{"id":257001,"date":"2025-07-16T15:21:59","date_gmt":"2025-07-16T15:21:59","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=257001"},"modified":"2025-07-16T15:22:01","modified_gmt":"2025-07-16T15:22:01","slug":"the-molecular-mass-of-propane-12-diol-is-76-1-amu","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/07\/16\/the-molecular-mass-of-propane-12-diol-is-76-1-amu\/","title":{"rendered":"The molecular mass of propane-1,2-diol is 76.1 amu"},"content":{"rendered":"\n

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

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

Correct Answer:<\/strong>
The molecular mass of propane-1,3-diol<\/strong> is 76.1 amu<\/strong>.<\/p>\n\n\n\n

\n\n\n\n

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

Propane-1,3-diol and propane-1,2-diol are isomers<\/strong>, meaning they have the same molecular formula<\/strong> but different arrangements of atoms. Since molecular mass depends only on the types and numbers of atoms in a molecule, isomers always have identical molecular masses<\/strong>.<\/p>\n\n\n\n

Let\u2019s verify this by calculating the molecular formula and then computing the molecular mass step by step.<\/p>\n\n\n\n

Step 1: Determine the molecular formula of propane-1,3-diol<\/h3>\n\n\n\n

Both propane-1,2-diol and propane-1,3-diol have the molecular formula:<\/p>\n\n\n\n

C\u2083H\u2088O\u2082<\/strong><\/p>\n\n\n\n

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

    \n
  • “Propane” means a chain of 3 carbon atoms.<\/li>\n\n\n\n
  • “Diol” means there are two hydroxyl (OH) groups.<\/li>\n\n\n\n
  • The numbers 1,2 and 1,3 just tell us where<\/strong> the OH groups are located on the carbon chain, not how many atoms are present.<\/li>\n<\/ul>\n\n\n\n

    So, the atom counts are:<\/p>\n\n\n\n

      \n
    • Carbon (C) = 3<\/li>\n\n\n\n
    • Hydrogen (H) = 8<\/li>\n\n\n\n
    • Oxygen (O) = 2<\/li>\n<\/ul>\n\n\n\n

      Step 2: Calculate the molecular mass<\/h3>\n\n\n\n

      Now we add up the atomic masses of each atom:<\/p>\n\n\n\n

        \n
      • Carbon: 3 \u00d7 12.01 = 36.03 amu<\/li>\n\n\n\n
      • Hydrogen: 8 \u00d7 1.008 = 8.064 amu<\/li>\n\n\n\n
      • Oxygen: 2 \u00d7 16.00 = 32.00 amu<\/li>\n<\/ul>\n\n\n\n

        Total molecular mass:
        36.03 + 8.064 + 32.00 = 76.094 amu<\/strong>, which rounds to 76.1 amu<\/strong><\/p>\n\n\n\n

        Final Point:<\/h3>\n\n\n\n

        Since propane-1,2-diol and propane-1,3-diol are structural isomers with the same molecular formula, their molecular masses must be equal<\/strong>.<\/p>\n\n\n\n

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

        Thus, the molecular mass of propane-1,3-diol<\/strong> is 76.1 amu<\/strong>.<\/p>\n\n\n\n

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

        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: Correct Answer:The molecular mass of propane-1,3-diol is 76.1 amu. Explanation: Propane-1,3-diol and propane-1,2-diol are isomers, meaning they have the same molecular formula but different arrangements of atoms. Since molecular mass […]<\/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-257001","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/257001","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=257001"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/257001\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=257001"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=257001"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=257001"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}