{"id":12475,"date":"2026-10-03T08:32:20","date_gmt":"2026-10-03T07:32:20","guid":{"rendered":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-12-entropy-and-energetics\/thermodynamic-and-kinetic-stability\/"},"modified":"2026-10-04T23:04:40","modified_gmt":"2026-10-04T22:04:40","slug":"thermodynamic-and-kinetic-stability","status":"publish","type":"page","link":"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-12-entropy-and-energetics\/thermodynamic-and-kinetic-stability\/","title":{"rendered":"Thermodynamic and Kinetic Stability"},"content":{"rendered":"\n<section class=\"ols-revision-page ols-kinetics-page\">\n  <style>\n    .ols-revision-page {\n      --navy: #1C244B;\n      --blue: #2563eb;\n      --soft-blue: #eef4ff;\n      --soft-red: #fff7f7;\n      --soft-purple: #f7f0ff;\n      --soft-green: #f0f7f1;\n      --gold: #c9973a;\n      --grey-text: #667085;\n   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href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-12-entropy-and-energetics\/entropy-and-the-direction-of-change\/\">Entropy and the Direction of Change<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-12-entropy-and-energetics\/calculating-entropy-changes\/\">Calculating Entropy Changes<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-12-entropy-and-energetics\/feasibility-gibbs-energy-and-temperature\/\">Feasibility and Temperature<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-12-entropy-and-energetics\/thermodynamic-and-kinetic-stability\/\">Thermodynamic and Kinetic Stability<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-12-entropy-and-energetics\/lattice-energy-and-born-haber-cycles\/\">Lattice Energy and Born\u2013Haber Cycles<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-12-entropy-and-energetics\/lattice-energy-trends-and-covalent-character\/\">Lattice Energy Trends and Covalent Character<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-12-entropy-and-energetics\/enthalpy-of-solution-and-hydration\/\">Enthalpy of Solution and Hydration<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-12-entropy-and-energetics\/predicting-solubility\/\">Predicting Solubility<\/a>\n      <\/li>\n    <\/ul>\n  <\/div>\n\n  <div class=\"ols-topic-group\">\n    <h4>Other Sections<\/h4>\n\n    <ul class=\"ols-topic-list\">\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-6-energetics\/\">Topic 6 Energetics (AS)<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-11-kinetics\/\">Topic 11 Kinetics<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-8-redox-chemistry-and-groups-1-2-and-7\/8b-groups-1-and-2\/\">Topic 8B Groups 1 and 2<\/a>\n      <\/li>\n      <li>\n        <a href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/core-practicals\/\">Core Practicals<\/a>\n      <\/li>\n    <\/ul>\n  <\/div>\n<\/aside>\n\n<script>\r\n(function() {\r\n  function normalisePath(path) {\r\n    return String(path || '')\r\n      .split('?')[0]\r\n      .split('#')[0]\r\n      .replace(\/\\\/+$\/, '')\r\n      .toLowerCase();\r\n  }\r\n\r\n  function highlightActive() {\r\n    var sidebar = document.querySelector('.ols-sidebar');\r\n    if (!sidebar) return false;\r\n\r\n    var currentPath = normalisePath(window.location.pathname);\r\n    var links = sidebar.querySelectorAll('a[href]');\r\n    var matched = null;\r\n    var matchedLength = 0;\r\n\r\n    sidebar.querySelectorAll('.active, .active-main, .parent-active').forEach(function(item) {\r\n      item.classList.remove('active', 'active-main', 'parent-active');\r\n    });\r\n\r\n    sidebar.querySelectorAll('a[data-ols-disabled-parent=\"1\"], 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<h1>Thermodynamic and Kinetic Stability<\/h1>\n        <p class=\"ols-page-intro\">A concise revision guide to the difference between a reaction that cannot happen and one that is feasible but too slow to notice: thermodynamic stability, kinetic stability, why a large activation energy stops a feasible reaction, and the limits of predictions made from entropy and Gibbs energy.