{"id":59539,"date":"2016-03-25T17:20:03","date_gmt":"2016-03-25T15:20:03","guid":{"rendered":"http:\/\/wpcalc.com\/?p=59539"},"modified":"2026-09-29T14:57:46","modified_gmt":"2026-09-29T11:57:46","slug":"balancing-redox-reactions-2","status":"publish","type":"post","link":"https:\/\/wpcalc.com\/en\/chemistry\/balancing-redox-reactions-2\/","title":{"rendered":"Balancing Redox Reactions"},"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\">Balance Your Redox Equation<\/h2><\/div><div class=\"calcdash-favorite group\">\n  <button type=\"button\" class=\"favorite\" id=\"favorite\" data-favorite-id=\"59539\" data-favorite-title=\"Balancing Redox Reactions\" data-favorite-url=\"https:\/\/wpcalc.com\/en\/chemistry\/balancing-redox-reactions-2\/\" data-favorite-excerpt=\"Balance a redox equation by entering its reactants and products, including ionic charges. The calculator finds coefficients that conserve both atoms and charge.\" aria-label=\"Add to Favorites\" 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\/en\/chemistry\/balancing-redox-reactions-2\/\" method=\"POST\" class=\"calculator\" id=\"calculator-59539\" data-post=\"59539\"><fieldset class=\"fieldset-input\"><legend class=\"sr-only\">Input Fields<\/legend><div class=\"field is-single\" id=\"input-1\"><label for=\"field-1\">Enter the redox reaction<\/label><input type=\"text\" name=\"enter_the_redox_reaction\" id=\"field-1\" aria-describedby=\"calc-info-1\" placeholder=\"e.g. MnO4^- + Fe^2+ = Mn^2+ + Fe^3+\" step=\"any\" value=\"S^2- + I2 = I^- + S\"\/><small id=\"calc-info-1\">Use ^ for charges, + to separate species, = for the reaction arrow. Example: Cr2O7^2- + H^+ + e^- = Cr^3+ + H2O<\/small><\/div><\/fieldset><div class=\"buttons\"><button type=\"submit\" data-text=\"Re-Calculate\" id=\"calculate-button\" data-post=\"59539\">Calculate<\/button><button type=\"reset\">Reset<\/button><\/div><div class=\"field is-checkbox hidden!\" id=\"field-auto-calc\"><input type=\"checkbox\" id=\"auto-calc\"><label for=\"auto-calc\">Calculate automatically<\/label><small>If enabled, the result will update automatically when you change any value.<\/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> Your Results<\/h3><div class=\"result-box\"><div class=\"field-result is-borderless\" id=\"output-1\"><span class=\"field-value\" id=\"result\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copy Result\" aria-label=\"Copy Result\"><span class=\"copy-icon icon icon-document-copy\" aria-hidden=\"true\"><\/span><\/button><\/div><div class=\"field-result is-borderless\" id=\"output-2\"><span class=\"field-value\" id=\"message\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copy Result\" aria-label=\"Copy Result\"><span class=\"copy-icon icon icon-document-copy\" aria-hidden=\"true\"><\/span><\/button><\/div><div class=\"field-result is-borderless\" id=\"output-3\"><span class=\"field-value\" id=\"codevalid\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copy Result\" aria-label=\"Copy Result\"><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\">Copy link to this calculation<\/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>Leave a Comment<\/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=\"59539\" aria-live=\"polite\" aria-labelledby=\"calc-reactions-title\"><p id=\"calc-reactions-title\" class=\"text-sm text-gray-500 text-center mb-2\">How did this result make you feel?<\/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\">3<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\ude00 <\/span><span class=\"reaction-description font-medium\">Like <\/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\">1<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\udca1 <\/span><span class=\"reaction-description font-medium\">Helpful <\/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\">3<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\ude15 <\/span><span class=\"reaction-description font-medium\">Confused <\/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\">23<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\ude1e <\/span><span class=\"reaction-description font-medium\">Disappointed <\/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\">16<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\u274c <\/span><span class=\"reaction-description font-medium\">Inaccurate <\/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>Balancing Redox Reactions Formula<\/h2><\/div>\r\n\t<figure class=\"not-prose formula\">\r\n\t\t<figcaption class=\"formula-title\">Formula<\/figcaption>\r\n\t\t<div class=\"text-base text-gray-800\" id=\"formula\">\n\\[\\sum_{i\\in L}c_i n_{i,E}=\\sum_{j\\in R}c_j n_{j,E}\\quad\\text{for every element }E\\]\n\\[\\sum_{i\\in L}c_i q_i=\\sum_{j\\in R}c_j q_j\\]\n<\/div>\r\n\t<\/figure>\r\n\t<\/p>\n<p><strong>Where:<\/strong><\/p>\n<ul>\n<li>\\(L\\) and \\(R\\) \u2014 the reactants and products entered in the equation.<\/li>\n<li>\\(c_i\\) \u2014 the coefficient of a species.<\/li>\n<li>\\(n_{i,E}\\) \u2014 the number of atoms of element \\(E\\) in that species.<\/li>\n<li>\\(q_i\\) \u2014 the species\u2019 signed electric charge.<\/li>\n<\/ul>\n<p>A balanced equation has the same number of each type of atom and the same total charge on both sides. The calculator solves these conservation conditions for the coefficients of the species you enter.<\/p>\n<p>\r\n<\/section>\n<style id=\"wpcoderpro-inline-459\">.