{"id":5740,"date":"2026-10-14T22:13:50","date_gmt":"2026-10-14T19:13:50","guid":{"rendered":"https:\/\/wpcalc.com\/fr\/chimie\/calculateur-constante-equilibre-electrochimique\/"},"modified":"2026-10-14T22:13:50","modified_gmt":"2026-10-14T19:13:50","slug":"calculateur-constante-equilibre-electrochimique","status":"publish","type":"post","link":"https:\/\/wpcalc.com\/fr\/chimie\/calculateur-constante-equilibre-electrochimique\/","title":{"rendered":"Calculateur de constante d'\u00e9quilibre \u00e9lectrochimique"},"content":{"rendered":"<section class=\"not-prose calculator-box\" aria-labelledby=\"calculator-title\"><div class=\"flex items-baseline sm:items-center justify-between gap-2 sm:gap-3\"><div class=\"flex flex-col sm:flex-row sm:items-center gap-2\"><span class=\"icon icon-calculator text-primary-700! text-base! dark:text-primary-300!\" aria-hidden=\"true\"><\/span><h2 id=\"calculator-title\" class=\"text-lg font-display font-bold\">D\u00e9terminer K \u00e0 partir du potentiel standard de la pile<\/h2><\/div><div class=\"calcdash-favorite group\">\n  <button type=\"button\" class=\"favorite\" id=\"favorite\" data-favorite-id=\"5740\" data-favorite-title=\"Constante d&#039;\u00e9quilibre \u00e9lectrochimique\" data-favorite-url=\"https:\/\/wpcalc.com\/fr\/chimie\/calculateur-constante-equilibre-electrochimique\/\" data-favorite-excerpt=\"Saisissez le potentiel standard de pile E\u00b0pile, le nombre d&#039;\u00e9lectrons \u00e9chang\u00e9s n et la temp\u00e9rature pour d\u00e9terminer la constante d&#039;\u00e9quilibre K d&#039;une r\u00e9action d&#039;oxydor\u00e9duction \u00e0 partir de la relation \u0394G\u00b0 = \u2212nFE\u00b0 = \u2212RT ln K.\" aria-label=\"Ajouter aux favoris\" data-favorite-icon=\"icon icon-chemistry-1\">\n    <span class=\"icon icon-shape-star-empty\" aria-hidden=\"true\"><\/span>\n  <\/button>\n  <div class=\"calcdash-favorite__tip\" aria-hidden=\"true\">\n   <span class=\"favorite-tooltip\" id=\"favorite-tooltip\"><\/span>\n  <\/div>\n  <span class=\"sr-only\" role=\"status\" id=\"favorite-status\"><\/span>\n<\/div><\/div><form action=\"https:\/\/wpcalc.com\/fr\/chimie\/calculateur-constante-equilibre-electrochimique\/\" method=\"POST\" class=\"calculator\" id=\"calculator-5740\" data-post=\"5740\"><fieldset class=\"fieldset-input is-2\"><legend class=\"sr-only\">Champs de saisie<\/legend><div class=\"field has-term\" id=\"input-1\"><label for=\"field-1\">Potentiel standard de la pile (E\u00b0cell)<\/label><div class=\"term\">E\u00b0cell<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><div class=\"field-group\"><input type=\"number\" name=\"potentiel_standard_de_la_pile_ecell\" id=\"field-1\" aria-describedby=\"calc-info-1\" placeholder=\"e.g. 1.10\" step=\"any\" value=\"1.1\"\/><div class=\"grid grid-cols-1\"><select id=\"field-2\" name=\"unit\" aria-label=\"Unit\u00e9\"><option value=\"V\" selected>V<\/option><option value=\"mV\">mV<\/option><\/select><svg class=\"pointer-events-none col-start-1 row-start-1 mr-2 size-5 self-center justify-self-end text-gray-500 