{"id":216301,"date":"2025-05-19T04:21:33","date_gmt":"2025-05-19T04:21:33","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=216301"},"modified":"2025-05-19T04:21:35","modified_gmt":"2025-05-19T04:21:35","slug":"you-are-employed-at-phenomenal-phenols-inc-and-have-been-asked-by-your-supervisor-o-h-gruppa-to-identify-a-compound-a-that-was-isolated-from-natural-sources","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/05\/19\/you-are-employed-at-phenomenal-phenols-inc-and-have-been-asked-by-your-supervisor-o-h-gruppa-to-identify-a-compound-a-that-was-isolated-from-natural-sources\/","title":{"rendered":"You are employed at Phenomenal Phenols, Inc., and have been asked by your Supervisor, O. H. Gruppa, to identify a compound A that was isolated from natural sources"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">You are employed at Phenomenal Phenols, Inc., and have been asked by your Supervisor, O. H. Gruppa, to identify a compound A that was isolated from natural sources. Compound A, mp 129\ufffd130 \ufffdC, is soluble in NaOH solution and in hot water. The IR spectrum of A shows prominent absorptions at 3300\ufffd3600 cm\ufffd1 (broad) and 1680 cm\ufffd1; the EI mass spectrum of A has prominent peaks at m\/z = 166 and 107, and the CI mass spectrum has an M 1 peak at m\/z =167. The NMR spectrum of A is given below. Titration determined that A has two acidic groups with pKa values of 4.7 and 10.4. The UV spectrum of A is virtually unchanged as the pH of a solution of A is raised from 2 to 7, but the ?max shifts to much higher wavelength when A is dissolved in 0.1 M NaOH solution.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-1-color\">The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Based on the data provided, <strong>compound A is <em>gallic acid<\/em> (3,4,5-trihydroxybenzoic acid)<\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 <strong>Explanation (Approx. 300+ Words)<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">To identify compound A, we analyze the various pieces of spectral and chemical information:<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\ud83d\udd2c <strong>1. Melting Point and Solubility:<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Melting point<\/strong>: 129\u2013130\u202f\u00b0C \u2014 consistent with gallic acid.<\/li>\n\n\n\n<li><strong>Solubility<\/strong>: Soluble in <strong>NaOH<\/strong> and <strong>hot water<\/strong> \u2192 this indicates <strong>acidic functional groups<\/strong>, likely <strong>phenolic<\/strong> and <strong>carboxylic<\/strong> groups.<\/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\">\ud83d\udcc9 <strong>2. IR Spectrum:<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>3300\u20133600 cm\u207b\u00b9 (broad)<\/strong>: Indicates <strong>O\u2013H<\/strong> stretching, typical of <strong>hydroxyl<\/strong> groups (especially <strong>phenols<\/strong>).<\/li>\n\n\n\n<li><strong>1680 cm\u207b\u00b9<\/strong>: Suggests <strong>C=O<\/strong> stretching, typical of a <strong>carboxylic acid<\/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\">\ud83d\udca5 <strong>3. Mass Spectrometry:<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>EI-MS:<\/strong><\/li>\n\n\n\n<li><strong>m\/z = 166<\/strong> \u2192 Likely the <strong>molecular ion (M\u207a)<\/strong>.<\/li>\n\n\n\n<li><strong>m\/z = 107<\/strong> \u2192 A common fragment ion, possibly due to <strong>loss of COOH group<\/strong>.<\/li>\n\n\n\n<li><strong>CI-MS:<\/strong><\/li>\n\n\n\n<li><strong>m\/z = 167<\/strong> \u2192 M + 1 peak (supports MW of <strong>166 g\/mol<\/strong>).<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">This mass is consistent with <strong>gallic acid (C\u2087H\u2086O\u2085)<\/strong>:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Molar mass: 170 g\/mol (but often loses water or COOH in fragmentation).<\/li>\n\n\n\n<li>Exact mass from formula <strong>C\u2087H\u2086O\u2085<\/strong> = <strong>170.12 g\/mol<\/strong>, with possible loss of small neutral molecules in EI-MS (explaining m\/z = 166).<\/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\">\ud83d\udcca <strong>4. NMR Spectrum:<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Although the NMR spectrum isn\u2019t provided in full detail here, gallic acid typically shows:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Aromatic protons<\/strong> as a <strong>singlet<\/strong> due to symmetric substitution (only <strong>2 protons<\/strong> on benzene ring).<\/li>\n\n\n\n<li><strong>Broad signals<\/strong> from <strong>hydroxyl protons<\/strong> (OH groups).<\/li>\n\n\n\n<li><strong>Downfield peak<\/strong> (~12 ppm) from <strong>COOH proton<\/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\">\u2697\ufe0f <strong>5. Acidity (pKa values):<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>pKa = 4.7<\/strong> \u2192 consistent with <strong>carboxylic acid<\/strong> group.<\/li>\n\n\n\n<li><strong>pKa = 10.4<\/strong> \u2192 typical for <strong>phenol OH<\/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\">\ud83c\udf08 <strong>6. UV-Visible Spectrum:<\/strong><\/h3>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 <strong>Conclusion:<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">All the evidence \u2014 mass (m\/z 166), IR (O\u2013H, C=O), solubility, UV shift in base, and acidity profile \u2014 points strongly to <strong>gallic acid<\/strong> as <strong>compound A<\/strong>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>You are employed at Phenomenal Phenols, Inc., and have been asked by your Supervisor, O. H. Gruppa, to identify a compound A that was isolated from natural sources. Compound A, mp 129\ufffd130 \ufffdC, is soluble in NaOH solution and in hot water. The IR spectrum of A shows prominent absorptions at 3300\ufffd3600 cm\ufffd1 (broad) and [&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-216301","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/216301","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=216301"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/216301\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=216301"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=216301"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=216301"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}