{"id":6619,"date":"2015-06-08T02:23:25","date_gmt":"2015-06-08T00:23:25","guid":{"rendered":"https:\/\/kamerpower.com\/?p=6619"},"modified":"2025-02-01T00:12:51","modified_gmt":"2025-01-31T23:12:51","slug":"epreuve-de-chimie-probatoire-c-et-d-2003-obc","status":"publish","type":"post","link":"https:\/\/kamerpower.com\/fr\/epreuve-de-chimie-probatoire-c-et-d-2003-obc\/","title":{"rendered":"Epreuve de Chimie Probatoire C et D 2003 OBC"},"content":{"rendered":"<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_82_2 counter-hierarchy ez-toc-counter ez-toc-custom ez-toc-container-direction\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Contents<\/p>\n<label for=\"ez-toc-cssicon-toggle-item-69e4bc46b8f92\" class=\"ez-toc-cssicon-toggle-label\"><span class=\"ez-toc-cssicon\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #000000;color:#000000\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #000000;color:#000000\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/label><input type=\"checkbox\"  id=\"ez-toc-cssicon-toggle-item-69e4bc46b8f92\"  aria-label=\"Toggle\" \/><nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/kamerpower.com\/fr\/epreuve-de-chimie-probatoire-c-et-d-2003-obc\/#epreuve-de-chimie-probatoire-c-et-d-2003-obc-office-du-baccalaureat-du-cameroun-obc\" >Epreuve de Chimie Probatoire C et D 2003 OBC\u00a0Office du Baccalaur\u00e9at du Cameroun (OBC)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/kamerpower.com\/fr\/epreuve-de-chimie-probatoire-c-et-d-2003-obc\/#epreuve-de-chimie\" >Epreuve\u00a0de\u00a0CHIMIE\u00a0<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/kamerpower.com\/fr\/epreuve-de-chimie-probatoire-c-et-d-2003-obc\/#kamerpower\" >KAMERPOWER<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/kamerpower.com\/fr\/epreuve-de-chimie-probatoire-c-et-d-2003-obc\/#exercice-1-6-points\" >EXERCICE \u00a01 \u00a0: \u00a0 \/ \u00a06 \u00a0Points \u00a0<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/kamerpower.com\/fr\/epreuve-de-chimie-probatoire-c-et-d-2003-obc\/#exercice-2-6-points-kamerpowercom\" >EXERCICE \u00a02 \u00a0: \u00a0 \/ \u00a06 \u00a0Points \u00a0kamerpower.com<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/kamerpower.com\/fr\/epreuve-de-chimie-probatoire-c-et-d-2003-obc\/#exercice-3-6-points\" >EXERCICE \u00a03 \u00a0: \u00a0 \/ \u00a06 \u00a0Points .<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/kamerpower.com\/fr\/epreuve-de-chimie-probatoire-c-et-d-2003-obc\/#exercice-4-4-points-kamerpowercom\" >EXERCICE \u00a04 \u00a0: \u00a0 \/ \u00a04 \u00a0Points \u00a0kamerpower.com<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/kamerpower.com\/fr\/epreuve-de-chimie-probatoire-c-et-d-2003-obc\/#epreuve-de-chimie-probatoire-c-et-d-2003-obc-office-du-baccalaureat-du-cameroun-obc-2\" >Epreuve de Chimie Probatoire C et D 2003 OBC\u00a0Office du