<\/p>\n        <div class=\"ols-badges\">\n<div class=\"ols-badge\">Exam board: Edexcel International<\/div>\n<div class=\"ols-badge\">Unit 4: WCH14\/01<\/div>\n<div class=\"ols-badge\">Topic 12: Entropy and Energetics<\/div>\n<\/div>\n        <div class=\"ols-author\">\n\n    <img decoding=\"async\"\n      class=\"ols-author-avatar-img\"\n      src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/05\/Author-Profile.jpeg\"\n      alt=\"Dr. Mohammed Al-Fatah\"\n    >\n\n    <div class=\"ols-author-content\">\n\n      <h2 class=\"ols-author-title\">\n        Written by: Dr. Mohammed Al-Fatah\n      <\/h2>\n\n      <p class=\"ols-author-description\">\n        Chemistry specialist revision notes for A Level Chemistry.\n      <\/p>\n\n      <a class=\"ols-linkedin-pill\" href=\"https:\/\/www.linkedin.com\/in\/doctormohammedfatah\/\" target=\"_blank\" rel=\"noopener noreferrer\">\n        <svg class=\"ols-linkedin-icon\" viewBox=\"0 0 24 24\" fill=\"currentColor\" aria-hidden=\"true\">\n          <path d=\"M4.98 3.5C4.98 4.88 3.86 6 2.48 6S0 4.88 0 3.5 1.12 1 2.48 1s2.5 1.12 2.5 2.5zM.5 8h4V24h-4V8zm7 0h3.8v2.2h.1c.5-.9 1.8-2.2 3.9-2.2 4.2 0 5 2.8 5 6.4V24h-4v-7.6c0-1.8 0-4.2-2.6-4.2s-3 2-3 4v7.8h-4V8z\"\/>\n        <\/svg>\n        View LinkedIn Profile\n      <\/a>\n\n    <\/div>\n\n  <\/div>\n      <\/header>\n\n      <article class=\"ols-note-card\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">1<\/div>\n<h2>Feasible Does Not Mean Fast<\/h2>\n<\/div>\n<p>A positive \u0394S_total tells you that a reaction can happen. It says nothing about <strong>how fast<\/strong> it happens.<\/p>\n<p>The difference between the two questions is one of the most examined ideas in this topic.<\/p>\n<div class=\"ols-table-wrap\">\n<table class=\"ols-table\">\n<thead>\n<tr><th>Example<\/th><th>Why it should happen<\/th><th>What is seen at room temperature<\/th><\/tr>\n<\/thead>\n<tbody>\n<tr><td><strong>A mixture of hydrogen and oxygen<\/strong><\/td><td>\u0394G = \u2212474 kJ mol\u207b\u00b9 for 2H\u2082(g) + O\u2082(g) \u2192 2H\u2082O(l), about as feasible as a reaction gets<\/td><td>the mixture can be kept for years without any water forming<\/td><\/tr>\n<tr><td><strong>Petrol in an open can in the air<\/strong><\/td><td>burning in air is feasible<\/td><td>it does not burn<\/td><\/tr>\n<tr><td><strong>Diamond<\/strong><\/td><td>slightly higher Gibbs energy than graphite: \u0394G = \u22123 kJ mol\u207b\u00b9 for diamond \u2192 graphite at 298 K<\/td><td>every diamond should be turning into graphite, and none noticeably does<\/td><\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p>In each case the reaction is feasible but so slow at room temperature that it does not appear to happen at all.<\/p>\n<h3>The energy barrier<\/h3>\n<p>The reason is the <strong>activation energy<\/strong>, E\u2090. \u0394S_total and \u0394G compare the reactants with the products; they say nothing about the energy barrier between them.<\/p>\n<p>For hydrogen and oxygen:<\/p>\n<ol>\n<li>The molecules must collide with enough energy to break the H\u2013H and O=O bonds before any water can form.<\/li>\n<li>At room temperature almost no collisions have that energy.<\/li>\n<li>A spark supplies it locally, and the heat released then supplies it for the rest: the mixture explodes.<\/li>\n<\/ol>\n<p>Thermodynamics said the reaction could happen; kinetics decided when.