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	<title>DP Chemistry: Entropy & spontaneity  </title>
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  <meta name="description" content="Entropy is paradoxically probably one of the hardest and one of the easiest topics to teach! Hardest because a full understanding of entropy really requires knowledge of statistical thermodynamics; easiest because at this level it can be related simply to the idea of disorder and the questions asked in the examination are usually very straightforward.If you tell your students that &quot;nature tends to disorder&quot; which is...">
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href="../19290/introduction-to-biochemistry--1.html">Introduction to biochemistry  </a></li><li><a href="../19287/proteins-enzymes--1.html">Proteins & enzymes </a></li><li><a href="../19291/lipids-1.html">Lipids</a></li><li><a href="../19299/carbohydrates--1.html">Carbohydrates </a></li><li><a href="../19305/vitamins--1.html">Vitamins   </a></li><li><a href="../19313/biochemistry-the-environment--1.html">Biochemistry & the environment </a></li><li><a href="../19336/proteins-enzymes-ahl--1.html">Proteins & enzymes (AHL)   </a></li><li><a href="../19347/nucleic-acids--1.html">Nucleic acids   </a></li><li><a href="../19361/biological-pigments--1.html">Biological pigments   </a></li><li><a href="../19366/stereochemistry-in-biomolecules-1.html">Stereochemistry in biomolecules</a></li></ul></li><li><a href="../19390/option-c--1.html" class="father">Option C </a><ul class="level-2"><li><a href="../19391/energy-sources-1.html">Energy sources</a></li><li><a href="../19407/fossil-fuels-1.html">Fossil fuels</a></li><li><a href="../19411/nuclear-fusion-nuclear-fission-reactions-1.html">Nuclear fusion & nuclear fission reactions</a></li><li><a href="../19429/solar-energy-1.html">Solar energy</a></li><li><a href="../19437/environmental-impact-global-warming-1.html">Environmental impact - global warming</a></li><li><a href="../19453/electrochemistry-rechargeable-batteries-fuel-cells-1.html">Electrochemistry, rechargeable batteries & fuel cells</a></li><li><a href="../19458/nuclear-fusion-fission-hl--1.html">Nuclear fusion & fission (HL)    </a></li><li><a href="../19470/photovoltaic-cells-and-dsscs-1.html">Photovoltaic cells and DSSCs</a></li></ul></li><li><a href="../19078/option-d-1.html" class="father">Option D</a><ul class="level-2"><li><a href="../19079/pharmaceutical-products-drug-action--1.html">Pharmaceutical products & drug action </a></li><li><a href="../19158/aspirin-penicillin--1.html">Aspirin & penicillin  </a></li><li><a href="../19174/opiates-1.html">Opiates</a></li><li><a href="../19184/ph-regulation-of-the-stomach-1.html">pH regulation of the stomach</a></li><li><a href="../19194/antiviral-medications--1.html">Antiviral medications </a></li><li><a href="../19211/environmental-impact-of-some-medications-1.html">Environmental impact of some medications</a></li><li><a href="../19254/taxol-a-chiral-auxiliary-case-study-1.html">Taxol - a chiral auxiliary case study</a></li><li><a href="../19258/nuclear-medicine--1.html">Nuclear medicine  </a></li><li><a href="../19273/drug-detection-analysis--1.html">Drug detection & analysis </a></li></ul></li></ul></li><li><a href="../16592/practical-scheme-of-work-ia--1.html">Practical scheme of work & IA </a><ul class="level-1"><li><a href="../16682/internal-assessment-1.html" class="father">Internal Assessment</a><ul class="level-2"><li><a href="../18892/scaffolding-the-investigation-1.html">&#039;Scaffolding&#039; the investigation</a></li><li><a href="../18896/timing-organisation--1.html">Timing & organisation </a></li><li><a href="../18905/choosing-the-research-question-1.html">Choosing the research question</a></li><li><a href="../18946/personal-engagement-1.html">Personal engagement</a></li><li><a href="../18950/exploration-1.html">Exploration</a></li><li><a href="../18957/analysis-1.html">Analysis</a></li><li><a href="../18965/evaluation-1.html">Evaluation</a></li><li><a href="../18966/communication-1.html">Communication</a></li><li><a href="../19882/internal-standardization-of-the-ia-1.html">Internal standardization of the IA</a></li><li><a href="../19901/submitting-the-samples-for-moderation-2.html">Submitting the samples for moderation</a></li><li><a href="../33754/ten-suggestions-for-ias-using-secondary-data-1.html">Ten suggestions for IAs using secondary data</a></li><li><a href="../37544/gaining-full-marks-for-a-databased-ia--1.html">Gaining full marks for a databased IA </a></li><li><a href="../19506/ia-example-marking-exercise--1.html">IA example & marking exercise </a></li><li><a href="../23929/genuine-examples-of-moderated-ia-reports-1.html">Genuine examples of moderated IA reports</a></li><li><a href="../25234/examples-of-teacher-marked-ia-reports--1.html">Examples of teacher-marked IA reports </a></li><li><a href="../37542/history-of-internal-assessment-1.html">History of Internal Assessment</a></li></ul></li><li><a href="../16598/mandatory-laboratory-components-1.html" class="father">Mandatory laboratory components</a><ul class="level-2"><li><a href="../16613/formula-of-magnesium-oxide--1.html">Formula of magnesium oxide </a></li><li><a href="../16612/determining-the-mr-of-an-unknown-gas-1.html">Determining the <i>M</i><sub>r</sub> of an unknown gas</a></li><li><a href="../16615/acid-base-titrations--1.html">Acid-base titrations </a></li><li><a href="../16616/a-green-acid-base-practical-1.html">A green acid-base practical</a></li><li><a href="../16617/analysis-of-aspirin-tablets-1.html">Analysis of aspirin tablets</a></li><li><a href="../16618/caco3-in-egg-shells-1.html">CaCO<sub>3</sub> in egg shells</a></li><li><a href="../16644/enthalpy-changes-1.html">Enthalpy changes</a></li><li><a href="../16631/reaction-rates-1.html">Reaction rates</a></li><li><a href="../16635/rate-dependent-factors-1.html">Rate-dependent factors</a></li><li><a href="../16636/determining-ea-for-a-reaction-1.html">Determining <i>E</i><sub>a</sub> for a reaction</a></li><li><a href="../16637/iodination-of-propanone-1.html">Iodination of propanone</a></li><li><a href="../18144/titrations-with-a-ph-meter-1.html">Titrations with a pH meter</a></li><li><a href="../18355/redox-titration-with-kmno4--1.html">Redox titration with KMnO<sub>4</sub> </a></li><li><a href="../16640/voltaic-cells-1.html">Voltaic cells</a></li><li><a href="../16659/3-d-molecular-modelling--1.html">3-D molecular modelling </a></li></ul></li><li><a href="../17168/other-good-practicals-1.html" class="father">Other good practicals</a><ul class="level-2"><li><a href="../17196/common-chemical-reactions-1.html">Common chemical reactions</a></li><li><a href="../227/elements-oxides-of-the-third-period--1.html">Elements & oxides of the third period </a></li><li><a href="../17239/the-halogens-1.html">The halogens</a></li><li><a href="../17162/boiling-points-of-mixtures-1.html">Boiling points of mixtures</a></li><li><a href="../17170/polarity-of-molecules-1.html">Polarity