{"id":92,"date":"2024-10-24T20:50:49","date_gmt":"2024-10-25T00:50:49","guid":{"rendered":"https:\/\/sites.temple.edu\/chemdemo\/?p=92"},"modified":"2024-10-25T16:22:01","modified_gmt":"2024-10-25T20:22:01","slug":"hoffmann-electrolysis","status":"publish","type":"post","link":"https:\/\/sites.temple.edu\/chemdemo\/2024\/10\/24\/hoffmann-electrolysis\/","title":{"rendered":"Hoffmann Electrolysis"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">Overview<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>A little bit of soap helps visualize the gases produced.<\/li>\n\n\n\n<li><strong>Important:<\/strong> Do not forget to add the electrolyte!<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Reactions<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Cathode Reaction (Reduction)<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>At the negatively charged cathode, a reduction reaction occurs:<br>Cathode\u00a0(reduction): 2 H<sup>+<\/sup> (aq) + 2 e<sup>\u2212 <\/sup>\u2192 H<sub>2<\/sub> \u200b(g)<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Anode Reaction (Oxidation)<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>At the positively charged anode, an oxidation reaction occurs:<br>Anode\u00a0(oxidation): 2 H2\u200bO (l) \u2192 O2 \u200b(g) + 4 H<sup>+<\/sup> (aq) + 4e<sup>\u2212<\/sup><\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Alternate Half Reactions<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The same half reactions can also be balanced with base:<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Cathode Reaction (with Base)<\/h2>\n\n\n\n<p>Cathode\u00a0(reduction): 2 H2\u200bO (l) + 2e<sup>\u2212<\/sup> \u2192 H<sub>2<\/sub> \u200b(g) + 2 OH<sup>\u2212<\/sup> (aq)<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Anode Reaction (with Base)<\/h2>\n\n\n\n<p>Anode\u00a0(oxidation): 4OH<sup>\u2212<\/sup> (aq) \u2192 O2\u200b (g) + 2 H2\u200bO (l) + 4e<sup>\u2212<\/sup><\/p>\n\n\n\n<p>Overall Reaction<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Combining either pair of half reactions yields the same overall decomposition of water into oxygen and hydrogen:<br><\/li>\n\n\n\n<li>Overall\u00a0reaction: 2 H2\u200bO (l) \u2192 2 H2\u200b (g) + O2\u200b (g)<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">Key Observations<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The number of hydrogen molecules produced is twice that of oxygen molecules.<\/li>\n\n\n\n<li>Assuming equal temperature and pressure, the produced hydrogen gas occupies twice the volume of the produced oxygen gas.<\/li>\n\n\n\n<li>The number of electrons pushed through the water is twice the number of generated hydrogen molecules and four times the number of generated oxygen molecules.<\/li>\n<\/ul>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Overview Reactions Cathode Reaction (Reduction) Anode Reaction (Oxidation) Alternate Half Reactions Cathode Reaction (with Base) Cathode\u00a0(reduction): 2 H2\u200bO (l) + 2e\u2212 \u2192 H2 \u200b(g) +&#8230;<\/p>\n<div class=\"more-link-wrapper\"><a class=\"more-link\" href=\"https:\/\/sites.temple.edu\/chemdemo\/2024\/10\/24\/hoffmann-electrolysis\/\">Continue Reading<span class=\"screen-reader-text\">Hoffmann Electrolysis<\/span><\/a><\/div>\n","protected":false},"author":36673,"featured_media":0,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[],"class_list":["post-92","post","type-post","status-publish","format-standard","hentry","category-demonstrations","entry"],"_links":{"self":[{"href":"https:\/\/sites.temple.edu\/chemdemo\/wp-json\/wp\/v2\/posts\/92","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sites.temple.edu\/chemdemo\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/sites.temple.edu\/chemdemo\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/sites.temple.edu\/chemdemo\/wp-json\/wp\/v2\/users\/36673"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.temple.edu\/chemdemo\/wp-json\/wp\/v2\/comments?post=92"}],"version-history":[{"count":1,"href":"https:\/\/sites.temple.edu\/chemdemo\/wp-json\/wp\/v2\/posts\/92\/revisions"}],"predecessor-version":[{"id":93,"href":"https:\/\/sites.temple.edu\/chemdemo\/wp-json\/wp\/v2\/posts\/92\/revisions\/93"}],"wp:attachment":[{"href":"https:\/\/sites.temple.edu\/chemdemo\/wp-json\/wp\/v2\/media?parent=92"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/sites.temple.edu\/chemdemo\/wp-json\/wp\/v2\/categories?post=92"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/sites.temple.edu\/chemdemo\/wp-json\/wp\/v2\/tags?post=92"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}