{"id":248816,"date":"2025-07-08T18:39:18","date_gmt":"2025-07-08T18:39:18","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=248816"},"modified":"2025-07-08T18:39:20","modified_gmt":"2025-07-08T18:39:20","slug":"consider-the-ir-spectrum-of-an-unknown-compound","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/07\/08\/consider-the-ir-spectrum-of-an-unknown-compound\/","title":{"rendered":"Consider the IR spectrum of an unknown compound"},"content":{"rendered":"\n

Consider the IR spectrum of an unknown compound. Which compound matches the IR spectrum best? D B C E F A<\/p>\n\n\n\n

The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n

To determine which compound matches an IR spectrum best, it’s important to look for specific peaks and their corresponding functional groups. Each type of bond absorbs infrared radiation at characteristic frequencies, leading to distinct peaks in the IR spectrum.<\/p>\n\n\n\n

Typically, here\u2019s what you should focus on:<\/p>\n\n\n\n

    \n
  1. O-H Stretch<\/strong>: A broad, strong peak around 3200-3550 cm\u207b\u00b9 suggests the presence of a hydroxyl group (alcohols or phenols).<\/li>\n\n\n\n
  2. N-H Stretch<\/strong>: A moderate peak around 3300-3500 cm\u207b\u00b9 could indicate an amine or amide.<\/li>\n\n\n\n
  3. C=O Stretch<\/strong>: A sharp, strong peak around 1725 cm\u207b\u00b9 generally indicates the presence of a carbonyl group, which is found in aldehydes, ketones, carboxylic acids, and esters.<\/li>\n\n\n\n
  4. C-H Stretch<\/strong>: Alkanes show peaks around 2850-2960 cm\u207b\u00b9, alkenes near 3080 cm\u207b\u00b9, and alkynes around 3300 cm\u207b\u00b9.<\/li>\n\n\n\n
  5. C=C Stretch<\/strong>: Alkenes show peaks between 1600-1680 cm\u207b\u00b9, with conjugation lowering this stretch to lower frequencies.<\/li>\n\n\n\n
  6. Fingerprint Region<\/strong>: Below 1500 cm\u207b\u00b9, unique bonds and vibrations of the molecule appear. These can help identify the compound further.<\/li>\n<\/ol>\n\n\n\n

    Given this, to match the IR spectrum with the unknown compound, you would need to match the observed peaks with these characteristic absorptions. For example, if the spectrum shows a broad peak around 3400 cm\u207b\u00b9 and a strong peak around 1725 cm\u207b\u00b9, the compound might be a carboxylic acid (C=O stretch and O-H stretch).<\/p>\n\n\n\n

    Unfortunately, I\u2019d need more specific details about the IR spectrum you’re analyzing to give a direct answer. If you provide the spectrum\u2019s key peaks, I can help narrow it down further.<\/p>\n\n\n\n

    \"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

    Consider the IR spectrum of an unknown compound. Which compound matches the IR spectrum best? D B C E F A The Correct Answer and Explanation is: To determine which compound matches an IR spectrum best, it’s important to look for specific peaks and their corresponding functional groups. Each type of bond absorbs infrared radiation […]<\/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-248816","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/248816","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=248816"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/248816\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=248816"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=248816"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=248816"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}