of molecules</a></li><li><a href="../18083/le-chateliers-principle--1.html">Le Chatelier&#039;s principle </a></li><li><a href="../19582/determining-kc-for-an-esterification-reaction-1.html">Determining <i>K</i><sub>c</sub> for an esterification reaction</a></li><li><a href="../18164/redox-reactions-of-vanadium--1.html">Redox reactions of vanadium </a></li><li><a href="../18351/chlorine-in-swimming-pools--1.html">Chlorine in swimming pools </a></li><li><a href="../18178/analysis-of-cuii-ions-in-solution--1.html">Analysis of Cu(II) ions in solution </a></li><li><a href="../18179/percentage-of-copper-in-brass-1.html">Percentage of copper in brass</a></li><li><a href="../18356/electrolytic-cells--1.html">Electrolytic cells </a></li><li><a href="../18598/reactions-of-organic-compounds-1.html">Reactions of organic compounds</a></li><li><a href="../18752/hydrolysis-of-halogenoalkanes-1.html">Hydrolysis of halogenoalkanes</a></li><li><a href="../18784/preparation-of-13-dinitrobenzene--1.html">Preparation of 1,3-dinitrobenzene </a></li><li><a href="../19022/determination-of-an-organic-structure-1.html">Determination of an organic structure</a></li><li><a href="../19887/preparation-of-nylon-66-1.html">Preparation of nylon 6,6</a></li><li><a href="../19343/determination-of-vitamin-c-content--1.html">Determination of vitamin C content </a></li><li><a href="../19342/hydrolysis-of-starch--1.html">Hydrolysis of starch </a></li><li><a href="../19159/preparation-purification-of-aspirin--1.html">Preparation & purification of aspirin </a></li></ul></li><li><a href="../18851/ict-in-practical-work-1.html" class="father">ICT in practical work</a><ul class="level-2"><li><a href="../18852/data-logging--1.html">Data logging </a></li><li><a href="../18853/software-for-graph-plotting--1.html">Software for graph plotting </a></li><li><a href="../18854/spreadsheets-for-data-processing--1.html">Spreadsheets for data processing </a></li><li><a href="../18855/databases-1.html">Databases</a></li><li><a href="../18856/computer-modelling-simulations--1.html">Computer modelling & simulations </a></li></ul></li><li><a href="../16594/group-4-project-1.html" class="father">Group 4 Project</a><ul class="level-2"><li><a href="../16595/practicalities-1.html">Practicalities</a></li><li><a href="../16596/reflective-statement--2.html">Reflective statement </a></li></ul></li><li><a href="../16666/a-new-laboratory-1.html">A new laboratory?</a></li></ul></li><li><a href="../16284/exams-1.html">Exams</a><ul class="level-1"><li><a href="../16286/essential-facts-1.html" class="father">Essential Facts</a><ul class="level-2"><li><a href="../16287/objectives-command-terms-1.html">Objectives & command terms</a></li><li><a href="../16288/grade-descriptors-1.html">Grade descriptors</a></li><li><a href="../16289/grade-boundaries-1.html">Grade boundaries</a></li></ul></li><li><a href="../16302/paper-1-multiple-choice-1.html" class="father">Paper 1 (Multiple Choice)</a><ul class="level-2"><li><a href="../16303/advice-to-students-paper-1-1.html">Advice to students (Paper 1)</a></li><li><a href="../31515/practice-paper-1-exams-1.html">Practice Paper 1 exams</a></li></ul></li><li><a href="../16305/paper-2-1.html" class="father">Paper 2</a><ul class="level-2"><li><a href="../16306/advice-to-students-paper-2-1.html">Advice to students (Paper 2)</a></li><li><a href="../16307/areas-of-difficulty-1.html">Areas of difficulty</a></li></ul></li><li><a href="../16313/paper-3--1.html" class="father">Paper 3 </a><ul class="level-2"><li><a href="../16314/advice-to-students-paper-3-1.html">Advice to students (Paper 3)</a></li><li><a href="../16342/data-response-questions-1.html">Data response questions</a></li><li><a href="../20054/experimental-work-questions-1.html">Experimental work questions</a></li></ul></li><li><a href="../16324/the-examination-process-1.html" class="father">The examination process</a><ul class="level-2"><li><a href="../16316/setting-the-exam-papers-1.html">Setting the exam papers</a></li><li><a href="../16317/predicted-grades-1.html">Predicted grades</a></li><li><a href="../16318/marking-the-papers-1.html">Marking the papers</a></li><li><a href="../16319/commenting-on-the-exams-1.html">Commenting on the exams</a></li><li><a href="../16320/grade-awarding-1.html">Grade Awarding</a></li><li><a href="../16321/enquiry-upon-results-1.html">Enquiry upon results</a></li><li><a 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Section A questions</a></li><li><a href="../17792/sl-questions-on-the-options-1.html">SL Questions on the options</a></li><li><a href="../24897/sl-quizzes-on-option-sub-topics--1.html">SL Quizzes on option sub-topics </a></li><li><a href="../17785/hl-multiple-choice-tests-on-individual-topics-1.html">HL Multiple choice tests on individual topics</a></li><li><a href="../24352/hl-multiple-choice-quizzes-on-sub-topics-1.html">HL Multiple choice &#039;quizzes&#039; on sub-topics</a></li><li><a href="../31520/hl-practice-paper-1-exams--1.html">HL Practice Paper 1 exams </a></li><li><a href="../17787/hl-questions-on-each-sub-topic--1.html">HL Questions on each sub-topic </a></li><li><a href="../20428/hl-paper-3-section-a-questions-1.html">HL Paper 3 Section A questions</a></li><li><a href="../17793/hl-questions-on-the-options-1.html">HL Questions on the options</a></li><li><a href="../24973/hl-quizzes-on-option-sub-topics-1.html">HL Quizzes on option sub-topics</a></li><li><a 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title="Equilibrium law ">Equilibrium law </a></li><ul class="level-3 "><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../24660/mc-test-the-equilibrium-law-1.html" title="MC test: The equilibrium law">MC test: The equilibrium law</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../40961/equilibrium-law-questions-1.html" title="Equilibrium law questions">Equilibrium law questions</a></li></ul></ul><li class=" parent" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18120/topics-8-18--1.html" title="Topics 8 & 18 ">Topics 8 & 18 </a></li><ul class="level-2 "><li class=" parent" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../18124/theories-of-acids-bases--1.html" title="Theories of acids & bases ">Theories of acids & bases </a></li><ul class="level-3 "><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right 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href="../40964/properties-of-acids-bases-questions-1.html" title="Properties of acids & bases questions">Properties of acids & bases questions</a></li></ul><li class=" parent" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../18140/ph-scale-1.html" title="pH scale">pH scale</a></li><ul class="level-3 "><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../24668/mc-test-the-ph-scale-1.html" title="MC test: The pH scale">MC test: The pH scale</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../40971/ph-scale-questions-1.html" title="pH scale questions">pH scale questions</a></li></ul><li class=" parent" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../18152/strong-weak-acids-bases-1.html" title="Strong & weak acids & bases">Strong & weak acids & bases</a></li><ul class="level-3 "><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../24670/mc-test-strong-weak-acids-bases-1.html" title="MC test: Strong & weak acids & bases">MC test: Strong & weak acids & bases</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../40972/strong-weak-acid-bases-questions-1.html" title="Strong & weak acid & bases questions">Strong & weak acid & bases questions</a></li></ul><li class=" parent" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../18156/acid-deposition-1.html" title="Acid deposition">Acid deposition</a></li><ul class="level-3 "><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../24674/mc-test-acid-deposition-1.html" title="MC test: Acid deposition">MC test: Acid deposition</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../40983/acid-deposition-questions-1.html" title="Acid deposition questions">Acid deposition questions</a></li></ul><li class=" parent" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../18160/lewis-acids-bases-1.html" title="Lewis acids & bases">Lewis acids & bases</a></li><ul class="level-3 "><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../24710/mc-test-lewis-acids-bases-1.html" title="MC test: Lewis acids & bases">MC test: Lewis acids & bases</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../40986/lewis-acids-bases-questions-1.html" title="Lewis acids & bases questions">Lewis acids & bases questions</a></li></ul><li class=" parent" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../18250/acid-base-calculations-1.html" title="Acid base calculations">Acid base calculations</a></li><ul class="level-3 "><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a 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</a></li></ul></ul><li class=" parent" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18350/topics-9-19-1.html" title="Topics 9 & 19">Topics 9 & 19</a></li><ul class="level-2 "><li class=" parent" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../18365/oxidation-reduction-1.html" title="Oxidation & reduction">Oxidation & reduction</a></li><ul class="level-3 "><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../24725/mc-test-oxidation-reduction-1.html" title="MC test: Oxidation & reduction">MC test: Oxidation & reduction</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../41033/oxidation-reduction-questions-1--1.html" title="Oxidation & reduction questions (1) ">Oxidation & reduction questions (1) </a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a 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questions</a></li></ul></ul><li class=" parent" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../18475/topics-10-20--1.html" title="Topics 10 & 20 ">Topics 10 & 20 </a></li><ul class="level-2 "><li class=" parent" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../18497/fundamentals-of-organic-chemistry--1.html" title="Fundamentals of organic chemistry ">Fundamentals of organic chemistry </a></li><ul class="level-3 "><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../24749/mc-test-fundamentals-of-organic-chemistry-1.html" title="MC test: Fundamentals of organic chemistry">MC test: Fundamentals of organic chemistry</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../41111/fundamentals-of-organic-chemistry-1-questions-1.html" title="Fundamentals of organic chemistry (1) questions">Fundamentals of organic chemistry (1) questions</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../41112/fundamentals-of-organic-chemistry-2-questions-1.html" title="Fundamentals of organic chemistry (2) questions">Fundamentals of organic chemistry (2) questions</a></li></ul><li class=" parent" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../18597/alkanes-alkenes-addition-polymers-1.html" title="Alkanes, alkenes & addition polymers">Alkanes, alkenes & addition polymers</a></li><ul class="level-3 "><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../24750/mc-test-alkanes-alkenes-addition-polymers-1.html" title="MC test: Alkanes, alkenes & addition polymers">MC test: Alkanes, alkenes & addition polymers</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../41121/alkanes-questions-1.html" title="Alkanes questions">Alkanes questions</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../41124/alkenes-questions-1.html" title="Alkenes questions">Alkenes questions</a></li></ul><li class=" parent" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../18741/alcohols--1.html" title="Alcohols ">Alcohols </a></li><ul class="level-3 "><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../24772/mc-test-alcohols-1.html" title="MC test: Alcohols">MC test: Alcohols</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../41125/alcohols-questions-1.html" title="Alcohols questions">Alcohols questions</a></li></ul><li class=" parent" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../18742/halogenoalkanes-benzene--1.html" title="Halogenoalkanes & benzene ">Halogenoalkanes & benzene </a></li><ul class="level-3 "><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../24797/mc-test-halogenoalkanes-benzene-1.html" title="MC test: Halogenoalkanes & benzene">MC test: Halogenoalkanes & benzene</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../41130/halogenoalkanes-benzene-questions-1.html" title="Halogenoalkanes & benzene questions">Halogenoalkanes & benzene questions</a></li></ul><li class=" parent" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../18762/nucleophilic-substitution--1.html" title="Nucleophilic substitution ">Nucleophilic substitution </a></li><ul class="level-3 "><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../24757/mc-test-nucleophilic-substitution-1.html" title="MC test: Nucleophilic substitution">MC test: Nucleophilic substitution</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../41138/nucleophilic-substitution-questions-1.html" title="Nucleophilic substitution questions">Nucleophilic substitution questions</a></li></ul><li class=" parent" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../18766/electrophilic-addition--1.html" title="Electrophilic addition ">Electrophilic addition </a></li><ul class="level-3 "><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../24805/mc-test-electrophilic-addition-electrophilic-substitution-reacti-2.html" title="MC test: Electrophilic addition & electrophilic substitution reactions">MC test: Electrophilic addition & electrophilic substitution reactions</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../41148/electrophilic-addition-questions-1.html" title="Electrophilic addition questions">Electrophilic addition questions</a></li></ul><li class=" parent" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../18780/electrophilic-substitution--2.html" title="Electrophilic substitution ">Electrophilic substitution </a></li><ul class="level-3 "><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../41149/electrophilic-substitution-questions-1.html" title="Electrophilic substitution questions">Electrophilic substitution questions</a></li></ul><li class=" parent" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../18793/reduction-reactions--1.html" title="Reduction reactions ">Reduction reactions </a></li><ul class="level-3 "><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../24811/mc-test-reduction-reactions-1.html" title="MC test: Reduction reactions">MC test: Reduction reactions</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../41150/reduction-reactions-questions-1.html" title="Reduction reactions questions">Reduction reactions questions</a></li></ul><li class=" parent" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../18797/synthetic-routes--1.html" title="Synthetic routes ">Synthetic routes </a></li><ul class="level-3 "><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../24822/mc-test-synthetic-routes-1.html" title="MC test: Synthetic routes">MC test: Synthetic routes</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../41152/synthetic-routes-questions--1.html" title="Synthetic routes questions ">Synthetic routes questions </a></li></ul><li class=" parent" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../18844/stereoisomerism--1.html" title="Stereoisomerism  ">Stereoisomerism  </a></li><ul class="level-3 "><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../24817/mc-test-stereoisomerism-1.html" title="MC test: Stereoisomerism">MC test: Stereoisomerism</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../41166/stereoisomerism-questions-1.html" title="Stereoisomerism questions">Stereoisomerism questions</a></li></ul></ul><li class=" parent" style="padding-left: 14px"><i class="expander fa fa-caret-right "></i><a href="../17285/topics-11-21--1.html" title="Topics 11 & 21 ">Topics 11 & 21 </a></li><ul class="level-2 "><li class=" parent" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../17276/uncertainty-errors--1.html" title="Uncertainty & errors ">Uncertainty & errors </a></li><ul class="level-3 "><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../24818/mc-test-uncertainties-errors-1.html" title="MC test: Uncertainties & errors">MC test: Uncertainties & errors</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../38869/uncertainty-error-questions--1.html" title="Uncertainty & error questions ">Uncertainty & error questions </a></li></ul><li class=" parent" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../15014/graphical-techniques-1.html" title="Graphical techniques">Graphical techniques</a></li><ul class="level-3 "><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../24819/mc-test-graphical-techniques-1.html" title="MC test: Graphical techniques">MC test: Graphical techniques</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../39387/graphical-techniques-questions--1.html" title="Graphical techniques questions ">Graphical techniques questions </a></li></ul><li class=" parent" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../18968/spectroscopic-identification-of-organic-compounds-1.html" title="Spectroscopic identification of organic compounds">Spectroscopic identification of organic compounds</a></li><ul class="level-3 "><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../24820/mc-test-spectroscopic-identification-of-organic-compounds--1.html" title="MC test: Spectroscopic identification of organic compounds ">MC test: Spectroscopic identification of organic compounds </a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../39388/index-of-hydrogen-deficiency-questions-1.html" title="Index of hydrogen deficiency questions">Index of hydrogen deficiency questions</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../39351/identification-from-spectra-question-1-1.html" title="Identification from spectra - Question 1">Identification from spectra - Question 1</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../39353/identification-from-spectra-question-2-1.html" title="Identification from spectra - Question 2">Identification from spectra - Question 2</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../39354/identification-from-spectra-question-3-1.html" title="Identification from spectra - Question 3">Identification from spectra - Question 3</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../39355/identification-from-spectra-question-4-1.html" title="Identification from spectra - Question 4">Identification from spectra - Question 4</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../39356/identification-from-spectra-question-5-1.html" title="Identification from spectra - Question 5">Identification from spectra - Question 5</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../39357/identification-from-spectra-question-6-1.html" title="Identification from spectra - Question 6">Identification from spectra - Question 6</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../39358/identification-from-spectra-question-7-1.html" title="Identification from spectra - Question 7">Identification from spectra - Question 7</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../39359/identification-from-spectra-question-8-1.html" title="Identification from spectra - Question 8">Identification from spectra - Question 8</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../39360/identification-from-spectra-question-9-1.html" title="Identification from spectra - Question 9">Identification from spectra - Question 9</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../39361/identification-from-spectra-question-10-1.html" title="Identification from spectra - Question 10">Identification from spectra - Question 10</a></li></ul><li class=" parent" style="padding-left: 28px"><i class="expander fa fa-caret-right "></i><a href="../19027/spectroscopic-identification-of-organic-compounds-ahl--1.html" title="Spectroscopic identification of organic compounds (AHL) ">Spectroscopic identification of organic compounds (AHL) </a></li><ul class="level-3 "><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../24821/mc-test-spectroscopic-identification-of-organic-compounds-ahl-1.html" title="MC test: Spectroscopic identification of organic compounds (AHL)">MC test: Spectroscopic identification of organic compounds (AHL)</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../39375/identification-from-spectra-question-11-1.html" title="Identification from spectra - Question 11">Identification from spectra - Question 11</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../39376/identification-from-spectra-question-12-1.html" title="Identification from spectra - Question 12">Identification from spectra - Question 12</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../39377/identification-from-spectra-question-13-1.html" title="Identification from spectra - Question 13">Identification from spectra - Question 13</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../39378/identification-from-spectra-question-14-1.html" title="Identification