{"id":198282,"date":"2025-03-08T15:05:43","date_gmt":"2025-03-08T15:05:43","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=198282"},"modified":"2025-03-08T15:05:46","modified_gmt":"2025-03-08T15:05:46","slug":"the-taste-of-sour-milk-is-lactic-acid","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/03\/08\/the-taste-of-sour-milk-is-lactic-acid\/","title":{"rendered":"The taste of sour milk is lactic acid"},"content":{"rendered":"\n

The taste of sour milk is lactic acid. What is the molecular formula for lactic acid if the percent composition is 40.00% of C, 6.71% of H, 53.29% of O and the approximate molar mass is 90 g\/mol
a. CH2O
b. CHO2
c. C3H6O3
d. CHO
e. C6HO8<\/p>\n\n\n\n

The correct answer and explanation is :<\/strong><\/mark><\/p>\n\n\n\n

Answer: c. C\u2083H\u2086O\u2083<\/strong><\/p>\n\n\n\n

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

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

Lactic acid, responsible for the sour taste in fermented dairy products like sour milk, has the molecular formula C\u2083H\u2086O\u2083. To determine this, we can follow these steps:<\/p>\n\n\n\n

    \n
  1. Calculate the Empirical Formula:<\/strong> Given the percent composition:<\/li>\n<\/ol>\n\n\n\n
      \n
    • Carbon (C):<\/strong> 40.00%<\/li>\n\n\n\n
    • Hydrogen (H):<\/strong> 6.71%<\/li>\n\n\n\n
    • Oxygen (O):<\/strong> 53.29% Assuming a 100 g sample, the masses of each element are:<\/li>\n\n\n\n
    • Carbon:<\/strong> 40.00 g<\/li>\n\n\n\n
    • Hydrogen:<\/strong> 6.71 g<\/li>\n\n\n\n
    • Oxygen:<\/strong> 53.29 g Convert these masses to moles:<\/li>\n\n\n\n
    • Carbon:<\/strong> 40.00 g \/ 12.01 g\/mol \u2248 3.33 mol<\/li>\n\n\n\n
    • Hydrogen:<\/strong> 6.71 g \/ 1.008 g\/mol \u2248 6.66 mol<\/li>\n\n\n\n
    • Oxygen:<\/strong> 53.29 g \/ 16.00 g\/mol \u2248 3.33 mol Determine the simplest whole-number ratio by dividing each by the smallest number of moles (3.33 mol):<\/li>\n\n\n\n
    • Carbon:<\/strong> 3.33 mol \/ 3.33 mol = 1<\/li>\n\n\n\n
    • Hydrogen:<\/strong> 6.66 mol \/ 3.33 mol \u2248 2<\/li>\n\n\n\n
    • Oxygen:<\/strong> 3.33 mol \/ 3.33 mol = 1 This gives the empirical formula CH\u2082O.<\/li>\n<\/ul>\n\n\n\n
        \n
      1. Determine the Molecular Formula:<\/strong> The empirical formula mass is:<\/li>\n<\/ol>\n\n\n\n
          \n
        • C:<\/strong> 12.01 g\/mol<\/li>\n\n\n\n
        • H\u2082:<\/strong> 2.016 g\/mol<\/li>\n\n\n\n
        • O:<\/strong> 16.00 g\/mol\ue206 Total = 12.01 + 2.016 + 16.00 = 30.026 g\/mol Given the approximate molar mass of lactic acid is 90 g\/mol, calculate the ratio: 90 g\/mol \/ 30.026 g\/mol \u2248 3 Multiply the empirical formula by this ratio:<\/li>\n\n\n\n
        • Carbon:<\/strong> C\u2083<\/li>\n\n\n\n
        • Hydrogen:<\/strong> H\u2086<\/li>\n\n\n\n
        • Oxygen:<\/strong> O\u2083 Thus, the molecular formula is C\u2083H\u2086O\u2083.<\/li>\n<\/ul>\n\n\n\n

          Structural Representation:<\/strong><\/p>\n\n\n\n

          The structural formula of lactic acid is:<\/p>\n\n\n\n

             HO-CH\u2082-CH(OH)-COOH<\/code><\/pre>\n\n\n\n
          This structure consists of a three-carbon chain with a hydroxyl group (-OH) and a carboxyl group (-COOH) attached, characteristic of lactic acid.\ue206<\/p>\n","protected":false},"excerpt":{"rendered":"
          The taste of sour milk is lactic acid. What is the molecular formula for lactic acid if the percent composition is 40.00% of C, 6.71% of H, 53.29% of O and the approximate molar mass is 90 g\/mola. CH2Ob. CHO2c. C3H6O3d. CHOe. C6HO8 The correct answer and explanation is : Answer: c. C\u2083H\u2086O\u2083 Explanation: Lactic […]<\/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-198282","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/198282","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=198282"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/198282\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=198282"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=198282"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=198282"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}