{"id":199585,"date":"2025-03-12T06:49:55","date_gmt":"2025-03-12T06:49:55","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=199585"},"modified":"2025-03-12T07:08:04","modified_gmt":"2025-03-12T07:08:04","slug":"consider-the-molecules-h2cch2-h2ccch2-and-h2cccch2","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/03\/12\/consider-the-molecules-h2cch2-h2ccch2-and-h2cccch2\/","title":{"rendered":"Consider the molecules H2CCH2, H2CCCH2, and H2CCCCH2"},"content":{"rendered":"\n<p>Consider the molecules H2CCH2, H2CCCH2, and H2CCCCH2. (a) Draw Lewis structures for these molecules. (b) What is the hybridization at each C atom? (c) What type of bond connects the carbon atoms (single, double, etc.)? (d) What are the HCH, CCH, and CCC angles in these molecules? (e) Do all the hydrogen atoms lie in the same plane? (f) A generalized formula for molecules of this type is H2C(C)xCH2, where x is 0, 1, 2, etc. What can be said, if anything, about the relative orientation of the H atoms at the ends of the chain as a function of x?<\/p>\n\n\n\n<p><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<h3 class=\"wp-block-heading\">(a) Lewis Structures:<\/h3>\n\n\n\n<p>The Lewis structures for the given molecules are:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Ethene (H\u2082C=CH\u2082)<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"wp-block-code\"><code>       H   H\n        \\ \/\n         C=C\n        \/ \\\n       H   H<\/code><\/pre>\n\n\n\n<ol start=\"2\" class=\"wp-block-list\">\n<li><strong>Allene (H\u2082C=C=CH\u2082)<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"wp-block-code\"><code>       H     H\n        \\   \/\n         C=C=C\n        \/   \\\n       H     H<\/code><\/pre>\n\n\n\n<ol start=\"3\" class=\"wp-block-list\">\n<li><strong>Butatriene (H\u2082C=C=C=CH\u2082)<\/strong><\/li>\n<\/ol>\n\n\n\n<pre class=\"wp-block-code\"><code>       H     H\n        \\   \/\n         C=C=C=C\n        \/   \\\n       H     H<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">(b) Hybridization:<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Ethene (H\u2082C=CH\u2082):<\/strong> Each carbon is <strong>sp\u00b2 hybridized<\/strong>.<\/li>\n\n\n\n<li><strong>Allene (H\u2082C=C=CH\u2082):<\/strong> The central carbon is <strong>sp hybridized<\/strong>, while the terminal carbons are <strong>sp\u00b2 hybridized<\/strong>.<\/li>\n\n\n\n<li><strong>Butatriene (H\u2082C=C=C=CH\u2082):<\/strong> The two inner carbons are <strong>sp hybridized<\/strong>, while the terminal carbons are <strong>sp\u00b2 hybridized<\/strong>.<\/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\">(c) Type of Bonds:<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Ethene (H\u2082C=CH\u2082):<\/strong> The two carbons are connected by a <strong>double bond (C=C)<\/strong>.<\/li>\n\n\n\n<li><strong>Allene (H\u2082C=C=CH\u2082):<\/strong> The terminal and central carbon atoms are connected by <strong>two double bonds (C=C=C)<\/strong>.<\/li>\n\n\n\n<li><strong>Butatriene (H\u2082C=C=C=CH\u2082):<\/strong> It has <strong>three consecutive double bonds (C=C=C=C)<\/strong>.<\/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\">(d) Bond Angles:<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Ethene (H\u2082C=CH\u2082):<\/strong> HCH \u2248 <strong>120\u00b0<\/strong>, CCH \u2248 <strong>120\u00b0<\/strong>.<\/li>\n\n\n\n<li><strong>Allene (H\u2082C=C=CH\u2082):<\/strong> HCH \u2248 <strong>120\u00b0<\/strong>, CCC \u2248 <strong>180\u00b0<\/strong>.<\/li>\n\n\n\n<li><strong>Butatriene (H\u2082C=C=C=CH\u2082):<\/strong> HCH \u2248 <strong>120\u00b0<\/strong>, CCC \u2248 <strong>180\u00b0<\/strong>.<\/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\">(e) Planarity of Hydrogen Atoms:<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Ethene:<\/strong> All hydrogen atoms lie in the <strong>same plane<\/strong>.<\/li>\n\n\n\n<li><strong>Allene:<\/strong> The two sets of hydrogen atoms on terminal carbons are <strong>perpendicular<\/strong> to each other.<\/li>\n\n\n\n<li><strong>Butatriene:<\/strong> The hydrogens at the terminal carbons are <strong>coplanar<\/strong>, but there is a twist as the chain grows longer.<\/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\">(f) General Formula H\u2082C(C)xCH\u2082:<\/h3>\n\n\n\n<p>As <strong>x increases<\/strong>, alternating hybridization leads to <strong>alternating planes<\/strong>. When x is even, the hydrogens at both ends are <strong>coplanar<\/strong>. When x is odd, they are in <strong>perpendicular planes<\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Illustration of Molecules<\/strong><\/h3>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" src=\"https:\/\/learnexams.com\/blog\/wp-content\/uploads\/2025\/03\/image-913.png\" alt=\"\" class=\"wp-image-199587\"\/><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>Consider the molecules H2CCH2, H2CCCH2, and H2CCCCH2. (a) Draw Lewis structures for these molecules. (b) What is the hybridization at each C atom? (c) What type of bond connects the carbon atoms (single, double, etc.)? (d) What are the HCH, CCH, and CCC angles in these molecules? (e) Do all the hydrogen atoms lie in [&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-199585","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/199585","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=199585"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/199585\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=199585"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=199585"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=199585"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}