{"id":186668,"date":"2025-01-26T05:42:44","date_gmt":"2025-01-26T05:42:44","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=186668"},"modified":"2025-01-26T05:42:46","modified_gmt":"2025-01-26T05:42:46","slug":"calculate-the-index-of-hydrogen-deficiency-degrees-of-unsaturation-for-the-following-molecule-with-molecular-formula-c5h1002","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/01\/26\/calculate-the-index-of-hydrogen-deficiency-degrees-of-unsaturation-for-the-following-molecule-with-molecular-formula-c5h1002\/","title":{"rendered":"Calculate the index of hydrogen deficiency (degrees of unsaturation) for the following molecule with molecular formula C5H1002"},"content":{"rendered":"\n<p>Calculate the index of hydrogen deficiency (degrees of unsaturation) for the following molecule with molecular formula C5H1002, and propose a structure for this compound consistent with the following IR, H NMR, and 23C NMR.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" src=\"https:\/\/learnexams.com\/blog\/wp-content\/uploads\/2025\/01\/image-474.png\" alt=\"\" class=\"wp-image-186669\"\/><\/figure>\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<p>\ue203The molecular formula C\u2085H\u2081\u2080O\u2082 indicates a compound with five carbon atoms, ten hydrogen atoms, and two oxygen atoms.\ue204 To determine the Index of Hydrogen Deficiency (IHD), we use the formula:\ue206<\/p>\n\n\n\n<p>\ue203<strong>IHD = (2C + 2 &#8211; H) \/ 2<\/strong>\ue204\ue206<\/p>\n\n\n\n<p>\ue203Substituting the given values:\ue204\ue206<\/p>\n\n\n\n<p>\ue203<strong>IHD = (2(5) + 2 &#8211; 10) \/ 2 = (10 + 2 &#8211; 10) \/ 2 = 2 \/ 2 = 1<\/strong>\ue204\ue206<\/p>\n\n\n\n<p>\ue203An IHD of 1 suggests the presence of either one ring or one double bond in the compound.\ue204\ue206<\/p>\n\n\n\n<p>\ue203Given the molecular formula and IHD, a plausible structure is <strong>pentanoic acid (valeric acid)<\/strong>.\ue204\ue206<\/p>\n\n\n\n<p><strong>Proposed Structure:<\/strong><\/p>\n\n\n\n<p>\ue203Pentanoic acid consists of a five-carbon chain with a carboxyl group (-COOH) at one end.\ue204\ue206<\/p>\n\n\n\n<p><strong>Explanation:<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Degree of Unsaturation:<\/strong> \ue203The IHD calculation indicates one degree of unsaturation, which corresponds to the carboxyl group (-COOH) in pentanoic acid.\ue204\ue206<\/li>\n\n\n\n<li><strong>IR Spectrum:<\/strong> \ue203The IR spectrum of pentanoic acid typically shows a strong, broad absorption around 2500\u20133300 cm\u207b\u00b9 due to the O-H stretch of the carboxyl group, and a sharp absorption near 1700 cm\u207b\u00b9 for the C=O stretch.\ue204\ue206<\/li>\n\n\n\n<li><strong>\u00b9H NMR Spectrum:<\/strong> \ue203In the \u00b9H NMR spectrum, pentanoic acid exhibits:\ue204\ue206\n<ul class=\"wp-block-list\">\n<li>\ue203A broad singlet around 11\u201312 ppm for the carboxylic acid proton.\ue204\ue206<\/li>\n\n\n\n<li>\ue203Multiplets between 2\u20133 ppm for the methylene protons adjacent to the carboxyl group.\ue204\ue206<\/li>\n\n\n\n<li>\ue203Multiplets between 1\u20132 ppm for the remaining methylene protons in the chain.\ue204\ue206<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>\u00b9\u00b3C NMR Spectrum:<\/strong> \ue203The \u00b9\u00b3C NMR spectrum shows:\ue204\ue206\n<ul class=\"wp-block-list\">\n<li>\ue203A carbonyl carbon signal around 180 ppm.\ue204\ue206<\/li>\n\n\n\n<li>\ue203Methylene carbon signals between 30\u201340 ppm.\ue204\ue206<\/li>\n\n\n\n<li>\ue203Methyl carbon signals around 10\u201320 ppm.\ue204\ue206<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n\n\n\n<p>\ue203These spectral features are consistent with the structure of pentanoic acid.\ue204\ue206<\/p>\n\n\n\n<p>For a visual explanation of the \u00b9H NMR spectrum of C\u2085H\u2081\u2080O\u2082, you might find the following video helpful:<\/p>\n\n\n\n<p>\ue200video\ue202\u00b9H NMR of C\u2085H\u2081\u2080O\u2082 (pentanoic acid, valeric acid)\ue202turn0search6\ue201<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Calculate the index of hydrogen deficiency (degrees of unsaturation) for the following molecule with molecular formula C5H1002, and propose a structure for this compound consistent with the following IR, H NMR, and 23C NMR. The Correct Answer and Explanation is : \ue203The molecular formula C\u2085H\u2081\u2080O\u2082 indicates a compound with five carbon atoms, ten hydrogen atoms, [&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-186668","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/186668","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=186668"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/186668\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=186668"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=186668"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=186668"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}