{"id":209567,"date":"2025-04-29T07:44:37","date_gmt":"2025-04-29T07:44:37","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=209567"},"modified":"2025-04-29T07:44:41","modified_gmt":"2025-04-29T07:44:41","slug":"which-of-the-following-sets-of-empirical-formulas","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/04\/29\/which-of-the-following-sets-of-empirical-formulas\/","title":{"rendered":"Which of the following sets of empirical formulas"},"content":{"rendered":"\n<p>Which of the following sets of empirical formulas, molar masses, and molecular formulas are correct?<\/p>\n\n\n\n<p>a) HO, 34 g\/mol, H2O<br>b) CH4N, 90 g\/mol, C3H12N3<br>c) CaO, 56 g\/mol, Ca2O2<br>d) C3H8O, 120 g\/mol, C3H8O2<br>e) CH, 78 g\/mol, C13H13<\/p>\n\n\n\n<p><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-6-color\"><strong>The correct answer and explanation is :<\/strong><\/mark><\/p>\n\n\n\n<h3 class=\"wp-block-heading\">a) HO, 34 g\/mol, H2O<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Empirical formula<\/strong>: HO (represents one hydrogen atom and one oxygen atom).<\/li>\n\n\n\n<li><strong>Molar mass of HO<\/strong>: The atomic mass of hydrogen is approximately 1 g\/mol, and that of oxygen is approximately 16 g\/mol. Thus, the molar mass of HO is (1 + 16 = 17 \\, \\text{g\/mol}).<\/li>\n\n\n\n<li><strong>Molecular formula<\/strong>: H2O (this is water, so the molecular formula is correct).<\/li>\n\n\n\n<li><strong>Issue<\/strong>: The molar mass of HO is 17 g\/mol, but it is given as 34 g\/mol, which doesn&#8217;t match. Therefore, this set is <strong>incorrect<\/strong>.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">b) CH4N, 90 g\/mol, C3H12N3<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Empirical formula<\/strong>: CH4N (represents 1 carbon, 4 hydrogens, and 1 nitrogen).<\/li>\n\n\n\n<li><strong>Molar mass of CH4N<\/strong>: Carbon (12 g\/mol), hydrogen (1 g\/mol, 4 hydrogens), nitrogen (14 g\/mol), so the molar mass is (12 + 4 + 14 = 30 \\, \\text{g\/mol}).<\/li>\n\n\n\n<li><strong>Molecular formula<\/strong>: C3H12N3 (this suggests 3 carbons, 12 hydrogens, and 3 nitrogen atoms).<\/li>\n\n\n\n<li><strong>Issue<\/strong>: The molar mass of the empirical formula CH4N is 30 g\/mol, but it is given as 90 g\/mol, which is much higher. This is not consistent with the molecular formula C3H12N3. Therefore, this set is <strong>incorrect<\/strong>.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">c) CaO, 56 g\/mol, Ca2O2<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Empirical formula<\/strong>: CaO (represents 1 calcium and 1 oxygen).<\/li>\n\n\n\n<li><strong>Molar mass of CaO<\/strong>: The atomic mass of calcium is 40 g\/mol, and that of oxygen is 16 g\/mol. Thus, the molar mass of CaO is (40 + 16 = 56 \\, \\text{g\/mol}).<\/li>\n\n\n\n<li><strong>Molecular formula<\/strong>: Ca2O2 (this simplifies to CaO, as 2 calcium atoms and 2 oxygen atoms form the same empirical formula).<\/li>\n\n\n\n<li><strong>Issue<\/strong>: The empirical formula and molar mass are correct, and the molecular formula is just a multiple of the empirical formula. Therefore, this set is <strong>correct<\/strong>.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">d) C3H8O, 120 g\/mol, C3H8O2<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Empirical formula<\/strong>: C3H8O (represents 3 carbons, 8 hydrogens, and 1 oxygen).<\/li>\n\n\n\n<li><strong>Molar mass of C3H8O<\/strong>: The atomic mass of carbon is 12 g\/mol, hydrogen is 1 g\/mol, and oxygen is 16 g\/mol. Thus, the molar mass is (3 \\times 12 + 8 \\times 1 + 16 = 36 + 8 + 16 = 60 \\, \\text{g\/mol}).<\/li>\n\n\n\n<li><strong>Molecular formula<\/strong>: C3H8O2 (this suggests 3 carbons, 8 hydrogens, and 2 oxygens).<\/li>\n\n\n\n<li><strong>Issue<\/strong>: The molar mass of C3H8O is 60 g\/mol, but it is given as 120 g\/mol, which is inconsistent with the molecular formula C3H8O2. Therefore, this set is <strong>incorrect<\/strong>.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">e) CH, 78 g\/mol, C13H13<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Empirical formula<\/strong>: CH (represents 1 carbon and 1 hydrogen).<\/li>\n\n\n\n<li><strong>Molar mass of CH<\/strong>: The atomic mass of carbon is 12 g\/mol, and hydrogen is 1 g\/mol. Thus, the molar mass of CH is (12 + 1 = 13 \\, \\text{g\/mol}).<\/li>\n\n\n\n<li><strong>Molecular formula<\/strong>: C13H13 (this suggests 13 carbons and 13 hydrogens).<\/li>\n\n\n\n<li><strong>Issue<\/strong>: The molar mass of CH is 13 g\/mol, but the molecular formula C13H13 corresponds to a molar mass of (13 \\times 12 + 13 \\times 1 = 156 + 13 = 169 \\, \\text{g\/mol}). Given that the molar mass is 78 g\/mol, this set is <strong>incorrect<\/strong>.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Final Answer:<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Correct<\/strong>: c) CaO, 56 g\/mol, Ca2O2<\/li>\n\n\n\n<li><strong>Incorrect<\/strong>: a), b), d), e)<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Explanation:<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Empirical formulas represent the simplest whole number ratio of elements in a compound.<\/li>\n\n\n\n<li>The molar mass of the empirical formula should match the given molar mass, and the molecular formula is often a multiple of the empirical formula.<\/li>\n\n\n\n<li>When the empirical formula, molar mass, and molecular formula are not consistent, the set is incorrect. Only option c) satisfies all conditions.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Which of the following sets of empirical formulas, molar masses, and molecular formulas are correct? a) HO, 34 g\/mol, H2Ob) CH4N, 90 g\/mol, C3H12N3c) CaO, 56 g\/mol, Ca2O2d) C3H8O, 120 g\/mol, C3H8O2e) CH, 78 g\/mol, C13H13 The correct answer and explanation is : a) HO, 34 g\/mol, H2O b) CH4N, 90 g\/mol, C3H12N3 c) CaO, [&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-209567","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/209567","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=209567"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/209567\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=209567"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=209567"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=209567"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}