sm:size-4\" viewBox=\"0 0 16 16\" fill=\"currentColor\" aria-hidden=\"true\" data-slot=\"icon\">\n              <path fill-rule=\"evenodd\" d=\"M4.22 6.22a.75.75 0 0 1 1.06 0L8 8.94l2.72-2.72a.75.75 0 1 1 1.06 1.06l-3.25 3.25a.75.75 0 0 1-1.06 0L4.22 7.28a.75.75 0 0 1 0-1.06Z\" clip-rule=\"evenodd\" \/>\n            <\/svg><\/div><\/div><small id=\"calc-info-1\">Diff\u00e9rence des potentiels standard de r\u00e9duction : E\u00b0cell = E\u00b0cathode \u2212 E\u00b0anode. Les valeurs n\u00e9gatives sont admises et donnent simplement K &lt; 1.<\/small><\/div><div class=\"field has-term\" id=\"input-2\"><label for=\"field-3\">Nombre d&#039;\u00e9lectrons \u00e9chang\u00e9s (n)<\/label><div class=\"term\">n<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"text\" name=\"nombre_dlectrons_changs_n\" id=\"field-3\" aria-describedby=\"calc-info-3\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" placeholder=\"e.g. 2\" min=\"0\" value=\"2\"\/><small id=\"calc-info-3\">Nombre d&#039;\u00e9lectrons \u00e9chang\u00e9s dans la r\u00e9action d&#039;oxydor\u00e9duction \u00e9quilibr\u00e9e (par ex. 2 pour Zn + Cu\u00b2\u207a \u2192 Zn\u00b2\u207a + Cu).<\/small><\/div><div class=\"field has-term\" id=\"input-3\"><label for=\"field-4\">Temp\u00e9rature (T)<\/label><div class=\"term\">T<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><div class=\"field-group\"><input type=\"number\" name=\"temprature_t\" id=\"field-4\" aria-describedby=\"calc-info-4\" placeholder=\"e.g. 25\" step=\"any\" value=\"25\"\/><div class=\"grid grid-cols-1\"><select id=\"field-5\" name=\"unit\" aria-label=\"Unit\u00e9\"><option value=\"C\" selected>\u00b0C<\/option><option value=\"K\">K<\/option><option value=\"F\">\u00b0F<\/option><\/select><svg class=\"pointer-events-none col-start-1 row-start-1 mr-2 size-5 self-center justify-self-end text-gray-500 sm:size-4\" viewBox=\"0 0 16 16\" fill=\"currentColor\" aria-hidden=\"true\" data-slot=\"icon\">\n              <path fill-rule=\"evenodd\" d=\"M4.22 6.22a.75.75 0 0 1 1.06 0L8 8.94l2.72-2.72a.75.75 0 1 1 1.06 1.06l-3.25 3.25a.75.75 0 0 1-1.06 0L4.22 7.28a.75.75 0 0 1 0-1.06Z\" clip-rule=\"evenodd\" \/>\n            <\/svg><\/div><\/div><small id=\"calc-info-4\">Temp\u00e9rature de la pile. 25 \u00b0C (298,15 K) est la r\u00e9f\u00e9rence standard des valeurs E\u00b0 tabul\u00e9es.<\/small><\/div><\/fieldset><div class=\"buttons\"><button type=\"submit\" data-text=\"Recalculer\" id=\"calculate-button\" data-post=\"5740\">Calculer<\/button><button type=\"reset\">R\u00e9initialiser<\/button><\/div><div class=\"field is-checkbox hidden!\" id=\"field-auto-calc\"><input type=\"checkbox\" id=\"auto-calc\"><label for=\"auto-calc\">Calculer automatiquement<\/label><small>Si activ\u00e9, le r\u00e9sultat se met \u00e0 jour automatiquement d\u00e8s que vous modifiez une valeur.