<\/p>\n<div class=\"ols-figure-card ols-zoom-pop\">\n<div class=\"ols-figure-image\">\n<a class=\"ols-image-fullscreen-link\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/09\/entropy-t12-14-feasiblefast.jpg\" target=\"_blank\" rel=\"noopener\" aria-label=\"Open image fullscreen\">\n<img decoding=\"async\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/09\/entropy-t12-14-feasiblefast.jpg\" alt=\"Summary poster separating two questions about a reaction, whether it is feasible, decided by thermodynamics, and whether it is fast, decided\" data-fullscreen-src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/09\/entropy-t12-14-feasiblefast.jpg\">\n<\/a>\n<\/div>\n<div class=\"ols-figure-caption\"><p>Two separate questions about any reaction: is it feasible (thermodynamics) and is it fast (kinetics), with the three possible outcomes and what a catalyst can and cannot change.<\/p><\/div>\n<\/div>\n<div class=\"ols-key-box\">\n<p><strong>Key idea:<\/strong> \u0394S_total tells you whether a reaction is feasible, not how fast it goes. Rate depends on the activation energy and the temperature, which do not appear in \u0394S_total.<\/p>\n<\/div>\n<\/article>\n<article class=\"ols-note-card soft\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">2<\/div>\n<h2>Thermodynamic Stability and Kinetic Stability<\/h2>\n<\/div>\n<p>These two situations are described with two different words, and an exam question expects you to choose the right one.<\/p>\n<div class=\"ols-key-box\">\n<p><strong>Definition:<\/strong> A substance or mixture is <strong>thermodynamically stable<\/strong> with respect to a particular change when that change is not feasible: \u0394S_total is negative (\u0394G is positive) at that temperature, so the change cannot happen however long you wait.<\/p>\n<\/div>\n<div class=\"ols-key-box\">\n<p><strong>Definition:<\/strong> A substance or mixture is <strong>kinetically stable<\/strong> when the change is feasible (\u0394S_total positive, \u0394G negative) but so slow that it does not occur at a noticeable rate, because the activation energy is too high for the temperature.<\/p>\n<\/div>\n<div class=\"ols-table-wrap\">\n<table class=\"ols-table\">\n<thead>\n<tr><th>Substance and change<\/th><th>Thermodynamically<\/th><th>Kinetically<\/th><th>Reason<\/th><\/tr>\n<\/thead>\n<tbody>\n<tr><td><strong>Water at room temperature, splitting into hydrogen and oxygen<\/strong><\/td><td>stable<\/td><td>not relevant: the change is not feasible<\/td><td>\u0394G for 2H\u2082O(l) \u2192 2H\u2082(g) + O\u2082(g) is +474 kJ mol\u207b\u00b9<\/td><\/tr>\n<tr><td><strong>A mixture of hydrogen and oxygen, forming water<\/strong><\/td><td><strong>unstable<\/strong><\/td><td><strong>stable<\/strong><\/td><td>feasible, but with an activation energy so high that the rate at 298 K is effectively zero<\/td><\/tr>\n<tr><td><strong>Diamond, turning into graphite<\/strong><\/td><td>unstable<\/td><td>stable<\/td><td>turning one giant covalent lattice into another needs a huge number of strong C\u2013C bonds to break<\/td><\/tr>\n<tr><td><strong>Petrol, paper, wood and the glucose in the body, in air<\/strong><\/td><td>unstable<\/td><td>stable<\/td><td>the same reason: a high activation energy<\/td><\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<ul class=\"ols-list\">\n<li>For water, no catalyst or waiting time will change the positive \u0394G. Only a supply of energy, such as electricity, can split it.<\/li>\n<li>The word <strong>stable<\/strong> on its own is not enough in an answer: say which kind, and with respect to what change.<\/li>\n<\/ul>\n<h3>The link with AS kinetics<\/h3>\n<p>The link with the AS kinetics idea is direct. A reaction profile shows both quantities:<\/p>\n<ul class=\"ols-list\">\n<li>The height of the hump above the reactants is E\u2090, which controls the rate.<\/li>\n<li>The gap between reactants and products is the enthalpy change, which (with the entropy change) controls feasibility.<\/li>\n<li>A very exothermic reaction can have a very high E\u2090, and a small activation energy can sit on a reaction that is not feasible at all.