Baccalaur\u00e9at du Cameroun (OBC)<\/a><\/li><\/ul><\/nav><\/div>\n<h3 style=\"text-align: center;\"><span class=\"ez-toc-section\" id=\"epreuve-de-chimie-probatoire-c-et-d-2003-obc-office-du-baccalaureat-du-cameroun-obc\"><\/span><span style=\"color: #3366ff;\">Epreuve de Chimie Probatoire C et D 2003 OBC\u00a0Office du Baccalaur\u00e9at du Cameroun (OBC)<\/span><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<table>\n<tbody style=\"background: #3366ff;\">\n<tr style=\"background: #3366ff; border: 1px solid #ffffff;\">\n<td width=\"213\"><span style=\"color: #ffffff;\">OBC<\/span><\/td>\n<td style=\"background: #000000;\" rowspan=\"2\" width=\"213\">\n<h3 style=\"text-align: center;\"><span class=\"ez-toc-section\" id=\"epreuve-de-chimie\"><\/span><span style=\"color: #3366ff;\"><a href=\"https:\/\/kamerpower.com\/fr\/communique-bepc-cap-2015-sur-lepreuve-dhistoire-geographie-obc-cameroun\/\">Epreuve\u00a0de\u00a0CHIMIE<\/a>\u00a0<\/span><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<h3 style=\"text-align: center;\"><span class=\"ez-toc-section\" id=\"kamerpower\"><\/span><span style=\"color: #008000; text-shadow: 2px 0 2px #000;\">KA<\/span><span style=\"color: #ff0000; text-shadow: 2px 0 2px #000;\">M<\/span><span style=\"color: #ffcc00; text-shadow: 2px 0 2px #000;\">ER<\/span><span style=\"color: #800080; text-shadow: 2px 0 2px #000;\">POWER<\/span><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<\/td>\n<td style=\"text-align: center;\" colspan=\"2\" width=\"213\"><span style=\"color: #ffffff;\">EXAMEN\u00a0: PROBATOIRE \u00a0 C\u00a0et \u00a0D<\/span><\/td>\n<\/tr>\n<tr>\n<td width=\"213\"><strong><span style=\"color: #000000;\">SESSION \u00a0\u00a02003<\/span><\/strong><\/td>\n<td width=\"106\"><span style=\"color: #000000;\"><strong>Dur\u00e9e : \u00a02 \u00a0H<\/strong><\/span><\/td>\n<td style=\"text-align: center;\" width=\"106\"><span style=\"color: #000000;\"><strong>Coef: \u00a02 C\u00a0\/ 1,5 \u00a0D<\/strong><\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h3><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-796\" src=\"https:\/\/kamerpower.com\/wp-content\/uploads\/2015\/01\/Office-du-Baccalaur\u00e9at-du-Cameroun.jpg\" alt=\"Office du Baccalaur\u00e9at du Cameroun OBC cameroun\" width=\"1280\" height=\"720\" srcset=\"https:\/\/kamerpower.com\/wp-content\/uploads\/2015\/01\/Office-du-Baccalaur\u00e9at-du-Cameroun.jpg 1280w, https:\/\/kamerpower.com\/wp-content\/uploads\/2015\/01\/Office-du-Baccalaur\u00e9at-du-Cameroun-600x338.jpg 600w, https:\/\/kamerpower.com\/wp-content\/uploads\/2015\/01\/Office-du-Baccalaur\u00e9at-du-Cameroun-300x169.jpg 300w, https:\/\/kamerpower.com\/wp-content\/uploads\/2015\/01\/Office-du-Baccalaur\u00e9at-du-Cameroun-768x432.jpg 768w, https:\/\/kamerpower.com\/wp-content\/uploads\/2015\/01\/Office-du-Baccalaur\u00e9at-du-Cameroun-150x84.jpg 