from spectra - Question 14">Identification from spectra - Question 14</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../39379/identification-from-spectra-question-15-1.html" title="Identification from spectra - Question 15">Identification from spectra - Question 15</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../39380/identification-from-spectra-question-16-1.html" title="Identification from spectra - Question 16">Identification from spectra - Question 16</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../39381/identification-from-spectra-question-17-1.html" title="Identification from spectra - Question 17">Identification from spectra - Question 17</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a href="../39382/identification-from-spectra-question-18-1.html" title="Identification from spectra - Question 18">Identification from spectra - Question 18</a></li><li class="" style="padding-left: 42px"><i class="expander fa fa-caret-right "></i><a 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</div><section id="main-content"><div id="toc-1672972901" class="toc"><a href="#" class="toc-switcher" title="Show table of contents"><small><i class="fa fa-reorder"></i> Table of contents <span class="pull-right"><i class="fa fa-chevron-down"></i></span></small></a></div><h1><img class="ico" src="../../../img/icons/higher-1.png"> 15.2 Entropy &amp; spontaneity (4 hours)</h1><div class="pinkBg"><div><h2>Pause for thought</h2><p>Entropy is paradoxically probably one of the hardest and one of the easiest topics to teach! Hardest because a full understanding of entropy really requires knowledge of statistical thermodynamics; easiest because at this level it can be related simply to the idea of disorder and the questions asked in the examination are usually very straightforward.</p><p><img alt="" class="left noborder" src="../../../ib/chemistry/images/2014%20Core%20%26%20AHL/Topics-5---15/ice-water.png" style="width: 259px; height: 388px;" title="When ice melts and cools the surrounding water will the overall entropy change be positive or negative?"></p><p>If you tell your students that &#39;nature tends to disorder&#39; which is a very simplified form of the second law of thermodynamics (The total entropy change of an isolated system must be positive) this will generally suffice. It is actually better to explain that it refers to the distribution of available energy among the particles. The more ways the energy can be distributed the higher the entropy. However it can be quite difficult to explain why complex, highly ordered arrangements of molecules such as ice crystals form when water is cooled or even why humans exist. They need to understand the difference between an isolated system and a subsystem. While the entropy change within a subsystem (ice or humans) may become negative (i.e. more ordered) the total entropy change within the larger isolated system will be positive.</p><p style="text-align: center; "><em>&Delta;S</em><sub>total</sub> = <em>&Delta;S</em><sub>subsystem</sub> + <em>&Delta;S</em><sub>surroundings</sub></p><p><br>Consider what happens when ice is added to water to cool a drink (left). When the ice melts it becomes more disordered (<em>&Delta;S</em>&gt; 0) but the surrounding water in the glass becomes lower in temperature so therefore becomes more ordered (<em>&Delta;S</em>&lt; 0). The heat gained by the ice must be equal to the heat lost by the water but overall the increase in disorder due to the ice melting is greater than the increase in order due to the surrounding water cooling.</p><p>The word &#39;spontaneous&#39; provides a good example to use when discussing the importance of the correct use of language in chemistry. Language is one of the eight ways of knowing addressed in the TOK syllabus. Sometimes when students have difficulty answering a question it is because they have not understood the language used in the question rather than the underlying chemical theory (see <a href="../3510/language-of-chemistry.html" title="IB Core » Theory of Knowledge » Why TOK &amp; Chemistry? » Language of Chemistry">Language of Chemistry</a>). In everyday English spontaneous means &#39;off the cuff&#39; or carrying out an action or thought without prior preparation or considering all the consequences beforehand. In Chemistry it has a very different and highly specific meaning. According to sub-topic 15.2 all a Higher Level IB student needs to know is that a reaction will be spontaneous when <em>&Delta;G</em><img class="ico" src="http://www.thinkib.net/img/icons/underground.png"> is negative - but what does this really mean?</p><p><img alt="" class="right noborder" height="297" src="../../../ib/chemistry/images/Core%20and%20AHL/Energetics/Damien%20Hirst%20diamond%20skull.jpg" title="Damien Hirst's Diamond skull which sold for US$100 million. Luckily it is kinetically stable even though it is thermodynamically unstable." width="235">A spontaneous reaction is one that once initiated <strong>can</strong> proceed in a given direction without needing to be driven by the input of an external source of energy. In other words a spontaneous reaction releases free energy - that is energy that is available to do work<sup>1</sup>. It does not necessarily mean the reaction must be exothermic or that there must be an increase in entropy as it depends upon a combination of both of these factors according to the equation <em>&Delta;G</em><img class="ico" src="http://www.thinkib.net/img/icons/underground.png"> = <em>&Delta;H</em><img class="ico" src="http://www.thinkib.net/img/icons/underground.png"> &ndash; <em>T&Delta;S</em><img class="ico" src="http://www.thinkib.net/img/icons/underground.png">.</p><p>Notice the use of the word &#39;<strong>can</strong>&#39; rather than &#39;<strong>will</strong>&#39; in the definition. In English spontaneous usually implies something done quite quickly. In chemistry there is no concept of time in the use of the word spontaneous. It says nothing about the rate of the reaction. Often a spontaneous reaction may not proceed at any measurable rate as the activation energy is so high. A good example is the combustion of carbon. Diamonds are pure carbon. In 2007 the artist Damien Hirst made a skull of diamonds (right) called &#39;For the love of God&#39;. Luckily for the group that bought it for one hundred million US dollars diamonds are extremely stable kinetically in air even though, as <em>&Delta;G</em> for the combustion of carbon is negative, they are thermodynamically unstable and spontaneously burn to form carbon dioxide.</p><hr class="hidden"><p><sup>1.</sup> Strictly speaking it is the ability to do external work. This is because &Delta;<em>H</em> is the enthalpy change at constant pressure and if there is a volume increase then internal work is done as the volume expands. This is beyond the syllabus as the IB does not distinguish between &Delta;<em>H</em> and the enthalpy change at constant volume, &Delta;<em>U</em>.