{"id":197870,"date":"2025-03-07T18:50:14","date_gmt":"2025-03-07T18:50:14","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=197870"},"modified":"2025-03-07T18:50:17","modified_gmt":"2025-03-07T18:50:17","slug":"how-much-of-the-primary-standard-benzoic-acid-fm-122-12-density-5-1-27-g-ml-should-you-weigh-out-to-obtain-a-100-0-mm-aqueous-solution-in-a-volume-of-250-ml","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/03\/07\/how-much-of-the-primary-standard-benzoic-acid-fm-122-12-density-5-1-27-g-ml-should-you-weigh-out-to-obtain-a-100-0-mm-aqueous-solution-in-a-volume-of-250-ml\/","title":{"rendered":"How much of the primary standard benzoic acid (FM 122.12, density 5 1.27 g\/mL) should you weigh out to obtain a 100.0 mM aqueous solution in a volume of 250 mL"},"content":{"rendered":"\n<p>a) How much of the primary standard benzoic acid (FM 122.12, density 5 1.27 g\/mL) should you weigh out to obtain a 100.0 mM aqueous solution in a volume of 250 mL?<\/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<p>To calculate how much benzoic acid you need to weigh out to obtain a 100.0 mM aqueous solution in a volume of 250 mL, we need to follow these steps:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Step 1: Understand the Problem<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>The desired concentration of the solution is 100.0 mM (millimolar), which is 0.1000 moles per liter (since 1 mM = 0.001 mol\/L).<\/li>\n\n\n\n<li>The volume of the solution is 250 mL (0.250 L).<\/li>\n\n\n\n<li>Benzoic acid has a molecular formula of <strong>C\u2086H\u2085COOH<\/strong>, with a molecular mass of 122.12 g\/mol.<\/li>\n\n\n\n<li>The density of benzoic acid is 1.27 g\/mL.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Step 2: Calculate the Moles Required<\/h3>\n\n\n\n<p>To find out how many moles of benzoic acid we need for a 100.0 mM solution in 250 mL, we use the formula for molarity:<\/p>\n\n\n\n<p>[<br>\\text{Moles of solute} = \\text{Molarity} \\times \\text{Volume}<br>]<\/p>\n\n\n\n<p>Substituting the values:<\/p>\n\n\n\n<p>[<br>\\text{Moles of benzoic acid} = 0.1000 \\, \\text{mol\/L} \\times 0.250 \\, \\text{L} = 0.0250 \\, \\text{mol}<br>]<\/p>\n\n\n\n<p>So, we need <strong>0.0250 moles<\/strong> of benzoic acid.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Step 3: Convert Moles to Mass<\/h3>\n\n\n\n<p>Now, we need to convert moles of benzoic acid to grams using the molecular weight of benzoic acid, which is 122.12 g\/mol:<\/p>\n\n\n\n<p>[<br>\\text{Mass of benzoic acid} = \\text{Moles} \\times \\text{Molar Mass}<br>]<\/p>\n\n\n\n<p>[<br>\\text{Mass of benzoic acid} = 0.0250 \\, \\text{mol} \\times 122.12 \\, \\text{g\/mol} = 3.053 \\, \\text{g}<br>]<\/p>\n\n\n\n<p>So, you need to weigh out <strong>3.053 g<\/strong> of benzoic acid.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Step 4: Verification Using Density<\/h3>\n\n\n\n<p>We can also verify this by using the density of benzoic acid (1.27 g\/mL). To calculate how much volume corresponds to the mass of benzoic acid, we can use the formula:<\/p>\n\n\n\n<p>[<br>\\text{Volume of benzoic acid} = \\frac{\\text{Mass}}{\\text{Density}}<br>]<\/p>\n\n\n\n<p>[<br>\\text{Volume of benzoic acid} = \\frac{3.053 \\, \\text{g}}{1.27 \\, \\text{g\/mL}} = 2.4 \\, \\text{mL}<br>]<\/p>\n\n\n\n<p>Thus, 3.053 g of benzoic acid corresponds to 2.4 mL of liquid benzoic acid.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Final Answer:<\/h3>\n\n\n\n<p>We need to weigh out <strong>3.053 g<\/strong> of benzoic acid to prepare 250 mL of a 100.0 mM aqueous solution.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>a) How much of the primary standard benzoic acid (FM 122.12, density 5 1.27 g\/mL) should you weigh out to obtain a 100.0 mM aqueous solution in a volume of 250 mL? The correct answer and explanation is : To calculate how much benzoic acid you need to weigh out to obtain a 100.0 mM [&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-197870","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/197870","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=197870"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/197870\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=197870"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=197870"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=197870"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}