<\/li>\n<li>Raising the temperature or adding a catalyst changes how many collisions cross the barrier; it does not change whether the products are lower than the reactants.<\/li>\n<\/ul>\n<div class=\"ols-figure-card ols-zoom-pop\">\n<div class=\"ols-figure-image\">\n<a class=\"ols-image-fullscreen-link\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/09\/entropy-t12-05-stability.jpg\" target=\"_blank\" rel=\"noopener\" aria-label=\"Open image fullscreen\">\n<img decoding=\"async\" src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/09\/entropy-t12-05-stability.jpg\" alt=\"Reaction profile for a thermodynamically feasible but kinetically sta\" data-fullscreen-src=\"https:\/\/www.onlinelearningsystem.net\/xyz\/wp-content\/uploads\/2026\/09\/entropy-t12-05-stability.jpg\">\n<\/a>\n<\/div>\n<div class=\"ols-figure-caption\"><p>A reaction profile for hydrogen and oxygen at room temperature, feasible (large negative \u0394G) but kinetically stable (very large activation energy), beside definitions of the two kinds of stability.<\/p><\/div>\n<\/div>\n<div class=\"ols-key-box\">\n<p><strong>Exam wording:<\/strong> &#8220;The reaction is thermodynamically feasible because \u0394G is negative, but the activation energy is very high, so at room temperature the rate is negligible: the mixture is kinetically stable.&#8221;<\/p>\n<\/div>\n<\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Check: Which Kind of Stability?<\/h2>\n<p>Classify substances and mixtures not used on this page as thermodynamically stable or kinetically stable with respect to a given change, and justify the choice.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-1108\" class=\"h5p-iframe\" data-content-id=\"1108\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Entropy and Energetics Drag: Thermodynamically or Kinetically Stable?\"><\/iframe><\/div><\/div>\n<\/section>\n<article class=\"ols-note-card\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">3<\/div>\n<h2>The Limits of the Prediction<\/h2>\n<\/div>\n<p>The specification asks you to understand why a reaction with a negative \u0394G may not occur in practice, and the activation energy is the main answer. There are three more limits to keep in mind.<\/p>\n<h3>1. The values are for standard conditions<\/h3>\n<ul class=\"ols-list\">\n<li>The values are for <strong>standard conditions<\/strong>: 298 K, 100 kPa and concentrations of 1 mol dm\u207b\u00b3.<\/li>\n<li>A \u0394G calculated from standard data describes the reaction under those conditions. At other concentrations or pressures the actual Gibbs energy change is different.<\/li>\n<li>A reaction that is just not feasible under standard conditions may become feasible if the products are removed as they form.<\/li>\n<li>One that is feasible may stop if the product concentration builds up.<\/li>\n<li>Feasible means the equilibrium lies towards the products, not that the reaction goes to completion in every case.<\/li>\n<\/ul>\n<h3>2. \u0394H and \u0394S drift with temperature<\/h3>\n<ul class=\"ols-list\">\n<li>\u0394S_total is calculated assuming \u0394H and \u0394S keep their standard values at the temperature used.<\/li>\n<li>That is a good approximation over a few hundred kelvin, but the values do drift.<\/li>\n<li>So a calculated crossing temperature is an estimate rather than an exact figure.<\/li>\n<\/ul>\n<h3>3. Nothing is said about the mechanism<\/h3>\n<ul class=\"ols-list\">\n<li>\u0394S_total says nothing about the <strong>mechanism<\/strong>.<\/li>\n<li>A feasible reaction may need a catalyst to provide a route with a lower activation energy, as the synthesis of ammonia does (feasible at 298 K, but immeasurably slow without iron).<\/li>\n<li>A feasible overall change may go through an intermediate step that is itself not feasible. The direct route is then blocked and the change does not happen in that way at all.