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>Balancing Redox Reactions \u2013 Calculation Example<\/h2><\/div>\r\n\r\n<\/p>\n<p><strong>Example:<\/strong> balance the calculator\u2019s default reaction, <code>S^2- + I2 = I^- + S<\/code>. Sulfide loses two electrons to form sulfur, while iodine gains two electrons to form iodide.<\/p>\n<p>\\[\\begin{aligned}\\mathrm{S}^{2-}&amp;\\rightarrow\\mathrm{S}+2e^-\\\\\\mathrm{I}_2+2e^-&amp;\\rightarrow 2\\mathrm{I}^-\\end{aligned}\\]<\/p>\n<p>Adding the two changes cancels the electrons. There is one sulfur atom and two iodine atoms on each side; the total charge is \\(-2\\) on each side.<\/p>\n<p>\\[\\mathrm{S}^{2-}+\\mathrm{I}_2\\rightarrow 2\\mathrm{I}^-+\\mathrm{S}\\]<\/p>\n<p><strong>Result:<\/strong> the coefficients are 1, 1, 2, and 1, in the order entered.<\/p>\n<p>\n\r\n<\/section>\n<h2>How to use the calculator<\/h2>\n<ol>\n<li>In <strong>Enter the redox reaction<\/strong>, type the reactants, an equals sign, and the products. For example: <code>S^2- + I2 = I^- + S<\/code>.<\/li>\n<li>Use <code>+<\/code> between species and <code>=<\/code> for the reaction arrow. Write atom counts as ordinary numbers, such as <code>I2<\/code> or <code>H2O<\/code>.<\/li>\n<li>Write ionic charges with a caret followed by the magnitude, if needed, and the sign: <code>Fe^2+<\/code>, <code>MnO4^-<\/code>, or <code>H^+<\/code>. You can enter <code>e^-<\/code> when balancing a half-reaction.<\/li>\n<li>Run the calculation and read the balanced equation. Check that its species match your intended reaction; any message below the result may identify an input or balancing problem.<\/li>\n<\/ol>\n<p>Enter every required reactant and product yourself. If a reaction needs water, hydrogen ions, or hydroxide ions, include them on the appropriate side before calculating. For example, an acidic permanganate reaction may need both <code>H^+<\/code> and <code>H2O<\/code>; the calculator does not add them automatically.<\/p>\n<h2>What a balanced redox equation means<\/h2>\n<p>A redox reaction transfers electrons between chemical species. <strong>Oxidation<\/strong> is electron loss, and <strong>reduction<\/strong> is electron gain. In the example above, sulfide is oxidized to sulfur and iodine is reduced to iodide. The electrons lost and gained must be equal, even when electrons do not appear in the final overall equation.<\/p>\n<p>Coefficients state the relative amounts of the species taking part; they do not change the composition of a species. For instance, the 2 before \\(\\mathrm{I}^-\\) means two iodide ions, whereas the 2 in \\(\\mathrm{I}_2\\) means two iodine atoms within each iodine molecule. Charge must balance as well as atoms: matching atom counts alone can leave an ionic equation incorrect.<\/p>\n<p>The calculator uses the formulas and charges you supply to find coefficients that satisfy those conservation rules. It does not determine oxidation states or show the half-reaction steps. For a reaction involving only neutral species, use the <a href=\"https:\/\/wpcalc.com\/en\/chemistry\/balancing-chemical-equations\/\">Chemical Equation Balancer<\/a> instead. Once an equation is balanced, its coefficients can be used as mole ratios; the <a href=\"https:\/\/wpcalc.com\/en\/chemistry\/convert-atoms-to-moles\/\">Atoms to Moles Calculator<\/a> can help convert particle counts for a subsequent calculation.<\/p>\n<h2>Assumptions and practical limits<\/h2>\n<ul>\n<li><strong>Specify the medium through the equation.<\/strong> The calculator does not detect acidic or basic conditions. Include \\(\\mathrm{H}^+\\) and \\(\\mathrm{H}_2\\mathrm{O}\\) for an appropriate acidic equation, or \\(\\mathrm{OH}^-\\) and \\(\\mathrm{H}_2\\mathrm{O}\\) for an appropriate basic equation.<\/li>\n<li><strong>Use the stated input format.<\/strong> Type plain chemical formulas rather than formatted subscripts or superscripts. Use <code>=<\/code>, not an arrow, between the two sides.<\/li>\n<li><strong>Check the proposed chemistry.<\/strong> Balancing confirms conservation for the entered species; it cannot establish that a reaction occurs or that the products are chemically appropriate.<\/li>\n<li><strong>Resolve errors by checking the species list.<\/strong> A missing product, an incorrect charge, or an equation with more than one possible coefficient set may prevent a unique result. This calculator is intended for ionic redox equations and may reject a neutral species entered before any ion.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Balance a redox equation by entering its reactants and products, including ionic charges. The calculator finds coefficients that conserve both atoms and charge.<\/p>\n","protected":false},"author":70,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[54],"tags":[57],"class_list":["post-59539","post","type-post","status-publish","format-standard","hentry","category-chemistry","tag-reactions"],"acf":[],"_links":{"self":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/59539","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/users\/70"}],"replies":[{"embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/comments?post=59539"}],"version-history":[{"count":5,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/59539\/revisions"}],"predecessor-version":[{"id":65556,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/59539\/revisions\/65556"}],"wp:attachment":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/media?parent=59539"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/categories?post=59539"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/tags?post=59539"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}