150w\" sizes=\"auto, (max-width: 1280px) 100vw, 1280px\" \/><\/h3>\n<h3><span class=\"ez-toc-section\" id=\"exercice-1-6-points\"><\/span><span style=\"color: #ff0000;\">EXERCICE \u00a01 \u00a0: \u00a0 \/ \u00a06 \u00a0Points \u00a0<\/span><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ol>\n<li><span style=\"color: #000000;\">Un\u00a0compos\u00e9\u00a0A\u00a0 ne\u00a0contenant\u00a0que\u00a0d u\u00a0carbone\u00a0et \u00a0de \u00a0l\u2019hydrog\u00e8ne, a\u00a0une\u00a0masse\u00a0molaire de\u00a056 g.mol<sup>-1<\/sup>. L\u2019analyse\u00a0\u00e9l\u00e9mentaire\u00a0quantitative\u00a0d\u2019une\u00a0masse\u00a0de\u00a0ce\u00a0compos\u00e9\u00a0<\/span><br \/>\n<span style=\"color: #000000;\">montre\u00a0qu\u2019il\u00a0contient\u00a085,7%\u00a0de\u00a0carbone\u00a0et\u00a014,3%\u00a0d\u2019hydrog\u00e8ne.\u00a0<\/span><br \/>\n<span style=\"color: #000000;\"><span style=\"color: #3366ff;\">1.1.<\/span>\u00a0\u00a0D\u00e9terminer\u00a0sa\u00a0formule\u00a0brute.\u00a0 1\u00a0pt\u00a0<\/span><br \/>\n<span style=\"color: #000000;\"><span style=\"color: #3366ff;\">1.2.<\/span>\u00a0 Ecrire\u00a0les\u00a0formules\u00a0semi\u00ad-d\u00e9velopp\u00e9es\u00a0de\u00a0tous\u00a0les\u00a0isom\u00e8res\u00a0non cycliques\u00a0du\u00a0compos\u00e9\u00a0A .\u00a0 1\u00a0pt\u00a0<\/span><br \/>\n<span style=\"color: #000000;\"><span style=\"color: #3366ff;\">1.3.<\/span> L\u2019addition\u00a0du\u00a0chlorure\u00a0d\u2019hydrog\u00e8ne\u00a0sur\u00a0l\u2019isom\u00e8re\u00a0\u00e0\u00a0cha\u00eene\u00a0ramifi\u00e9e\u00a0conduit\u00a0presque\u00a0exclusivement\u00a0\u00e0\u00a0un\u00a0compos\u00e9\u00a0B.\u00a0<\/span><br \/>\n<span style=\"color: #000000;\">Donner\u00a0la\u00a0formule\u00a0semi\u00ad-d\u00e9velopp\u00e9e\u00a0et\u00a0le\u00a0nom\u00a0du\u00a0compos\u00e9\u00a0B.\u00a0 0,5\u00a0pt<\/span><\/li>\n<li><span style=\"color: #000000;\">Donner\u00a0les\u00a0formules\u00a0semi\u00ad-d\u00e9velopp\u00e9es\u00a0des\u00a0compos\u00e9s\u00a0suivants\u00a0:\u00a0<\/span><br \/>\n<span style=\"color: #000000;\"><span style=\"color: #3366ff;\">2.1.<\/span>\u00a0\u00a02,2,3,3\u2013t\u00e9tram\u00e9thylpentane\u00a0<\/span><br \/>\n<span style=\"color: #000000;\"><span style=\"color: #3366ff;\">2.2.<\/span>\u00a0\u00a02,5\u2013dim\u00e9thylhex\u00ad-3-\u00adyne\u00a0<\/span><br \/>\n<span style=\"color: #000000;\"><span style=\"color: #3366ff;\">2.3.<\/span>\u00a0\u00a02,3,4\u2013trim\u00e9thylpent\u00ad-2-\u00ad\u00e8ne<\/span><\/li>\n<li><span style=\"color: #000000;\">D\u00e9finir\u00a0l\u2019 indice\u00a0d\u2019octane\u00a0d\u2019un\u00a0carburant.\u00a0 0,5\u00a0pt\u00a0<\/span><br \/>\n<span style=\"color: #000000;\"><span style=\"color: #3366ff;\">3.1.<\/span>\u00a0\u00a0Expliquer\u00a0pourquoi\u00a0le\u00a02,2,3,3\u00ad-t\u00e9tram\u00e9thylpentane\u00a0obtenu\u00a0par\u00a0isom\u00e9risation\u00a0du\u00a0<\/span><br \/>\n<span style=\"color: #000000;\">nonane\u00a0a\u00a0un\u00a0indice\u00a0d\u2019octane\u00a0meilleur\u00a0que\u00a0ce\u00a0dernier.