<\/small><\/div><div class=\"fieldset-result is-hidden\" aria-labelledby=\"result-title\" aria-live=\"polite\" role=\"region\"> <h3 class=\"result-title bg-gradient-to-r from-primary-50 to-gray-50 dark:from-primary-900 dark:to-gray-800\" id=\"result-title\"><span class=\"icon icon-s-pulse\" aria-hidden=\"true\"><\/span> R\u00e9sultats de la constante d&#039;\u00e9quilibre<\/h3><div class=\"result-box\"><div class=\"field-result is-column\" id=\"output-1\"><span class=\"field-title\"><span>Constante d&#039;\u00e9quilibre (K)<\/span><span class=\"result-term\">K<\/span><\/span><span class=\"field-value\" id=\"result-1\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copier le r\u00e9sultat\" aria-label=\"Copier le r\u00e9sultat\"><span class=\"copy-icon icon icon-document-copy\" aria-hidden=\"true\"><\/span><\/button><\/div><div class=\"field-result\" id=\"output-2\"><span class=\"field-title\"><span>log\u2081\u2080 K<\/span><span class=\"result-term\">log K<\/span><\/span><span class=\"field-value\" id=\"result-2\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copier le r\u00e9sultat\" aria-label=\"Copier le r\u00e9sultat\"><span class=\"copy-icon icon icon-document-copy\" aria-hidden=\"true\"><\/span><\/button><\/div><div class=\"field-result is-column\" id=\"output-3\"><span class=\"field-title\"><span>D\u00e9tails du calcul<\/span><\/span><span class=\"field-value\" id=\"result-3\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copier le r\u00e9sultat\" aria-label=\"Copier le r\u00e9sultat\"><span class=\"copy-icon icon icon-document-copy\" aria-hidden=\"true\"><\/span><\/button><\/div><div class=\"field-result is-column\" id=\"output-4\"><span class=\"field-title\"><span>\u00c0 propos de ce calcul<\/span><\/span><span class=\"field-value\" id=\"result-4\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copier le r\u00e9sultat\" aria-label=\"Copier le r\u00e9sultat\"><span class=\"copy-icon icon icon-document-copy\" aria-hidden=\"true\"><\/span><\/button><\/div><\/div><div class=\"result-actions\"><button type=\"button\" class=\"copy-link\"><svg viewBox=\"0 0 20 20\" fill=\"currentColor\" aria-hidden=\"true\"><path d=\"M12.232 4.232a2.5 2.5 0 0 1 3.536 3.536l-1.225 1.224a.75.75 0 0 0 1.061 1.06l1.224-1.224a4 4 0 0 0-5.656-5.656l-3 3a4 4 0 0 0 .225 5.865.75.75 0 0 0 .977-1.138 2.5 2.5 0 0 1-.142-3.667l3-3Z\"\/><path d=\"M11.603 7.963a.75.75 0 0 0-.977 1.138 2.5 2.5 0 0 1 .142 3.667l-3 3a2.5 2.5 0 0 1-3.536-3.536l1.225-1.224a.75.75 0 0 0-1.061-1.06l-1.224 1.224a4 4 0 1 0 5.656 5.656l3-3a4 4 0 0 0-.225-5.865Z\"\/><\/svg><span class=\"copy-link__text\">Copier le lien vers ce calcul<\/span><\/button><span class=\"sr-only\" role=\"status\" id=\"copy-link-status\"><\/span><\/div><\/div><a href=\"#respond\" class=\"hidden transition-opacity duration-300 opacity-0 w-50 text-sm justify-center items-center gap-2 px-4 py-2 rounded bg-gray-200 text-gray-700 hover:bg-gray-300\" id=\"leave-comment\"><span class=\"icon icon-comments\" aria-hidden=\"true\"><\/span>Laisser un commentaire<\/a><\/form><\/section><section id=\"calc-reactions\" class=\"not-prose hidden my-12 bg-gradient-to-r from-primary-50 to-gray-50 border border-indigo-100 rounded-xl px-6 py-4 shadow-sm\" data-post=\"5740\" aria-live=\"polite\" aria-labelledby=\"calc-reactions-title\"><p id=\"calc-reactions-title\" class=\"text-sm text-gray-500 text-center mb-2\">Que pensez-vous de ce r\u00e9sultat\u00a0?