</p><hr class="hidden"></div></div><hr class="hidden"><div class="box"><h2>Nature of Science</h2><p>The idea of entropy has evolved over the years due to developments in statistics and probability. This is an example of how theories develop and can be superseded over time.</p><hr class="hidden"></div><hr class="hidden"><div class="box"><table align="left" border="0" cellpadding="10" cellspacing="0"><tbody><tr><td style="width: 50%;" valign="top"><h3><b><span style="font-weight: normal; "></span></b></h3><div class="yellowBg"><div><h2><b><span style="font-weight: normal; "><strong>Learning outcomes</strong></span></b></h2><p><span style="font-weight: normal; ">After studying this topic students should be able to:</span></p><p><b><span style="font-weight: normal; "><strong>Understand</strong></span></b></p><ul><li>Entropy (<em>S</em>) is related to the distribution of available energy among the relevant particles. The more ways the energy can be distributed the higher the entropy.</li><li>The Gibbs free energy change (<em>&Delta;G</em>) is the energy obtained from a chemical reaction that is available to do work. It is related to the change in enthalpy (<em>&Delta;H</em>), the change in entropy (<em>&Delta;S</em>), and the absolute temperature (<em>T</em>).</li><li>Under the same conditions the entropy of a gas is greater than the entropy of a liquid which in turn is greater than the entropy of a solid.</li></ul><p><strong>Apply their knowledge to:</strong></p><ul><li>Predict, by considering the states of the reactants and products, whether a change will result in an increase or decrease in entropy.</li><li>Calculate entropy changes (<em>&Delta;S</em>) from standard entropy values (<em>S</em><sup>⦵</sup>).</li><li>Apply the equation <em>&Delta;G</em><sup>⦵</sup> = <em>&Delta;H</em><sup>⦵</sup> &ndash; <em>T&Delta;S</em><sup>⦵</sup> to predict spontaneity and calculate the various conditions of enthalpy and temperature that will affect this.</li><li>Relate the value and sign of &Delta;<em>G</em> to the position of equilibrium of a reaction.</li></ul></div></div></td><td style="width: 50%;" valign="top"><h4><b><span style="font-weight: normal; "></span></b></h4><div class="yellowBg"><div><h4><b><span style="font-weight: normal; "><strong>Clarification notes</strong></span></b></h4><p>Various reaction conditions that affect the value and sign of <em>&Delta;G</em> should be examined.<br><em>&Delta;G</em> provides a convenient way to take into account both the direct entropy change resulting from the transformation of the chemicals, and the indirect entropy change of the surroundings as a result of the gain/loss of heat energy.<br>Relevant thermodynamic data can be found in Section 12 of the data booklet.</p><hr class="hidden"><h4><strong>International-mindedness</strong></h4><p>The UN sustainable energy initiative has the goal of doubling of global sustainable energy resources by 2030.</p></div></div></td></tr></tbody></table></div><hr class="hidden"><div class="box"><table align="left" border="0" cellpadding="10" cellspacing="0"><tbody><tr><td style="width: 50%;" valign="top"><h2><span style=""><b><span style="font-weight: normal;"><strong>Teaching tips</strong></span></b></span></h2><p>My teaching room has a door leading to a resource room. I like to start entropy by asking students why, if one room was filled with oxygen and the other with nitrogen, the two gases mix when the door is opened even though no enthalpy change takes place. Alternatively, could the air currently in the rooms arrange itself so that all the nitrogen went to one room and all the oxygen stayed in the other room? I then relate the idea of disorder to all the possible random combinations in the ways the individual molecule making up the air disperse. In theory one combination is that all the nitrogen molecules would be in one room and all the oxygen molecules in the other. The chance of this one specific possibility is infinitesimally small and is never likely to happen and even if it did it would only be for a minute fraction of a second.</p><p>Discuss with them the ideas of order and disorder and the concept of subsystems and total isolated systems. They should understand that, unlike enthalpy (<em>H<img class="ico" src="http://www.thinkib.net/img/icons/underground.png"></em>) where only the change in enthalpy (<em>&Delta;H</em><em><img class="ico" src="http://www.thinkib.net/img/icons/underground.png"></em>) can be measured, standard entropy (<em>S<img class="ico" src="http://www.thinkib.net/img/icons/underground.png"></em>) values of individual substances can be measured. For IB purposes it is assumed that the enthalpy values of substances are independent of temperature.</p><p>At this level impress upon them that changes of state usually cause the largest entropy changes. For this reason, most IB questions where they ask whether the change is positive or negative involve either changes of state or an increase or decrease in the total number of molecules present.</p><p>It is difficult to do much meaningful IB practical work with entropy. You could tell them to tidy up their room at home - it is a lot easier to make it untidy (more disordered) than it is to tidy it!</p><p>Up to this point students tend to only think of the energy of a reaction in terms of enthalpy change. I like to introduce spontaneity by returning to the example of why gases mix (or do not unmix) even though there is no enthalpy change. This impresses upon them that there are other driving forces to a reaction or process other than just an enthalpy change. The concept of free energy - the energy available to do work - can then be explained.</p><p>The key to this sub-topic is the relationship <em>&Delta;G</em><sup>⦵</sup> = <em>&Delta;H</em><sup>⦵ </sup>&ndash; <em>T&Delta;S</em><sup>⦵</sup> and it is worth stressing that this is one of the most important relationships in the whole of Chemistry. Even so, many students get it wrong when they try to use it as they ignore the fact that the units of enthalpy are <strong>kJ mol<sup>-1</sup></strong> whereas the units of entropy are <strong>J K<sup>-1</sup> </strong><strong>mol</strong><sup><strong>-1</strong></sup><sup>. </sup>The K<sup>-1</sup> is easily taken care of by quoting the temperature as its absolute (or Kelvin) value. The problem usually is that students forget to either convert the enthalpy change into J mol<sup>-1</sup> by multiplying by 1000 or convert the entropy change to kJ K<sup>-1</sup> mol<sup>-1</sup> by dividing by 1000 before substituting the values into the equation (see <a href="../31240/understanding-and-using-g-.html" title="Exams » Paper 2 » Areas of difficulty » Understanding and using Δ&lt;em&gt;G &lt;/em&gt;">Understanding and using &Delta;G</a>).</p><p>Get them to work out all the possibilities for when <em>&Delta;H</em><img class="ico" src="../../../img/icons/underground.png"> is positive or negative and for when <em>&Delta;S</em><img class="ico" src="../../../img/icons/underground.png"> is positive or negative. They should see there are two cases where the sign of <em>&Delta;G</em><img class="ico" src="../../../img/icons/underground.png"> could be either positive or negative depending upon the value of <em>T</em>. You can then give them practice with questions which determine at what temperature a reaction will become spontaneous.