{"id":257082,"date":"2025-07-16T17:59:13","date_gmt":"2025-07-16T17:59:13","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=257082"},"modified":"2025-07-16T17:59:15","modified_gmt":"2025-07-16T17:59:15","slug":"the-molecular-mass-of-propane-12-diol-is-76-1-amu-2","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/07\/16\/the-molecular-mass-of-propane-12-diol-is-76-1-amu-2\/","title":{"rendered":"The molecular mass of propane-1,2-diol is 76.1 amu ."},"content":{"rendered":"\n<p>The molecular mass of propane-1,2-diol is 76.1 amu . Calculate the molecular mass of propane-1,3-diol, an isomer of propane-1,2-diol.<\/p>\n\n\n\n<p><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>The molecular mass of propane-1,2-diol is given as 76.1 amu. Now, we need to calculate the molecular mass of propane-1,3-diol, an isomer of propane-1,2-diol.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Molecular Structure<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Propane-1,2-diol (also known as 1,2-propanediol)<\/strong> has the structure:<br>CH\u2082OH-CH(OH)-CH\u2083<\/li>\n\n\n\n<li><strong>Propane-1,3-diol (also known as 1,3-propanediol)<\/strong> has the structure:<br>CH\u2082OH-CH\u2082-CH\u2082OH<\/li>\n<\/ul>\n\n\n\n<p>Both molecules have the same empirical formula (C\u2083H\u2086O\u2082), but differ in the positioning of the hydroxyl (OH) groups along the carbon chain.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Atomic Masses<\/h3>\n\n\n\n<p>To calculate the molecular mass of propane-1,3-diol, we need to sum the atomic masses of the constituent atoms:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Carbon (C): 12.01 amu<\/li>\n\n\n\n<li>Hydrogen (H): 1.008 amu<\/li>\n\n\n\n<li>Oxygen (O): 16.00 amu<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Step-by-Step Calculation<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Carbon (C)<\/strong>: The molecule has 3 carbon atoms, so the mass contribution from carbon is:<br>3 \u00d7 12.01 = 36.03 amu<\/li>\n\n\n\n<li><strong>Hydrogen (H)<\/strong>: The molecule has 8 hydrogen atoms, so the mass contribution from hydrogen is:<br>6 \u00d7 1.008 = 6.048 amu<\/li>\n\n\n\n<li><strong>Oxygen (O)<\/strong>: The molecule has 2 oxygen atoms, so the mass contribution from oxygen is:<br>2 \u00d7 16.00 = 32.00 amu<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">Total Molecular Mass<\/h3>\n\n\n\n<p>Now, we can add up all the contributions:<br>36.03 amu (C) + 6.048 amu (H) + 32.00 amu (O) = 74.078 amu<\/p>\n\n\n\n<p>Thus, the molecular mass of propane-1,3-diol is approximately <strong>74.1 amu<\/strong>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Explanation<\/h3>\n\n\n\n<p>Both propane-1,2-diol and propane-1,3-diol have the same molecular formula (C\u2083H\u2086O\u2082), so their molecular masses are very similar. The minor difference in the position of the hydroxyl groups does not change the total molecular mass, which is only a few tenths of a unit lower than propane-1,2-diol&#8217;s molecular mass due to the specific arrangement of atoms.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" src=\"https:\/\/learnexams.com\/blog\/wp-content\/uploads\/2025\/07\/learnexams-banner6-695.jpeg\" alt=\"\" class=\"wp-image-257086\"\/><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>The molecular mass of propane-1,2-diol is 76.1 amu . Calculate the molecular mass of propane-1,3-diol, an isomer of propane-1,2-diol. The Correct Answer and Explanation is: The molecular mass of propane-1,2-diol is given as 76.1 amu. Now, we need to calculate the molecular mass of propane-1,3-diol, an isomer of propane-1,2-diol. Molecular Structure Both molecules have the [&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-257082","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/257082","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=257082"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/257082\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=257082"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=257082"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=257082"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}