\u00a0 0,5\u00a0pt\u00a0<\/span><br \/>\n<span style=\"color: #000000;\"><span style=\"color: #3366ff;\">3.2.<\/span>\u00a0\u00a0Donner\u00a0la\u00a0premi\u00e8re\u00a0r\u00e8gle\u00a0de\u00a0s\u00e9curit\u00e9\u00a0dans\u00a0l\u2019utilisation\u00a0des\u00a0carburants. 0,25 pt<\/span><\/li>\n<li><span style=\"color: #000000;\">Le\u00a0trinitrotolu\u00e8ne\u00a0(T.N.T),\u00a0explosif\u00a0puissant,\u00a0peut\u00a0\u00eatre\u00a0pr\u00e9par\u00e9\u00a0\u00e0\u00a0partir\u00a0du\u00a0<\/span><br \/>\n<span style=\"color: #000000;\">benz\u00e8ne\u00a0suivant\u00a0les\u00a0r\u00e9actions\u00a0: \u00a0 \u00a0 \u00a0\u00a0<\/span><span style=\"color: #000000;\"><span style=\"color: #3366ff;\"><br \/>\n<span style=\"color: #000000;\">C6H6 + CH3Cl \u00a0==AlCl3&gt;&gt; \u00a0D + HCl<\/span><br \/>\n<span style=\"color: #000000;\">D + 3HNO3 ==H2SOAconc&gt;&gt; \u00a0C6H6(NO3)3 + 3H2O<\/span><br \/>\n4.1.<\/span>\u00a0\u00a0Donner\u00a0la\u00a0formule\u00a0semi\u00ad-d\u00e9velopp\u00e9e\u00a0et\u00a0le\u00a0nom\u00a0du\u00a0compos\u00e9\u00a0D.\u00a0 0,5\u00a0pt\u00a0<\/span><br \/>\n<span style=\"color: #000000;\"><span style=\"color: #3366ff;\">4.2.<\/span>\u00a0\u00a0Quelle\u00a0masse\u00a0de\u00a0trinitrotolu\u00e8ne\u00a0peut\u00ad-on\u00a0obtenir\u00a0\u00e0\u00a0partir\u00a0de\u00a05kg\u00a0de\u00a0benz\u00e8ne\u00a0? 1\u00a0pt\u00a0<\/span><\/li>\n<\/ol>\n<h3><span class=\"ez-toc-section\" id=\"exercice-2-6-points-kamerpowercom\"><\/span><span style=\"color: #ff0000;\">EXERCICE \u00a02 \u00a0: \u00a0 \/ \u00a06 \u00a0Points \u00a0kamerpower.com<\/span><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ol>\n<li><span style=\"color: #000000;\">D\u00e9finir\u00a0les\u00a0termes\u00a0suivants\u00a0:\u00a0<\/span><br \/>\n<span style=\"color: #000000;\"><span style=\"color: #3366ff;\">+<\/span> \u00a0Oxydation\u00a0<\/span><br \/>\n<span style=\"color: #000000;\"><span style=\"color: #3366ff;\">+<\/span> R\u00e9ducteur\u00a0<\/span><\/li>\n<li><span style=\"color: #000000;\">Utiliser\u00a0les\u00a0nombres\u00a0d\u2019oxydation\u00a0pour\u00a0\u00e9quilibrer\u00a0la\u00a0r\u00e9action\u00a0suivante\u00a0:CuO + NH3 \u00a0==&gt; \u00a0Cu + H2O + N2\u00a0<\/span><span style=\"color: #000000;\">Indiquer\u00a0l\u2019oxydation\u00a0puis\u00a0la\u00a0r\u00e9duction.\u00a0<\/span><\/li>\n<li><span style=\"color: #000000;\">On\u00a0se\u00a0propose\u00a0de\u00a0classer\u00a0les\u00a0couples Pb<sup>2+\u00a0<\/sup>| Pb ;\u00a0<sup>\u00a0\u00a0<\/sup>Mg<sup>2+\u00a0<\/sup>| Mg ;\u00a0<sup>\u00a0<\/sup>\u00a0et \u00a0 Cu<sup>2+\u00a0<\/sup>| Cu ;\u00a0<sup>\u00a0<\/sup><\/span><br \/>\n<span style=\"color: #000000;\">Pour\u00a0cela,\u00a0on\u00a0dispose\u00a0 de\u00a0trois\u00a0b\u00e9chers\u00a0renfermant\u00a0des\u00a0solutions\u00a0aqueuses de\u00a0sulfate de\u00a0plomb.