{"id":258893,"date":"2025-07-18T14:42:43","date_gmt":"2025-07-18T14:42:43","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=258893"},"modified":"2025-07-18T14:42:47","modified_gmt":"2025-07-18T14:42:47","slug":"benzophenone-starting-material","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/07\/18\/benzophenone-starting-material\/","title":{"rendered":"Benzophenone starting material"},"content":{"rendered":"\n

Benzophenone starting material INFRARED SPECTRUM 0.8 L 0.6 1 0.2 3000 2000 Wavenumber (cm-1) 1000<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

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

Correct Answer:<\/strong> The infrared spectrum confirms the structure of benzophenone. Key absorptions include aromatic C-H stretches above 3000 cm\u207b\u00b9, a strong carbonyl (C=O) stretch at approximately 1660 cm\u207b\u00b9, aromatic C=C stretches between 1450-1600 cm\u207b\u00b9, and C-H bending vibrations below 900 cm\u207b\u00b9.<\/p>\n\n\n\n

Explanation:<\/strong><\/p>\n\n\n\n

The provided infrared (IR) spectrum is consistent with the molecular structure of benzophenone, which consists of a central carbonyl group bonded to two phenyl rings. The analysis of specific absorption peaks confirms the presence of the key functional groups.<\/p>\n\n\n\n

The region just above 3000 cm\u207b\u00b9 shows several sharp peaks, which are characteristic of the C-H stretching vibrations of sp2-hybridized carbons in an aromatic ring. The absence of peaks in the 2850-3000 cm\u207b\u00b9 range confirms the lack of aliphatic sp3-hybridized C-H bonds.<\/p>\n\n\n\n

The most diagnostic and intense peak in this spectrum is the sharp absorption at approximately 1660 cm\u207b\u00b9. This signal is characteristic of a carbonyl (C=O) stretching vibration. The position of this peak is lower than that of a typical saturated ketone (around 1715 cm\u207b\u00b9) due to conjugation. The delocalization of electrons between the carbonyl group and the two attached aromatic rings weakens the C=O double bond, requiring less energy to stretch and thus lowering its absorption frequency. This is a hallmark of an aromatic ketone.<\/p>\n\n\n\n

Additionally, the spectrum displays several absorptions in the 1450-1600 cm\u207b\u00b9 range. These peaks are attributed to the C=C stretching vibrations within the aromatic rings themselves, further supporting the presence of the phenyl groups.<\/p>\n\n\n\n

Finally, the fingerprint region below 1500 cm\u207b\u00b9 provides more structural information. The strong, sharp peaks observed around 700 cm\u207b\u00b9 and 750 cm\u207b\u00b9 are typical for the out-of-plane C-H bending vibrations of a monosubstituted benzene ring. The presence of these absorptions strongly suggests this substitution pattern. The lack of a broad peak in the 3200-3600 cm\u207b\u00b9 region confirms the absence of any hydroxyl (O-H) groups. In summary, all the observed spectral features align perfectly with the structure of benzophenone.<\/p>\n\n\n\n

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

Benzophenone starting material INFRARED SPECTRUM 0.8 L 0.6 1 0.2 3000 2000 Wavenumber (cm-1) 1000 The Correct Answer and Explanation is: Correct Answer: The infrared spectrum confirms the structure of benzophenone. Key absorptions include aromatic C-H stretches above 3000 cm\u207b\u00b9, a strong carbonyl (C=O) stretch at approximately 1660 cm\u207b\u00b9, aromatic C=C stretches between 1450-1600 cm\u207b\u00b9, and […]<\/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-258893","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/258893","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=258893"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/258893\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=258893"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=258893"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=258893"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}