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question">
<p>35% of the candidates deduced the change in amount of OH<sup>-</sup> and [OH<sup>-</sup>] when water is added to NH<sub>3</sub>(aq). The majority of candidates recognized the increase in the amount of OH<sup>-</sup> due to the shift in the equilibrium position but assumed that the concentration of OH<sup>-</sup> increased as well ignoring the effect of the dilution. Some teachers commented that this question was too complicated.</p>
</div>
<br><hr><br><div class="question">
<p>Which species acts as a Lewis and Brønsted–Lowry base?</p>
<p>A. [Al(H<sub>2</sub>O)<sub>6</sub>]<sup>3+</sup></p>
<p>B. BF<sub>3</sub></p>
<p>C. NH<sub>4</sub><sup>+</sup></p>
<p>D. OH<sup>−</sup></p>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question">
<p>D</p>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question">
[N/A]
</div>
<br><hr><br><div class="question">
<p>Which is a Lewis acid, but not a Brønsted-Lowry acid?</p>
<p>A. <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mtext>BF</mtext><mn>3</mn></msub></math></p>
<p>B. <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mtext>H</mtext><mtext>3</mtext></msub><msup><mtext>O</mtext><mtext>+</mtext></msup></math></p>
<p>C. <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mtext>NH</mtext><mn>3</mn></msub></math></p>
<p>D. <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mtext>Cl</mtext><mo>-</mo></msup></math></p>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question">
<p>A</p>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question">
[N/A]
</div>
<br><hr><br><div class="question">
<p>What is a possible value of pH at the equivalence point in the titration of a strong acid with a weak base?</p>
<p><br>A. 5</p>
<p>B. 7</p>
<p>C. 9</p>
<p>D. 11</p>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question">
<p>A</p>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question">
[N/A]
</div>
<br><hr><br><div class="question">
<p><span style="background-color: #ffffff;">What is the pH of 0.001 mol dm<sup>−3</sup> NaOH (aq)?</span></p>
<p><span style="background-color: #ffffff;">A. 1</span></p>
<p><span style="background-color: #ffffff;">B. 3</span></p>
<p><span style="background-color: #ffffff;">C. 11</span></p>
<p><span style="background-color: #ffffff;">D. 13</span></p>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question">
<p>C</p>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question">
<p>77 % of the candidates were able to calculate the pH of the aqueous solution of NaOH. The most commonly chosen distractor was D (pH = 13) which was probably selected because NaOH is a strong base.</p>
</div>
<br><hr><br><div class="question">
<p>What is the pH of a solution in which the hydroxide ion concentration is 1 × 10<sup>−11</sup> mol dm<sup>−3</sup> at 298 K?</p>
<p style="text-align: center;"><em>K</em><sub>w</sub> = 1 × 10<sup>−14</sup> at 298 K</p>
<p>A. 3</p>
<p>B. 7</p>
<p>C. 11</p>
<p>D. 14</p>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question">
<p>A</p>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question">
[N/A]
</div>
<br><hr><br><div class="question">
<p><span style="background-color: #ffffff;">With which do most acids react?</span></p>
<p><span style="background-color: #ffffff;"> I. sodium hydrogen carbonate<br> II. magnesium<br> III. calcium sulfate<br></span></p>
<p><span style="background-color: #ffffff;">A. I and II only</span></p>
<p><span style="background-color: #ffffff;">B. I and III only</span></p>
<p><span style="background-color: #ffffff;">C. II and III only</span></p>
<p><span style="background-color: #ffffff;">D. I, II and III</span></p>
</div>
<h2 style="margin-top: 1em">Markscheme</h2>
<div class="question">
<p>A</p>
</div>
<h2 style="margin-top: 1em">Examiners report</h2>
<div class="question">
<p>This question on reactivity of acids with carbonates and metals (first bullet point in Topic 8.2) confused higher and lower scoring candidates alike and was the worst answered question in paper 1. One teacher commented “The question does not seem clear. They would all react with acids, but what does “most acids” mean?”.</p>
</div>
<br><hr><br>