<\/p><div role=\"group\" aria-labelledby=\"calc-reactions-title\" class=\"grid grid-cols-3 sm:flex sm:flex-row sm:justify-around gap-4 sm:items-center sm:flex-wrap\"><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"like\"><span class=\"reaction-count\" data-reaction-count=\"like\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\ude00 <\/span><span class=\"reaction-description font-medium\">J\u2019aime <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"helpful\"><span class=\"reaction-count\" data-reaction-count=\"helpful\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\udca1 <\/span><span class=\"reaction-description font-medium\">Utile <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"confused\"><span class=\"reaction-count\" data-reaction-count=\"confused\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\ude15 <\/span><span class=\"reaction-description font-medium\">Confus <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"disappointed\"><span class=\"reaction-count\" data-reaction-count=\"disappointed\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\ude1e <\/span><span class=\"reaction-description font-medium\">D\u00e9\u00e7u <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"inaccurate\"><span class=\"reaction-count\" data-reaction-count=\"inaccurate\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\u274c <\/span><span class=\"reaction-description font-medium\">Inexact <\/span><\/button><\/div><div id=\"reaction-message\" class=\"hidden mt-8 rounded-md border border-primary-100 bg-white\/50 backdrop-blur-sm px-4 py-2 text-sm text-center shadow-sm\"><\/div><\/section><div class=\"calcdash-ad not-prose calcdash-ad--calc_result calcdash-ad--in-article\"><ins class=\"adsbygoogle\" style=\"display:block\" data-ad-client=\"ca-pub-1721569815777345\" data-ad-slot=\"6317458308\" data-ad-layout=\"in-article\" data-ad-format=\"fluid\"><\/ins><script>(adsbygoogle = window.adsbygoogle || []).push({});<\/script><\/div>\n<style id=\"wpcoderpro-inline-1\">.formula-box {\r\n\tborder-bottom: none !important;\r\n}<\/style><section class=\"formula-box\" aria-labelledby=\"formula-title\">\r\n\t<div id=\"formula-title\" class=\"not-prose font-display mb-4\"><span class=\"icon icon-formula\" aria-hidden=\"true\"><\/span><h2>Formule de la constante d'\u00e9quilibre \u00e9lectrochimique<\/h2><\/div>\r\n\t<figure class=\"not-prose formula\">\r\n\t\t<figcaption class=\"formula-title\">Formule<\/figcaption>\r\n\t\t<div class=\"text-base text-gray-800\" id=\"formula\">\n\\[ \\ln K = \\frac{nFE^\\circ_{cell}}{RT} \\quad \\Leftrightarrow \\quad \\log_{10} K = \\frac{nFE^\\circ_{cell}}{2.303\\,RT} \\]\n<\/div>\r\n\t<\/figure>\r\n\t<\/p>\n<p><strong>O\u00f9\u00a0:<\/strong><\/p>\n<ul>\n<li>\\(K\\) \u2014 constante d'\u00e9quilibre de la r\u00e9action d'oxydor\u00e9duction (sans dimension)<\/li>\n<li>\\(n\\) \u2014 nombre d'\u00e9lectrons \u00e9chang\u00e9s