<\/li>\n<li>The thermodynamic prediction is a statement about the start and the end, and only that.<\/li>\n<\/ul>\n<div class=\"ols-key-box\">\n<p><strong>Exam focus:<\/strong> Reasons a reaction with a favourable \u0394S_total may not occur: a high activation energy (the reaction is kinetically stable); non-standard conditions; the absence of a catalyst or a suitable mechanism. The most common expected answer is the first.<\/p>\n<\/div>\n<\/article>\n<article class=\"ols-note-card\">\n<div class=\"ols-note-title\">\n<div class=\"ols-note-icon\">4<\/div>\n<h2>Common Exam Points<\/h2>\n<\/div>\n<h3>Say<\/h3>\n<ul class=\"ols-list\">\n<li>&#8220;The reaction is feasible, but the activation energy is high, so the rate is very low at this temperature.&#8221;<\/li>\n<li>&#8220;Thermodynamically unstable but kinetically stable.&#8221;<\/li>\n<li>&#8220;\u0394S_total predicts feasibility, not rate.&#8221;<\/li>\n<\/ul>\n<h3>Do not say<\/h3>\n<ul class=\"ols-list\">\n<li>&#8220;The reaction does not happen because \u0394G is negative&#8221; (a negative \u0394G makes it feasible).<\/li>\n<li>&#8220;The substance is stable&#8221; (stable with respect to what, and in which sense?).<\/li>\n<li>&#8220;A catalyst makes the reaction feasible&#8221; (a catalyst changes the rate; it cannot change the sign of \u0394S_total).<\/li>\n<\/ul>\n<h3>Watch for<\/h3>\n<ul class=\"ols-list\">\n<li>Questions that give a negative \u0394G and ask why nothing is observed: activation energy every time.<\/li>\n<li>Questions that give a positive \u0394G and ask why a catalyst does not help: the reaction is not feasible, so no route will make it go.<\/li>\n<li>Questions on standard conditions: point out that concentrations other than 1 mol dm\u207b\u00b3 change the actual \u0394G.<\/li>\n<\/ul>\n<\/article>\n<section class=\"ols-h5p-card ols-h5p-inline\">\n<span class=\"ols-h5p-kicker\">Check your understanding<\/span>\n<h2>Check: Why a Feasible Reaction Does Not Happen<\/h2>\n<p>Explain why feasible reactions not used on this page are not observed, using activation energy and the other limits of the prediction.<\/p>\n<div class=\"ols-h5p-frame\"><div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-1109\" class=\"h5p-iframe\" data-content-id=\"1109\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Entropy and Energetics Explain: Why a Feasible Reaction Does Not Happen\"><\/iframe><\/div><\/div>\n<\/section>\n<section class=\"ols-faq-card\">\n<h2>FAQs<\/h2>\n<p>Use these quick answers to check the difference between thermodynamic and kinetic stability.<\/p>\n\n<div class=\"ols-faq-list\">\n<div class=\"ols-faq-item\">\n<h3>Why is diamond still around if graphite is more stable?<\/h3>\n<p>Diamond is thermodynamically unstable with respect to graphite, because the change has a negative \u0394G and a positive \u0394Stotal, but it is kinetically stable. Converting it needs a huge number of strong C\u2013C bonds to be broken and remade, so the activation energy is enormous and the rate at room temperature is effectively zero.<\/p>\n<\/div>\n\n<div class=\"ols-faq-item\">\n<h3>What is the difference between thermodynamically stable and kinetically stable?<\/h3>\n<p>Thermodynamically stable means the reaction is not feasible: \u0394Stotal is negative, so no amount of waiting will make it go. Kinetically stable means the reaction is feasible but so slow, because of a high activation energy, that nothing happens on any useful timescale. Petrol in air is kinetically stable; it needs a spark.<\/p>\n<\/div>\n\n<div class=\"ols-faq-item\">\n<h3>If a reaction is feasible, why does adding a catalyst not change how far it goes?<\/h3>\n<p>A catalyst lowers the activation energy and so speeds the reaction up, but it does not alter \u0394H or \u0394S of the reaction, so it cannot make an infeasible reaction feasible or change the equilibrium position. It only lets a feasible reaction reach equilibrium faster.