</p><p>Stress that just because <em>&Delta;G</em><img class="ico" src="../../../img/icons/underground.png"> is negative it does not mean the reaction will occur at a fast rate. Kinetic stability is very different to thermodynamic stability and depends upon the size of the activation energy.</p><p>The relationship between <em>&Delta;G</em><img class="ico" src="../../../img/icons/underground.png"> and the equilibrium constant, <em>K</em><sub>c</sub>, is probably best left until you teach topic 17.1.</p><hr class="hidden"></td><td style="width: 50%;" valign="top"><h4><b><span style="font-weight: normal; "><strong>Study guide</strong></span></b></h4><p style="margin: 0px 0px 1em; padding: 0px; color: rgb(0, 0, 0); font-size: 1em;"><img alt="" src="../../../ib/chemistry/images/2014%20Basic%20information/New%20cover.jpg" style="width: 67px; height: 96px;"></p><p style="margin: 0px 0px 1em; padding: 0px; color: rgb(0, 0, 0); font-size: 1em;"></p><p style="margin: 0px 0px 1em; padding: 0px; color: rgb(0, 0, 0); font-size: 1em;"><b><span style="font-weight: normal;">Page </span></b><span style="font-weight: normal;">43</span><b><span style="font-weight: normal;"> -</span></b><span style="font-weight: normal;"> 44</span></p><hr class="hidden"><h2>Questions</h2><p>For ten &#39;quiz&#39; multiple choice questions with the answers explained see <a href="../24608/mc-test-entropy-spontaneity-1.html" title="Core &amp; AHL » Teaching each topic &amp; sub-topic » Topics 5 &amp; 15 » Entropy &amp; spontaneity » MC test: Entropy &amp; spontaneity">MC test: Entropy &amp; spontaneity</a>.</p><p style="margin: 0px 0px 1em; padding: 0px; color: rgb(0, 0, 0); font-size: 1em;">For short-answer questions which can be set as an assignment for a test, homework or given for self study together with model answers see <a href="../39650/entropy-spontaneity-questions--1.html" title="Core &amp; AHL » Teaching each topic &amp; sub-topic » Topics 5 &amp; 15 » Entropy &amp; spontaneity » Entropy &amp; spontaneity questions ">Entropy &amp; spontaneity questions</a>.</p><hr class="hidden"><h4><span style=""><b><span style="font-weight: normal;"><strong>Vocabulary list</strong></span></b></span></h4><p>Entropy, <em>S</em><br>Standard entropy change, <em>&Delta;S</em><sup>⦵</sup><br>disorder<br>isolated system<br>subsystem<br>Gibbs free energy change, <em>&Delta;G</em><sup>⦵</sup><br>spontaneous<br>spontaneity<br>thermodynamically stable<br>kinetically stable</p><hr class="hidden"><h4><span style="color: rgb(0, 51, 102); font-family: 'Arial Narrow', Arial, Helvetica, sans-serif; font-size: 17px; font-weight: bold; "><b><span style="font-weight: normal;"><strong>IM, TOK, &#39;Utilization&#39; etc.</strong></span></b></span></h4><p>See <a href="../17270/topics-5-15--1.html">separate page</a> which covers all of Topic 5 &amp; 15.</p><hr class="hidden"><h2>Practical work</h2><p>Most practicals simply do traditional calorimeter experiments to find &Delta;<em>H</em> for a reaction then use data tables for entropy values to calculate &Delta;<em>G</em>. For example, you could adapt for IB use the&nbsp;<a href="/media/ib/chemistry/files/Topics/Energetics/ThermodynamicsethalpyEntropyGibbsFree.pdf" target="_blank" title="Labs"><img class="ico" src="../../../img/icons/lab-1.png"> Free energy of solvation </a>practical from the University of New Mexico.</p></td></tr></tbody></table></div><hr class="hidden"><div class="greenBg"><h2 id="header-13">Teaching slides</h2><p>Teachers may wish to share these slides with students for learning or for reviewing key concepts.</p><div id="myCarousel-14" class="carousel slide" data-id="261"><!-- Carousel items --><div class="carousel-inner"><div class="active item"><a class="fancy" href="../../../tib-galleries/3-261/1521.png" rel="gallery-261" title=""><img alt="" src="files/tib-galleries/3-261/1521.png"></a><div class="carousel-caption"><p>Entropy & Spontaneity: </p></div></div><div class="item"><a class="fancy" href="../../../tib-galleries/3-261/1522.png" rel="gallery-261" title=""><img alt="" src="files/tib-galleries/3-261/1522.png"></a><div class="carousel-caption"><p>Entropy & Spontaneity: </p></div></div><div class="item"><a class="fancy" href="../../../tib-galleries/3-261/15231.png" rel="gallery-261" title=""><img alt="" src="files/tib-galleries/3-261/15231.png"></a><div class="carousel-caption"><p>Entropy & Spontaneity: </p></div></div><div class="item"><a class="fancy" href="../../../tib-galleries/3-261/1524.png" rel="gallery-261" title=""><img alt="" src="files/tib-galleries/3-261/1524.png"></a><div class="carousel-caption"><p>Entropy & Spontaneity: </p></div></div><div class="item"><a class="fancy" href="../../../tib-galleries/3-261/1525.png" rel="gallery-261" title=""><img alt="" src="files/tib-galleries/3-261/1525.png"></a><div class="carousel-caption"><p>Entropy & Spontaneity: </p></div></div><div class="item"><a class="fancy" href="../../../tib-galleries/3-261/1526.png" rel="gallery-261" title=""><img alt="" src="files/tib-galleries/3-261/1526.png"></a><div class="carousel-caption"><p>Entropy & Spontaneity: </p></div></div><div class="item"><a class="fancy" href="../../../tib-galleries/3-261/1527.png" rel="gallery-261" title=""><img alt="" src="files/tib-galleries/3-261/1527.png"></a><div class="carousel-caption"><p>Entropy & Spontaneity: </p></div></div><div class="item"><a class="fancy" href="../../../tib-galleries/3-261/152-81.png" rel="gallery-261" title=""><img alt="" src="files/tib-galleries/3-261/152-81.png"></a><div class="carousel-caption"><p>Entropy & Spontaneity: </p></div></div><div class="item"><a class="fancy" href="../../../tib-galleries/3-261/1529.png" rel="gallery-261" title=""><img alt="" src="files/tib-galleries/3-261/1529.png"></a><div class="carousel-caption"><p>Entropy & Spontaneity: </p></div></div><div class="item"><a class="fancy" href="../../../tib-galleries/3-261/15210.png" rel="gallery-261" title=""><img alt="" src="files/tib-galleries/3-261/15210.png"></a><div class="carousel-caption"><p>Entropy & Spontaneity: </p></div></div><div class="item"><a class="fancy" href="../../../tib-galleries/3-261/15211.png" rel="gallery-261" title=""><img alt="" src="files/tib-galleries/3-261/15211.png"></a><div class="carousel-caption"><p>Entropy & Spontaneity: </p></div></div><div class="item"><a class="fancy" href="../../../tib-galleries/3-261/15212.png" rel="gallery-261" title=""><img alt="" src="files/tib-galleries/3-261/15212.png"></a><div class="carousel-caption"><p>Entropy & Spontaneity: </p></div></div></div><!