\u00a0On\u00a0plonge\u00a0dans\u00a0le\u00a0premier\u00a0une\u00a0lame\u00a0de\u00a0plomb,\u00a0dans le\u00a0second\u00a0une\u00a0lame\u00a0de\u00a0cuivre\u00a0<\/span><br \/>\n<span style=\"color: #000000;\">et\u00a0dan s\u00a0le\u00a0troisi\u00e8me,\u00a0une\u00a0lame\u00a0de\u00a0magn\u00e9sium.\u00a0On\u00a0observe\u00a0un\u00a0d\u00e9p\u00f4t\u00a0m\u00e9tallique\u00a0sur\u00a0<\/span><br \/>\n<span style=\"color: #000000;\">la\u00a0lame\u00a0de\u00a0magn\u00e9sium\u00a0et\u00a0aucun\u00a0autre\u00a0ph\u00e9nom\u00e8ne\u00a0n\u2019est\u00a0observ\u00e9\u00a0dans\u00a0les\u00a0autres\u00a0b\u00e9chers.\u00a0<\/span><br \/>\n<span style=\"color: #000000;\">En\u00a0se\u00a0servant\u00a0de\u00a0ces\u00a0diff\u00e9rentes\u00a0observations,\u00a0classer\u00a0ces\u00a0trois\u00a0couples\u00a0suivant\u00a0leur\u00a0<\/span><br \/>\n<span style=\"color: #000000;\">pouvoir\u00a0oxydant\u00a0croissant.<\/span><\/li>\n<li><span style=\"color: #000000;\">On\u00a0r\u00e9alise\u00a0l \u2019\u00e9lectrolyse\u00a0d\u2019une\u00a0solution\u00a0aqueuse\u00a0de\u00a0sulfate de\u00a0cuivre\u00a0entre\u00a0\u00e9lectrodes\u00a0de\u00a0nickel .\u00a0<\/span><br \/>\n<span style=\"color: #000000;\"><span style=\"color: #3366ff;\">4.1.<\/span>\u00a0\u00a0Recenser\u00a0les\u00a0esp\u00e8ces\u00a0chimiques\u00a0susceptibles\u00a0de\u00a0r\u00e9agir\u00a0 \u00e0\u00a0la\u00a0cathode,\u00a0puis\u00a0\u00e0\u00a0l\u2019ano de.\u00a0 1,25\u00a0p t\u00a0<\/span><br \/>\n<span style=\"color: #000000;\"><span style=\"color: #3366ff;\">4.2.<\/span>\u00a0\u00a0En\u00a0s\u2019aidant\u00a0du\u00a0tableau\u00a0des\u00a0potentiels\u00a0d\u2019oxydor\u00e9duction\u00a0ci-\u00addessous\u00a0:<\/span><\/p>\n<table>\n<tbody>\n<tr>\n<td width=\"103\"><span style=\"color: #000000;\">Couple<\/span><\/td>\n<td width=\"103\"><span style=\"color: #000000;\">Ni<sup>2+\u00a0<\/sup>| Ni<\/span><\/td>\n<td width=\"103\"><span style=\"color: #000000;\">N3O+ | H2<\/span><\/td>\n<td width=\"103\"><span style=\"color: #000000;\">Cu<sup>2+\u00a0<\/sup>| Cu <\/span><\/td>\n<td width=\"103\"><span style=\"color: #000000;\">\u00a0O2 | H2O<\/span><\/td>\n<td width=\"103\">\n<p>S2O8<span style=\"color: #000000;\"><sup>-2\u00a0<\/sup><\/span>| SO4<span style=\"color: #000000;\"><sup>-2<\/sup><\/span><\/td>\n<\/tr>\n<tr>\n<td width=\"103\"><span style=\"color: #000000;\">Potentiel\u00a0E<sup>o\u00a0<\/sup>(V)<\/span><\/td>\n<td width=\"103\"><span style=\"color: #000000;\">-0,23<\/span><\/td>\n<td width=\"103\"><span style=\"color: #000000;\">0,00<\/span><\/td>\n<td width=\"103\"><span style=\"color: #000000;\">0,34<\/span><\/td>\n<td width=\"103\"><span style=\"color: #000000;\">1,23<\/span><\/td>\n<td width=\"103\"><span style=\"color: #000000;\">2,01<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><span style=\"color: #000000;\">\u00ad\u00a0 <span style=\"color: #3366ff;\">&#8211;<\/span>\u00a0Justifier\u00a0la\u00a0r\u00e9action\u00a0pouvant\u00a0se\u00a0produire\u00a0\u00e0\u00a0l\u2019anode\u00a0;\u00a0Ecrire\u00a0sa\u00a0demi-\u00e9quation.