{"id":209883,"date":"2025-04-29T13:24:09","date_gmt":"2025-04-29T13:24:09","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=209883"},"modified":"2025-04-29T13:24:11","modified_gmt":"2025-04-29T13:24:11","slug":"draw-the-pi-molecular-orbitals-of-butadiene","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/04\/29\/draw-the-pi-molecular-orbitals-of-butadiene\/","title":{"rendered":"Draw the pi-Molecular Orbitals of Butadiene"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">Draw the pi-Molecular Orbitals of Butadiene.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-6-color\"><strong>The correct answer and explanation is :<\/strong><\/mark><\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" src=\"https:\/\/sdmntpritalynorth.oaiusercontent.com\/files\/00000000-c410-6246-833a-cf8d9d7d68eb\/raw?se=2025-04-29T14%3A21%3A04Z&amp;sp=r&amp;sv=2024-08-04&amp;sr=b&amp;scid=74ddf86d-484f-531c-a1eb-67d9d84aa512&amp;skoid=06d77cea-897f-49c6-9d78-20f6510f72af&amp;sktid=a48cca56-e6da-484e-a814-9c849652bcb3&amp;skt=2025-04-29T05%3A57%3A47Z&amp;ske=2025-04-30T05%3A57%3A47Z&amp;sks=b&amp;skv=2024-08-04&amp;sig=hE8%2BlwfvlH7%2B1JSco1T%2BWONNl4%2BV2tzetMQMpl1EhGY%3D\"\/><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\">Correct Answer:<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Butadiene has <strong>four \u03c0 molecular orbitals<\/strong> formed from the four p-orbitals on the carbon atoms involved in the \u03c0 system. These molecular orbitals are:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u03c0\u2081 (lowest energy, bonding)<\/li>\n\n\n\n<li>\u03c0\u2082 (bonding)<\/li>\n\n\n\n<li>\u03c0\u2083* (antibonding)<\/li>\n\n\n\n<li>\u03c0\u2084* (highest energy, antibonding)<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The <strong>two lowest-energy orbitals (\u03c0\u2081 and \u03c0\u2082)<\/strong> are filled with the four \u03c0 electrons of butadiene, and the <strong>higher-energy orbitals (\u03c0\u2083* and \u03c0\u2084*)<\/strong> remain unoccupied in the ground state.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Explanation (300+ words):<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Butadiene (CH\u2082=CH\u2013CH=CH\u2082) is a conjugated diene with four carbon atoms connected by alternating single and double bonds. Each carbon atom in the \u03c0-system has a <strong>p-orbital<\/strong> that can participate in \u03c0 bonding, resulting in the formation of <strong>molecular orbitals (MOs)<\/strong> by the linear combination of atomic p-orbitals.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In molecular orbital theory, these four p-orbitals combine to form <strong>four \u03c0 molecular orbitals<\/strong>:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>\u03c0\u2081<\/strong> \u2013 the lowest energy orbital, with all four p-orbitals in-phase (bonding).<\/li>\n\n\n\n<li><strong>\u03c0\u2082<\/strong> \u2013 one node, still bonding but higher in energy than \u03c0\u2081.<\/li>\n\n\n\n<li><strong>\u03c0\u2083<\/strong>* \u2013 two nodes, antibonding.<\/li>\n\n\n\n<li><strong>\u03c0\u2084<\/strong>* \u2013 three nodes, the highest energy and most antibonding.<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">Each molecular orbital can hold two electrons. Butadiene has four \u03c0 electrons in total (one from each of the four sp\u00b2-hybridized carbon atoms). In the ground state, these electrons fill the two lowest-energy \u03c0 orbitals:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u03c0\u2081 (2 electrons)<\/strong><\/li>\n\n\n\n<li><strong>\u03c0\u2082 (2 electrons)<\/strong><\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">The <strong>\u03c0\u2083* and \u03c0\u2084<\/strong>* orbitals remain <strong>empty<\/strong> in the ground state. This electron configuration contributes to the <strong>stability of conjugated systems<\/strong>, as the electrons occupy lower-energy bonding molecular orbitals.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">An important feature of butadiene\u2019s molecular orbital diagram is that the <strong>energy gap between \u03c0\u2082 and \u03c0\u2083<\/strong>* is relatively small compared to the gap between \u03c0\u2081 and \u03c0\u2082, which influences its <strong>UV-Vis absorption<\/strong> properties. This small energy gap allows for \u03c0 \u2192 \u03c0* transitions at longer wavelengths, making conjugated systems like butadiene capable of absorbing visible or near-UV light.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Understanding the \u03c0 molecular orbitals in butadiene helps explain its chemical reactivity (e.g., in Diels-Alder reactions), electronic transitions, and the general concept of delocalized bonding in conjugated systems.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Draw the pi-Molecular Orbitals of Butadiene. The correct answer and explanation is : Correct Answer: Butadiene has four \u03c0 molecular orbitals formed from the four p-orbitals on the carbon atoms involved in the \u03c0 system. These molecular orbitals are: The two lowest-energy orbitals (\u03c0\u2081 and \u03c0\u2082) are filled with the four \u03c0 electrons of butadiene, [&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-209883","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/209883","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=209883"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/209883\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=209883"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=209883"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=209883"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}