{"id":222024,"date":"2025-05-30T19:56:27","date_gmt":"2025-05-30T19:56:27","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=222024"},"modified":"2025-05-30T19:56:29","modified_gmt":"2025-05-30T19:56:29","slug":"the-specific-rotation-of-carvone-is-61-degrees-while-the-specific-rotation-of-r-carvone-is-61-degrees","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/05\/30\/the-specific-rotation-of-carvone-is-61-degrees-while-the-specific-rotation-of-r-carvone-is-61-degrees\/","title":{"rendered":"The specific rotation of -Carvone is +61 degrees, while the specific rotation of (R)-Carvone is -61 degrees"},"content":{"rendered":"\n
The specific rotation of -Carvone is +61 degrees, while the specific rotation of (R)-Carvone is -61 degrees. If a sample of mixture of the two enantiomers has a specific rotation of -40.58 degrees<\/p>\n\n\n\n
Part I. What is the percent enantiomeric excess of the mixture? a) +24.75 b) -24.75 c) 24.75 d) -66.52 e) 66.52<\/p>\n\n\n\n
Part II. What is the percentage of each enantiomer in the above mixture? a) of and of S b) of and of c) of and of d) racemic mixture of and e) of and of<\/p>\n\n\n\n
The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n
Part I: What is the percent enantiomeric excess (ee)?<\/strong><\/h3>\n\n\n\n
We are given:<\/p>\n\n\n\n
\n
Specific rotation of pure (S)-Carvone<\/strong>: +61\u00b0<\/strong><\/li>\n\n\n\n
Specific rotation of pure (R)-Carvone<\/strong>: \u201361\u00b0<\/strong><\/li>\n\n\n\n
Specific rotation of the mixture<\/strong>: \u201340.58\u00b0<\/strong><\/li>\n<\/ul>\n\n\n\n
The formula for enantiomeric excess (ee)<\/strong> is: ee=(observed rotationrotation of pure enantiomer)\u00d7100%ee = \\left( \\frac{\\text{observed rotation}}{\\text{rotation of pure enantiomer}} \\right) \\times 100\\%<\/p>\n\n\n\n
Since the observed rotation is negative, we take the value for (R)-Carvone as the pure enantiomer reference: ee=(\u221240.58\u221261)\u00d7100%=66.52%ee = \\left( \\frac{-40.58}{-61} \\right) \\times 100\\% = 66.52\\%<\/p>\n\n\n\n
\u2705 Correct answer for Part I: e) 66.52<\/strong><\/p>\n\n\n\n\n\n\n\n
Part II: What is the percentage of each enantiomer?<\/strong><\/h3>\n\n\n\n
Enantiomeric excess (ee) also means the excess percentage of one enantiomer over the racemic mixture<\/strong>. That is: ee=%major enantiomer\u2212%minor enantiomer\\text{ee} = \\% \\text{major enantiomer} – \\% \\text{minor enantiomer}<\/p>\n\n\n\n
And since the total must be 100%: %major+%minor=100%\\% \\text{major} + \\% \\text{minor} = 100\\%<\/p>\n\n\n\n
So the correct answer for Part II<\/strong> is:<\/p>\n\n\n\n
e) 83.26% of (R) and 16.74% of (S)<\/strong><\/p>\n\n\n\n\n\n\n\n
\u2705 Final Answers:<\/h3>\n\n\n\n
\n
Part I:<\/strong> e) 66.52<\/strong><\/li>\n\n\n\n
Part II:<\/strong> e) 83.26% of (R) and 16.74% of (S)<\/strong><\/li>\n<\/ul>\n\n\n\n<\/figure>\n","protected":false},"excerpt":{"rendered":"
The specific rotation of -Carvone is +61 degrees, while the specific rotation of (R)-Carvone is -61 degrees. If a sample of mixture of the two enantiomers has a specific rotation of -40.58 degrees Part I. What is the percent enantiomeric excess of the mixture?a) +24.75b) -24.75c) 24.75d) -66.52e) 66.52 Part II. What is the percentage […]<\/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-222024","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/222024","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=222024"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/222024\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=222024"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=222024"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=222024"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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