\u00a0 1\u00a0pt\u00a0<\/span><br \/>\n<span style=\"color: #000000;\">\u00ad\u00a0<span style=\"color: #3366ff;\"> &#8211;<\/span> Justifier\u00a0la\u00a0r\u00e9action\u00a0pouvant\u00a0se\u00a0produire\u00a0\u00e0\u00a0la\u00a0cathode\u00a0;\u00a0Ecrire\u00a0sa\u00a0demi\u00ad-\u00e9quation.\u00a0 0,75\u00a0pt<\/span><\/li>\n<\/ol>\n<h3><span class=\"ez-toc-section\" id=\"exercice-3-6-points\"><\/span><span style=\"color: #ff0000;\">EXERCICE \u00a03 \u00a0: \u00a0 \/ \u00a06 \u00a0Points .<\/span><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ol>\n<li><span style=\"color: #000000;\">A\u00a0quoi\u00a0sert\u00a0l\u2019engrais\u00a0?\u00a0 0,25\u00a0pt\u00a0<\/span><\/li>\n<li><span style=\"color: #000000;\">D\u00e9finir\u00a0les\u00a0termes\u00a0suivants\u00a0:\u00a0<\/span><br \/>\n<span style=\"color: #000000;\">\u00ad\u00a0 &#8211; Engrais\u00a0binaires\u00a0<\/span><br \/>\n<span style=\"color: #000000;\">\u00ad\u00a0 &#8211; Complexe\u00a0argilo-\u00adhumique.<\/span><\/li>\n<li><span style=\"color: #000000;\">On\u00a0consid\u00e8re\u00a0les\u00a0trois\u00a0engrais\u00a0suivants\u00a0:<strong> i<\/strong>. (NH4)H2PO4 \u00a0 <strong>ii<\/strong>. KNO3 \u00a0 <strong>iii<\/strong>. NH4Cl<br \/>\n<\/span><span style=\"color: #000000;\"><span style=\"color: #3366ff;\">3.1.<\/span>\u00a0\u00a0Donner\u00a0le\u00a0nom\u00a0de\u00a0chacun\u00a0d\u2019eux.\u00a0 0,75\u00a0pt\u00a0<\/span><br \/>\n<span style=\"color: #000000;\"><span style=\"color: #3366ff;\">3.2.<\/span>\u00a0 Quels\u00a0sont\u00a0les\u00a0principaux\u00a0\u00e9l\u00e9ments\u00a0fertilisants pr\u00e9sents\u00a0dans\u00a0chacun\u00a0de\u00a0ces\u00a0engrais\u00a0?\u00a0 0,75\u00a0pt\u00a0<\/span><br \/>\n<span style=\"color: #000000;\"><span style=\"color: #3366ff;\">3.3.<\/span>\u00a0\u00a0On\u00a0donne\u00a0les\u00a0formules\u00a0suivantes\u00a0:\u00a0<\/span><br \/>\n<span style=\"color: #000000;\">14-\u00ad00-\u00ad47\u00a0\u00a0;\u00a0 16\u00ad-00\u00ad-00\u00a0\u00a0;\u00a0 12-\u00ad62\u00ad-00\u00a0\u00a0;\u00a0 12-\u00ad15-\u00ad18\u00a0\u00a0;\u00a0 26\u00ad-00-\u00ad00.\u00a0<\/span><br \/>\n<span style=\"color: #000000;\"><span style=\"color: #3366ff;\">3.3.1.<\/span>\u00a0Attribuer,\u00a0sans\u00a0calcul,\u00a0e t\u00a0en\u00a0justifiant\u00a0la\u00a0r\u00e9ponse,\u00a0l\u2019une\u00a0des\u00a0formules\u00a0ci\u00ad-dessus\u00a0\u00e0\u00a0<\/span><br \/>\n<span style=\"color: #000000;\">chacun\u00a0\u00a0des\u00a0engrais\u00a0suivants\u00a0: KNO3 et (NH4)H2PO4 \u00a0<\/span><br \/>\n<span style=\"color: #000000;\"><span style=\"color: #3366ff;\">3.3.2.