dans l'\u00e9quation \u00e9quilibr\u00e9e<\/li>\n<li>\\(F\\) \u2014 constante de Faraday, 96 485,33212 C\/mol<\/li>\n<li>\\(E^\\circ_{cell}\\) \u2014 potentiel standard de la pile, en volts (V)<\/li>\n<li>\\(R\\) \u2014 constante des gaz parfaits, 8,314462618 J\/(mol\u00b7K)<\/li>\n<li>\\(T\\) \u2014 temp\u00e9rature absolue, en kelvins (K)<\/li>\n<\/ul>\n<p>Cette formule combine deux expressions de la variation d'enthalpie libre standard, \\(\\Delta G^\\circ = -nFE^\\circ_{cell}\\) et \\(\\Delta G^\\circ = -RT\\ln K\\). En les \u00e9galisant, on voit que la tension de la pile mesure directement la position de l'\u00e9quilibre\u00a0: plus elle est \u00e9lev\u00e9e, plus celui-ci est d\u00e9plac\u00e9 vers les produits.<\/p>\n<p>\r\n<\/section>\n<style id=\"wpcoderpro-inline-2\">.calculation-box {\r\n\tborder-bottom: none !important;\r\n}<\/style><section id=\"calculation\" class=\"calculation-box\" aria-labelledby=\"calculation-title\">\r\n\t<div id=\"calculation-title\" class=\"not-prose font-display\"><span class=\"icon icon-unordered-list\" aria-hidden=\"true\"><\/span><h2>Constante d'\u00e9quilibre \u00e9lectrochimique \u2013 Exemple de calcul<\/h2><\/div>\r\n\r\n<\/p>\n<p><strong>Exemple\u00a0:<\/strong> la pile de Daniell, Zn(s) + Cu\u00b2\u207a(aq) \u2192 Zn\u00b2\u207a(aq) + Cu(s), pr\u00e9sente un E\u00b0pile de 1,10 V et \u00e9change n = 2 \u00e9lectrons \u00e0 25 \u00b0C (298,15 K).<\/p>\n<p>\\[ \\log_{10} K = \\frac{nFE^\\circ_{cell}}{2.303\\,RT} = \\frac{2 \\times 96485.33 \\times 1.10}{2.303 \\times 8.3145 \\times 298.15} \\approx 37.19 \\]<\/p>\n<p><strong>R\u00e9sultat\u00a0:<\/strong> \\(K = 10^{37.19} \\approx 1.55 \\times 10^{37}\\). L'\u00e9quilibre est massivement d\u00e9plac\u00e9 du c\u00f4t\u00e9 des produits\u00a0: la r\u00e9action est pour ainsi dire totale.<\/p>\n<p>\n\r\n<\/section>\n<h2>Comment utiliser le calculateur<\/h2>\n<ol>\n<li>Saisissez le <strong>potentiel standard de la pile (E\u00b0pile)<\/strong>, soit E\u00b0cathode \u2212 E\u00b0anode, et choisissez l'unit\u00e9 V ou mV. Les valeurs n\u00e9gatives sont accept\u00e9es et donnent simplement un K &lt; 1.<\/li>\n<li>Saisissez le <strong>nombre d'\u00e9lectrons \u00e9chang\u00e9s (n)<\/strong>, c'est-\u00e0-dire le nombre d'\u00e9lectrons qui se simplifient quand on combine les deux demi-\u00e9quations (par ex. 2 pour Zn + Cu\u00b2\u207a \u2192 Zn\u00b2\u207a + Cu).<\/li>\n<li>Saisissez la <strong>temp\u00e9rature (T)<\/strong> et s\u00e9lectionnez \u00b0C, K ou \u00b0F. Les potentiels standard tabul\u00e9s se r\u00e9f\u00e8rent \u00e0 25 \u00b0C (298,15 K).<\/li>\n<li>Lisez les r\u00e9sultats\u00a0: la constante d'\u00e9quilibre K (en notation scientifique), la valeur de log\u2081\u2080K et le d\u00e9tail du calcul montrant, \u00e9tape par \u00e9tape, la substitution des constantes.<\/li>\n<\/ol>\n<h2>Qu'est-ce que la constante d'\u00e9quilibre \u00e9lectrochimique\u00a0?