<\/p>\n<\/div>\n\n<div class=\"ols-faq-item\">\n<h3>How can I tell from a question whether a reaction is limited by thermodynamics or by kinetics?<\/h3>\n<p>Work out the sign of \u0394Stotal first. If the reaction is not feasible, that is the whole explanation. If it is feasible but does not happen, the answer is a high activation energy: the reactants are kinetically stable, and heating or a catalyst may set the reaction off.<\/p>\n<\/div>\n\n<div class=\"ols-faq-item\">\n<h3>Does a feasible reaction always give a high yield?<\/h3>\n<p>No. Feasibility only says the reaction can go; a \u0394Stotal close to zero means an equilibrium mixture with substantial amounts of both reactants and products. A large negative \u0394G, or a large positive \u0394Stotal, suggests the equilibrium lies far to the right, but even then the rate can be too slow to obtain any product.<\/p>\n<\/div>\n<\/div>\n<\/section>\n<section class=\"ols-related-card\">\n<h2>Related Topic 12 Entropy and Energetics Pages<\/h2>\n<p>Use these pages to connect the ideas across Topic 12 Entropy and Energetics and the rest of the course.<\/p>\n<div class=\"ols-related-grid\">\n<a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-12-entropy-and-energetics\/entropy-and-the-direction-of-change\/\">Entropy and the Direction of Change<\/a>\n<a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-12-entropy-and-energetics\/calculating-entropy-changes\/\">Calculating Entropy Changes<\/a>\n<a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-12-entropy-and-energetics\/feasibility-gibbs-energy-and-temperature\/\">Feasibility and Temperature<\/a>\n<a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-12-entropy-and-energetics\/lattice-energy-and-born-haber-cycles\/\">Lattice Energy and Born\u2013Haber Cycles<\/a>\n<a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-12-entropy-and-energetics\/lattice-energy-trends-and-covalent-character\/\">Lattice Energy Trends and Covalent Character<\/a>\n<a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-12-entropy-and-energetics\/enthalpy-of-solution-and-hydration\/\">Enthalpy of Solution and Hydration<\/a>\n<a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-12-entropy-and-energetics\/predicting-solubility\/\">Predicting Solubility<\/a>\n<a class=\"ols-related-item\" href=\"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-12-entropy-and-energetics\/\">Topic 12 Entropy and Energetics Overview<\/a>\n<\/div>\n<\/section>\n<section class=\"ols-attribution-card\">\n        <p><strong>Copyright notice:<\/strong> This OLS revision content, including the explanations, layout, diagrams, tables and embedded learning structure, is authored for Online Learning System by Dr. Mohammed Al-Fatah. It may not be copied, reproduced, redistributed or adapted without written permission.<\/p>\n      <\/section>\n    <\/main>\n  \n\n<script type=\"application\/ld+json\">\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@graph\": [\n    {\n      \"@type\": \"WebPage\",\n      \"@id\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-12-entropy-and-energetics\/thermodynamic-and-kinetic-stability\/#webpage\",\n      \"url\": \"https:\/\/www.onlinelearningsystem.net\/xyz\/revision-notes\/a-level-chemistry\/edexcel-international\/topic-12-entropy-and-energetics\/thermodynamic-and-kinetic-stability\/\",\n      \"name\": \"Thermodynamic and Kinetic Stability | Topic 12 Entropy and Energetics | Online Learning System\",\n      \"description\": \"Edexcel International A Level Chemistry revision notes on thermodynamic and kinetic stability: feasible but slow reactions, activation energy and the limits of \u0394G and \u0394Stotal 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