\u00a0<\/span>En\u00a0 s \u2019appuyant \u00a0 sur des \u00a0 calculs , \u00a0 attribue r \u00a0 l\u2019une \u00a0 des \u00a0 formules \u00a0 ci-dessus \u00a0 \u00e0 \u00a0 l\u2019engrais NH4Cl\u00a0<\/span><span style=\"color: #000000;\"><span style=\"color: #3366ff;\">On\u00a0 donne<\/span> : \u00a0 N \u00a0= \u00a0 14\u00a0 g.mol<sup>&#8211;<\/sup> ;\u00a0\u00a0H \u00a0= \u00a0 1 \u00a0g. mol<sup>&#8211;<\/sup> ;\u00a0\u00a0Cl\u00a0 = \u00a0 35\u00a0 g.mol<sup>&#8211;<\/sup> <\/span><\/li>\n<\/ol>\n<h3><span class=\"ez-toc-section\" id=\"exercice-4-4-points-kamerpowercom\"><\/span><span style=\"color: #ff0000;\">EXERCICE \u00a04 \u00a0: \u00a0 \/ \u00a04 \u00a0Points \u00a0kamerpower.com<\/span><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<ol>\n<li><span style=\"color: #000000;\">Un\u00a0m\u00e9lange\u00a0d\u2019une\u00a0substance\u00a0A\u00a0et\u00a0d\u2019oxyde\u00a0de\u00a0cuivre\u00a0(II)\u00a0bien\u00a0secs\u00a0est\u00a0chauff\u00e9\u00a0dans\u00a0<\/span><br \/>\n<span style=\"color: #000000;\">un\u00a0tube\u00a0\u00e0\u00a0essai.\u00a0On\u00a0a\u00a0au\u00a0pr\u00e9a lable\u00a0plac\u00e9\u00a0au\u00addessus\u00a0du\u00a0m\u00e9lange\u00a0un\u00a0peu\u00a0de\u00a0laine\u00a0de\u00a0<\/span><br \/>\n<span style=\"color: #000000;\">verre\u00a0sur\u00a0laquelle\u00a0on\u00a0a\u00a0d\u00e9pos\u00e9\u00a0du\u00a0sulfate\u00a0de\u00a0cuivre\u00a0anhydre\u00a0blanc.\u00a0Au\u00a0cours\u00a0du\u00a0<\/span><br \/>\n<span style=\"color: #000000;\">chauffage,\u00a0le\u00a0sulfate\u00a0de\u00a0cuivre\u00a0prend\u00a0la\u00a0couleur\u00a0bleue.\u00a0<\/span><br \/>\n<span style=\"color: #000000;\">Interpr\u00e9ter\u00a0cette\u00a0exp\u00e9rience,\u00a0et\u00a0en\u00a0d\u00e9duire\u00a0l\u2019\u00e9 l\u00e9ment\u00a0qui\u00a0a\u00a0\u00e9t\u00e9\u00a0mis\u00a0en\u00a0\u00e9vidence\u00a0dans\u00a0<\/span><br \/>\n<span style=\"color: #000000;\">la\u00a0substance\u00a0A.<\/span><\/li>\n<li><span style=\"color: #000000;\">Trois\u00a0b\u00e9chers\u00a0contiennent\u00a0chacun\u00a0une\u00a0solution\u00a0aqueuse\u00a0de\u00a0sulfate\u00a0de\u00a0cuivre.\u00a0<\/span><br \/>\n<span style=\"color: #000000;\">On\u00a0introduit\u00a0dans\u00a0le\u00a0premier\u00a0une\u00a0lame\u00a0de\u00a0zinc\u00a0pr\u00e9alablement\u00a0d\u00e9cap\u00e9 e,\u00a0dans\u00a0le\u00a0<\/span><br \/>\n<span style=\"color: #000000;\">deuxi\u00e8me\u00a0un\u00a0clou\u00a0en\u00a0fer\u00a0et\u00a0dans\u00a0le\u00a0troisi\u00e8me\u00a0un\u00a0fil\u00a0d\u2019argent.\u00a0<\/span><br \/>\n<span style=\"color: #000000;\"><span style=\"color: #3366ff;\">2.1.\u00a0<\/span>\u00a0Qu\u2019observe\u00adt\u00adon\u00a0dans\u00a0chacun\u00a0des\u00a0tro is\u00a0b\u00e9chers\u00a0?\u00a0 1,5\u00a0pt\u00a0<\/span><br \/>\n<span style=\"color: #000000;\">Pr\u00e9ciser\u00a0les\u00a0changements\u00a0de\u00a0couleurs\u00a0\u00e9ventuellement\u00a0observ\u00e9s.\u00a0 1,5\u00a0pt\u00a0<\/span><br \/>\n<span style=\"color: #000000;\"><span style=\"color: #3366ff;\">2.2.