<\/h2>\n<p>Chaque r\u00e9action d'oxydor\u00e9duction poss\u00e8de une constante d'\u00e9quilibre qui indique jusqu'o\u00f9 elle progresse avant d'atteindre l'\u00e9quilibre. Pour la pile de Daniell, K \u2248 10\u00b3\u2077 signifie que le zinc m\u00e9tallique r\u00e9duit les ions cuivre pratiquement totalement. Mesurer chimiquement de telles constantes colossales est vou\u00e9 \u00e0 l'\u00e9chec \u2014 les concentrations de l'esp\u00e8ce qui \u00ab\u00a0perd\u00a0\u00bb deviennent trop faibles pour \u00eatre mesur\u00e9es \u2014, mais le potentiel de pile les r\u00e9v\u00e8le indirectement et avec une grande sensibilit\u00e9.<\/p>\n<p>Le lien se fait par l'enthalpie libre. Une pile fournit un travail \u00e9lectrique \u00e9gal \u00e0 \\(nFE^\\circ_{cell}\\) par mole de r\u00e9action, et ce m\u00eame \\(\\Delta G^\\circ\\) fixe aussi K par la relation \\(\\Delta G^\\circ = -RT\\ln K\\). Comme \\(F\/RT\\) est tr\u00e8s grand (environ 38,9 V\u207b\u00b9 \u00e0 25 \u00b0C par unit\u00e9 de ln), chaque volt de potentiel de pile correspond \u00e0 plusieurs dizaines de puissances de dix dans K. Une variation de seulement 59,2 mV de E\u00b0pile d\u00e9cale log\u2081\u2080K d'une unit\u00e9 enti\u00e8re par \u00e9lectron \u00e9chang\u00e9.<\/p>\n<p>L'interpr\u00e9tation du r\u00e9sultat est simple\u00a0: un E\u00b0pile positif signifie \\(\\Delta G^\\circ &lt; 0\\) et K &gt; 1 (produits favoris\u00e9s dans les conditions standard)\u00a0; un E\u00b0pile nul donne K = 1\u00a0; un E\u00b0pile n\u00e9gatif donne K &lt; 1 (r\u00e9actifs favoris\u00e9s). Quand |log\u2081\u2080K| d\u00e9passe une trentaine, la r\u00e9action est si unilat\u00e9rale qu'elle est exp\u00e9rimentalement indiscernable d'une r\u00e9action totale \u2014 le calculateur affiche alors K sous forme de puissance de dix plut\u00f4t qu'en nombre d\u00e9cimal.<\/p>\n<p>Pour obtenir E\u00b0pile lui-m\u00eame, cherchez les deux potentiels standard de r\u00e9duction et effectuez la soustraction, ou utilisez notre <a href=\"https:\/\/wpcalc.com\/en\/chemistry\/standard-cell-potential-calculator\/\">calculateur de potentiel standard de pile<\/a>. La m\u00eame logique fond\u00e9e sur les activit\u00e9s qui sous-tend ce K r\u00e9git aussi le <a href=\"https:\/\/wpcalc.com\/en\/chemistry\/solubility-product-ksp-calculator\/\">produit de solubilit\u00e9 Ksp<\/a>, et la comptabilit\u00e9 d'enthalpie libre fait \u00e9cho \u00e0 la <a href=\"https:\/\/wpcalc.com\/fr\/chimie\/calculateur-loi-hess\/\">loi de Hess<\/a>.<\/p>\n<h2>Hypoth\u00e8ses, limites et conseils pratiques<\/h2>\n<ul>\n<li><strong>Conditions standard\u00a0:<\/strong> la formule suppose que toutes les esp\u00e8ces sont \u00e0 l'activit\u00e9 unit\u00e9 (1 mol\/L pour les solut\u00e9s, 1 bar pour les gaz). Hors conditions tr\u00e8s dilu\u00e9es, les concentrations r\u00e9elles diff\u00e8rent des activit\u00e9s \u2014 consultez le <a href=\"https:\/\/wpcalc.com\/fr\/chimie\/coefficient-activite-debye-huckel\/\">calculateur de coefficient d'activit\u00e9 Debye\u2013H\u00fcckel<\/a> pour les corrections en solution ionique.