-- Carousel nav --><a class="carousel-control left" href="#myCarousel-14" data-slide="prev">&lsaquo;</a><a class="carousel-control right" href="#myCarousel-14" data-slide="next">&rsaquo;</a><div class="tib-indicators"><img class="" title="Click to view" style="margin: 10px 4px; width: 48px; height: 48px;" alt="" src="files/tib-galleries/3-261/1521-thumb128.jpg"><img class="" title="Click to view" style="margin: 5px 4px; width: 48px; height: 48px;" alt="" src="files/tib-galleries/3-261/1522-thumb128.jpg"><img class="" title="Click to view" style="margin: 5px 4px; width: 48px; height: 48px;" alt="" src="files/tib-galleries/3-261/15231-thumb128.jpg"><img class="" title="Click to view" style="margin: 5px 4px; width: 48px; height: 48px;" alt="" src="files/tib-galleries/3-261/1524-thumb128.jpg"><img class="" title="Click to view" style="margin: 5px 4px; width: 48px; height: 48px;" alt="" src="files/tib-galleries/3-261/1525-thumb128.jpg"><img class="" title="Click to view" style="margin: 5px 4px; width: 48px; height: 48px;" alt="" src="files/tib-galleries/3-261/1526-thumb128.jpg"><img class="" title="Click to view" style="margin: 5px 4px; width: 48px; height: 48px;" alt="" src="files/tib-galleries/3-261/1527-thumb128.jpg"><img class="" title="Click to view" style="margin: 5px 4px; width: 48px; height: 48px;" alt="" src="files/tib-galleries/3-261/152-81-thumb128.jpg"><img class="" title="Click to view" style="margin: 5px 4px; width: 48px; height: 48px;" alt="" src="files/tib-galleries/3-261/1529-thumb128.jpg"><img class="" title="Click to view" style="margin: 5px 4px; width: 48px; height: 48px;" alt="" src="files/tib-galleries/3-261/15210-thumb128.jpg"><img class="" title="Click to view" style="margin: 5px 4px; width: 48px; height: 48px;" alt="" src="files/tib-galleries/3-261/15211-thumb128.jpg"><img class="" title="Click to view" style="margin: 5px 4px; width: 48px; height: 48px;" alt="" src="files/tib-galleries/3-261/15212-thumb128.jpg"></div></div><p>&nbsp;&nbsp;</p></div><hr class="hidden"><div class="blueBg"><h2><span style="font-weight: bold;">Other resources</span></h2><p><strong>1.</strong> For a bit of fun how about &#39;Entropy set to music&#39; by Stevethedinosaur.</p><p style="text-align: center; "><iframe allowfullscreen="" frameborder="0" height="280" src="//www.youtube.com/embed/5KIhDVLbMeY?rel=0" width="340"></iframe></p><p style="text-align: center; "><a href="http://youtu.be/5KIhDVLbMeY">Entropy (1) <img class="ico" src="http://www.thinkib.net/img/icons/video.png"></a></p><hr class="hidden"><p><strong>2.</strong> For a more serious explanation of entropy with a good example using sand and a sandcastle try Professor Brian Cox - taken from his excellent BBC series on the wonders of the universe.</p><p style="text-align: center;"><iframe allowfullscreen="" frameborder="0" height="280" src="//www.youtube.com/embed/uQSoaiubuA0?rel=0" width="360"></iframe></p><p style="text-align: center;"><a href="http://youtu.be/uQSoaiubuA0">Entropy (2) <img class="ico" src="http://www.thinkib.net/img/icons/video.png"></a></p><hr class="hidden"><p><strong>3.</strong> A student giving a tutorial on Gibbs Free Energy. It is an interesting video as the student shows clearly how to work out the change in free entropy for a particular reaction and relates it to the IB definition of spontaneous. However it is clear that there is no actual understanding of what a spontaneous reaction is as there is confusion between kinetic and thermodynamic stability.</p><p style="text-align: center; "><iframe allowfullscreen="" frameborder="0" height="280" src="//www.youtube.com/embed/ECjH1ErqzRU?rel=0" width="360"></iframe></p><p style="text-align: center; "><a href="http://youtu.be/ECjH1ErqzRU">Gibbs free energy (1) <img class="ico" src="../../../img/icons/video-1.png"><span class="anchor" id="video-1" name="video-1">&nbsp;</span></a></p><p style="text-align: center; "></p><p style="text-align: center; "></p><hr class="hidden"><p><strong>4. </strong>A better explanation with some specific example given by Paul Andersen.</p><p style="text-align: center;"><iframe allowfullscreen="" frameborder="0" height="280" src="//www.youtube.com/embed/DPjMPeU5OeM?rel=0" width="360"></iframe></p><p style="text-align: center; "><a href="http://youtu.be/DPjMPeU5OeM">Gibbs free energy (2) <img class="ico" src="../../../img/icons/video-1.png"><span class="anchor" id="video-2" name="video-2">&nbsp;</span></a></p><hr class="hidden"><p style="text-align: center; "></p><p><strong>5. </strong>If your students can follow the conversation as he speaks very fast this crashcourse video covers most of what is needed for understanding entropy at IB level.</p><p style="text-align: center;"><iframe allowfullscreen="" frameborder="0" height="280" src="//www.youtube.com/embed/ZsY4WcQOrfk?rel=0" width="360"></iframe></p><p style="text-align: center;"><a href="https://youtu.be/ZsY4WcQOrfk" target="_blank" title="Videos"><img class="ico" src="../../../img/icons/video-1.png"><span class="anchor" id="video-3" name="video-3">&nbsp;</span> Entropy (3)</a></p><hr class="hidden"><p style="text-align: center; "></p></div></section></article><section id="media-extras"><div class="page-actions no-print navbar inline hidden-desktop"><div class="navbar-inner"><ul class="nav"><li><a class="presentation" href="#" onclick="return false;"><i class="fa fa-desktop"></i></a></li><li><a class="print-section-blog" href="#" onclick="return false;"><i class="fa fa-print"></i></a></li><li><a class="page-bookmarker" data-ticket="IB Docs (2) Team" data-pid="17780" href="#" onclick="return false;"><i class="fa fa-star"></i></a></li><li><a class="personal-notes" href="#" onclick="return false;"><i class="fa fa-file-text"></i></a></li><li><a class="" data-toggle="modal" href="#modal-feedback" onclick="return false;"><i class="fa fa-envelope-o"></i></a></li><li class="dropdown"><a class="dropdown-toggle" data-toggle="dropdown" data-target="#" href="#"><i class="fa fa-share-alt"></i></a><ul class="dropdown-menu" role="menu"><li><a class="" target="_blank" title="Share on Twitter" href="https://twitter.com/share?text=%22Entropy+%26+spontaneity++%22+-+via+%40InThinker+%23chemistry%0A&url=https%3A%2F%2Fwww.thinkib.net%2Fchemistry%2Fpage%2F17780%2Fentropy-spontaneity-"><i class="fa fa-twitter-square"></i><span>Twitter</span></a></li><li><a class="" target="_blank" title="Share on Facebook" href="https://www.facebook.com/sharer.php?u=https%3A%2F%2Fwww.thinkib.net%2Fchemistry%2Fpage%2F17780%2Fentropy-spontaneity-&t=Entropy+&+spontaneity++"><i class="fa fa-facebook-square"></i><span>Facebook</span></a></li><li><a class="" href="http://www.linkedin.com/shareArticle?mini=true&url=https%3A%2F%2Fwww.thinkib.net%2Fchemistry%2Fpage%2F17780%2Fentropy-spontaneity-"><i class="fa fa-linkedin-square"></i><span>LinkedIn</span></a></li><li><a class="" href="https://plus.google.com/share?url=https%3A%2F%2Fwww.thinkib.net%2Fchemistry%2Fpage%2F17780%2Fentropy-spontaneity-"><i class="fa fa-google-plus-square"></i><span>Google +</span></a></li><li><a class="" href="mailto:?subject=Entropy & spontaneity  &body=Entropy is paradoxically probably one of the hardest and one of the easiest topics to teach! 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