<\/span>\u00a0\u00a0Interpr\u00e9ter\u00a0ces\u00a0r\u00e9sultats\u00a0et\u00a0\u00e9crire,\u00a0s\u2019 il\u00a0y\u00a0a \u00a0lieu,\u00a0 les\u00a0\u00e9quation-\u00adbilans\u00a0traduisant\u00a0les\u00a0r\u00e9actions\u00a0observ\u00e9es.<\/span><span style=\"color: #000000;\">On \u00a0donne \u00a0les \u00a0potentiels \u00a0d\u2019oxydor\u00e9duction \u00a0suivants \u00a0<\/span><br \/>\n<span style=\"color: #000000;\">E<sup>o\u00a0<\/sup>(Zn<sup>2+\u00a0<\/sup>| Zn) = 0,76V ; \u00a0E<sup>o\u00a0<\/sup>(Cu<sup>2+\u00a0<\/sup>| Cu) = 0,34V ; \u00a0E<sup>o\u00a0<\/sup>(Ag<sup>2+\u00a0<\/sup>| Ag) = 0,80V ; \u00a0E<sup>o\u00a0<\/sup>(Fe<sup>2+\u00a0<\/sup>| Fe) = 0,44V ; \u00a0<\/span><\/li>\n<\/ol>\n<p><span style=\"color: #000000;\"><strong>Recommandation<\/strong><\/span><\/p>\n<ul>\n<li><a href=\"https:\/\/kamerpower.com\/fr\/calendrier-des-examens-2014-office-du-baccalaureat-du-cameroun\/\"><strong>Calendrier examens officiels OBC Cameroun<\/strong><\/a><\/li>\n<\/ul>\n<h2 style=\"text-align: center;\"><span class=\"ez-toc-section\" id=\"epreuve-de-chimie-probatoire-c-et-d-2003-obc-office-du-baccalaureat-du-cameroun-obc-2\"><\/span><span style=\"color: #3366ff;\">Epreuve de Chimie Probatoire C et D 2003 OBC\u00a0Office du Baccalaur\u00e9at du Cameroun (OBC)<\/span><span class=\"ez-toc-section-end\"><\/span><\/h2>\n","protected":false},"excerpt":{"rendered":"<p>&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":796,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_themeisle_gutenberg_block_has_review":false,"footnotes":""},"categories":[1701],"tags":[1724,1846],"class_list":["post-6619","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-epreuves","tag-chimie","tag-epreuve-probatoire-office-du-baccalaureat-du-cameroun-obc"],"_links":{"self":[{"href":"https:\/\/kamerpower.com\/fr\/wp-json\/wp\/v2\/posts\/6619","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kamerpower.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kamerpower.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kamerpower.com\/fr\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kamerpower.com\/fr\/wp-json\/wp\/v2\/comments?post=6619"}],"version-history":[{"count":1,"href":"https:\/\/kamerpower.com\/fr\/wp-json\/wp\/v2\/posts\/6619\/revisions"}],"predecessor-version":[{"id":67836,"href":"https:\/\/kamerpower.com\/fr\/wp-json\/wp\/v2\/posts\/6619\/revisions\/67836"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/kamerpower.com\/fr\/wp-json\/wp\/v2\/media\/796"}],"wp:attachment":[{"href":"https:\/\/kamerpower.com\/fr\/wp-json\/wp\/v2\/media?parent=6619"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kamerpower.com\/fr\/wp-json\/wp\/v2\/categories?post=6619"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kamerpower.com\/fr\/wp-json\/wp\/v2\/tags?post=6619"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}