<\/li>\n<li><strong>\u00c9quation \u00e9quilibr\u00e9e indispensable\u00a0:<\/strong> n doit provenir de l'\u00e9quation compl\u00e8tement \u00e9quilibr\u00e9e. Multipliez les demi-\u00e9quations pour \u00e9liminer les \u00e9lectrons avant de les compter\u00a0; une valeur erron\u00e9e de n d\u00e9cale log K proportionnellement.<\/li>\n<li><strong>Coh\u00e9rence des temp\u00e9ratures\u00a0:<\/strong> les valeurs E\u00b0 tabul\u00e9es sont mesur\u00e9es \u00e0 25 \u00b0C. Si vous saisissez une autre temp\u00e9rature, le calculateur applique correctement la relation formelle, mais le v\u00e9ritable E\u00b0pile varie lui aussi l\u00e9g\u00e8rement avec T\u00a0: consid\u00e9rez donc les r\u00e9sultats obtenus en dehors de 25 \u00b0C comme des approximations.<\/li>\n<li><strong>Chiffres significatifs\u00a0:<\/strong> les potentiels standard sont g\u00e9n\u00e9ralement donn\u00e9s avec 2 \u00e0 3 d\u00e9cimales\u00a0; log K d\u00e9passe donc rarement 2 \u00e0 3 chiffres significatifs, et, pour K elle-m\u00eame, seul le premier chiffre de la mantisse est significatif.<\/li>\n<li><strong>K est sans dimension\u00a0:<\/strong> c'est la constante thermodynamique fond\u00e9e sur les activit\u00e9s, et non le quotient des concentrations molaires. En solution dilu\u00e9e, les deux co\u00efncident presque.<\/li>\n<li><strong>n non entier\u00a0:<\/strong> le calculateur accepte un n fractionnaire (par ex. par mole d'une entit\u00e9 formule choisie), mais K se rapporte alors \u00e0 la r\u00e9action \u00e9crite de cette fa\u00e7on pr\u00e9cise \u2014 modifier l'\u00e9chelle de l'\u00e9quation change n et K ensemble.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Saisissez le potentiel standard de pile E\u00b0pile, le nombre d'\u00e9lectrons \u00e9chang\u00e9s n et la temp\u00e9rature pour d\u00e9terminer la constante d'\u00e9quilibre K d'une r\u00e9action d'oxydor\u00e9duction \u00e0 partir de la relation \u0394G\u00b0 = \u2212nFE\u00b0 = \u2212RT ln K.<\/p>\n","protected":false},"author":3168,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[17],"tags":[34],"class_list":["post-5740","post","type-post","status-publish","format-standard","hentry","category-chimie","tag-reactions"],"acf":[],"_links":{"self":[{"href":"https:\/\/wpcalc.com\/fr\/wp-json\/wp\/v2\/posts\/5740","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wpcalc.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wpcalc.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wpcalc.com\/fr\/wp-json\/wp\/v2\/users\/3168"}],"replies":[{"embeddable":true,"href":"https:\/\/wpcalc.com\/fr\/wp-json\/wp\/v2\/comments?post=5740"}],"version-history":[{"count":1,"href":"https:\/\/wpcalc.com\/fr\/wp-json\/wp\/v2\/posts\/5740\/revisions"}],"predecessor-version":[{"id":5918,"href":"https:\/\/wpcalc.com\/fr\/wp-json\/wp\/v2\/posts\/5740\/revisions\/5918"}],"wp:attachment":[{"href":"https:\/\/wpcalc.com\/fr\/wp-json\/wp\/v2\/media?parent=5740"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpcalc.com\/fr\/wp-json\/wp\/v2\/categories?post=5740"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpcalc.com\/fr\/wp-json\/wp\/v2\/tags?post=5740"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}