{"id":232847,"date":"2025-06-12T09:16:40","date_gmt":"2025-06-12T09:16:40","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=232847"},"modified":"2025-06-12T09:16:42","modified_gmt":"2025-06-12T09:16:42","slug":"draw-an-energy-diagram-for-an-exothermic-reaction-that-yields-75-kcal-mol","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/06\/12\/draw-an-energy-diagram-for-an-exothermic-reaction-that-yields-75-kcal-mol\/","title":{"rendered":"Draw an energy diagram for an exothermic reaction that yields 75 kcal\/mol."},"content":{"rendered":"\n

Draw an energy diagram for an exothermic reaction that yields 75 kcal\/mol. The activation energy is 30KCal\/mole<\/p>\n\n\n\n

[Energy Diagram Description]<\/strong><\/p>\n\n\n\n

markdownCopyEditEnergy (kcal\/mol)\n   |\n 70|                            \u2021\n   |                           \/ \\\n   |                          \/   \\\n   |                         \/     \\\n 40|                        \/       \\\n   |                       \/         \\\n   |                      \/           \\\n   |                     \/             \\\n   |    Reactants       \/               \\    Products\n-35|-------------------\/                 \\-------------------\n   |\n   |_________________________________________________________\n                        Reaction Progress\n<\/code><\/pre>\n\n\n\n
\n\n\n\n
Explanation<\/h3>\n\n\n\n
In chemical thermodynamics, an energy diagram<\/strong> is a graphical representation that shows the energy changes during the course of a chemical reaction. It helps visualize the energy of the reactants<\/strong>, the transition state<\/strong>, and the energy of the products<\/strong>. For an exothermic reaction<\/strong>, energy is released to the surroundings, and the energy of the products is lower than that of the reactants.<\/p>\n\n\n\n
In this example, the reaction has a \u0394H (enthalpy change)<\/strong> of \u221275 kcal\/mol<\/strong>, meaning the products are 75 kcal\/mol lower in energy compared to the reactants. The activation energy (Ea)<\/strong> is 30 kcal\/mol<\/strong>, which is the energy barrier that must be overcome for the reactants to reach the transition state.<\/p>\n\n\n\n
The diagram begins with the reactants<\/strong> on the left at a certain energy level (say, 0 kcal\/mol for reference). The energy then increases as the reaction progresses, peaking at the transition state<\/strong>, which represents the highest energy point and is 30 kcal\/mol above<\/strong> the reactants. This peak indicates the unstable, high-energy intermediate configuration through which the molecules must pass.<\/p>\n\n\n\n
After reaching the transition state, the energy drops sharply, ending at the products<\/strong>, which are at \u221275 kcal\/mol<\/strong> relative to the reactants. This drop confirms that the reaction is exothermic<\/strong>. The large energy release implies a stable product, and the relatively low activation energy suggests that the reaction could proceed readily under appropriate conditions.<\/p>\n\n\n\n
This energy profile is crucial in predicting reaction spontaneity and rate. While \u0394H<\/strong> indicates thermodynamic favorability, the activation energy<\/strong> influences the reaction rate<\/strong>\u2014even exothermic reactions may proceed slowly if Ea is too high. Catalysts lower Ea, speeding up the reaction without altering \u0394H.<\/p>\n\n\n\n
\"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"
Draw an energy diagram for an exothermic reaction that yields 75 kcal\/mol. The activation energy is 30KCal\/mole [Energy Diagram Description] markdownCopyEditEnergy (kcal\/mol) | 70| \u2021 | \/ \\ | \/ \\ | \/ \\ 40| \/ \\ | \/ \\ | \/ \\ | \/ \\ | Reactants \/ \\ Products -35|——————-\/ \\——————- | |_________________________________________________________ […]<\/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-232847","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/232847","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=232847"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/232847\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=232847"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=232847"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=232847"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}