{"id":216070,"date":"2025-05-18T12:53:54","date_gmt":"2025-05-18T12:53:54","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=216070"},"modified":"2025-05-18T12:53:57","modified_gmt":"2025-05-18T12:53:57","slug":"designing-a-galvanic-cell-from-a-single-displacement-redox-reaction","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/05\/18\/designing-a-galvanic-cell-from-a-single-displacement-redox-reaction\/","title":{"rendered":"Designing a galvanic cell from a single-displacement redox reaction"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">Designing a galvanic cell from a single-displacement redox reaction<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Suppose the galvanic cell sketched below is powered by the following reaction:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Mg(s) + ZnCl2(aq) ? MgCl2(aq) + Zn(s)<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Write a balanced equation for the half-reaction that happens at the cathode of this cell.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Zn2+(aq) + 2e- ? Zn(s)<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-1-color\">The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Correct Answer:<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Half-reaction at the cathode:<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">$$<br>\\text{Zn}^{2+}(aq) + 2e^- \\rightarrow \\text{Zn}(s)<br>$$<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Detailed Explanation (300+ words):<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A <strong>galvanic cell<\/strong> (also called a <strong>voltaic cell<\/strong>) is a type of electrochemical cell that uses a <strong>spontaneous redox reaction<\/strong> to generate electrical energy. The cell is composed of two half-cells: one for oxidation and one for reduction. The two electrodes are connected by a wire (for electron flow) and a salt bridge (for ion movement), allowing a redox reaction to occur in separate locations while producing an electric current.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In the given reaction:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">$$<br>\\text{Mg}(s) + \\text{ZnCl}_2(aq) \\rightarrow \\text{MgCl}_2(aq) + \\text{Zn}(s)<br>$$<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is a <strong>single-displacement redox reaction<\/strong> where <strong>magnesium metal (Mg)<\/strong> displaces <strong>zinc ions (Zn\u00b2\u207a)<\/strong> from solution, forming <strong>magnesium ions (Mg\u00b2\u207a)<\/strong> and solid <strong>zinc metal (Zn)<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">To understand what&#8217;s happening at the cathode, we must break the full reaction into <strong>half-reactions<\/strong>, separating the oxidation and the reduction processes.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Step 1: Identify Oxidation and Reduction<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Oxidation (loss of electrons)<\/strong> happens when magnesium goes from solid to ion: $$<br>\\text{Mg}(s) \\rightarrow \\text{Mg}^{2+}(aq) + 2e^-<br>$$<\/li>\n\n\n\n<li><strong>Reduction (gain of electrons)<\/strong> happens when zinc ions gain electrons to form solid zinc: $$<br>\\text{Zn}^{2+}(aq) + 2e^- \\rightarrow \\text{Zn}(s)<br>$$<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Step 2: Determine the Cathode Reaction<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">In a galvanic cell:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Oxidation<\/strong> occurs at the <strong>anode<\/strong><\/li>\n\n\n\n<li><strong>Reduction<\/strong> occurs at the <strong>cathode<\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Since <strong>zinc ions are being reduced<\/strong> to solid zinc, this reaction takes place at the <strong>cathode<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Thus, the <strong>half-reaction at the cathode is<\/strong>:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">$$<br>\\text{Zn}^{2+}(aq) + 2e^- \\rightarrow \\text{Zn}(s)<br>$$<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This matches the correct answer.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Conclusion:<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">In this galvanic cell, magnesium is the anode (oxidized), and zinc is the cathode (reduced). The cathode half-reaction is the <strong>reduction<\/strong> of Zn\u00b2\u207a ions to Zn metal:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">$$<br>\\boxed{\\text{Zn}^{2+}(aq) + 2e^- \\rightarrow \\text{Zn}(s)}<br>$$<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is the correct and balanced half-reaction at the cathode.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Designing a galvanic cell from a single-displacement redox reaction Suppose the galvanic cell sketched below is powered by the following reaction: Mg(s) + ZnCl2(aq) ? MgCl2(aq) + Zn(s) Write a balanced equation for the half-reaction that happens at the cathode of this cell. Zn2+(aq) + 2e- ? Zn(s) The Correct Answer and Explanation is: Correct [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[25],"tags":[],"class_list":["post-216070","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/216070","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/comments?post=216070"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/216070\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=216070"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=216070"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=216070"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}