{"id":202843,"date":"2025-03-18T07:41:57","date_gmt":"2025-03-18T07:41:57","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=202843"},"modified":"2025-03-18T07:42:00","modified_gmt":"2025-03-18T07:42:00","slug":"how-many-grams-of-boric-acid-do-you-need-to-prepare-300-ml-of-a-solution-with-a-freezing-point-of-0-64oc","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/03\/18\/how-many-grams-of-boric-acid-do-you-need-to-prepare-300-ml-of-a-solution-with-a-freezing-point-of-0-64oc\/","title":{"rendered":"How many grams of boric acid do you need to prepare 300 mL of a solution with a freezing point of -0.64oC"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">How many grams of boric acid do you need to prepare 300 mL of a solution with a freezing point of -0.64oC. Boric acid has an E value of 0.5.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><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 class=\"wp-block-paragraph\">To determine the grams of boric acid needed, we follow these steps:<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Step 1: Use Freezing Point Depression Formula<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">[<br>\\Delta T_f = i \\cdot K_f \\cdot m<br>]<br>where:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>(\\Delta T_f) = Freezing point depression = (0 &#8211; (-0.64) = 0.64^\\circ C)<\/li>\n\n\n\n<li>(i) = Van\u2019t Hoff factor (for boric acid, it is 1 since it does not ionize significantly)<\/li>\n\n\n\n<li>(K_f) = Cryoscopic constant for water = (1.86^\\circ C \\cdot kg\/mol)<\/li>\n\n\n\n<li>(m) = Molality (moles of solute per kg of solvent)<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Step 2: Solve for Molality<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">[<br>m = \\frac{\\Delta T_f}{i \\cdot K_f} = \\frac{0.64}{1 \\times 1.86} = 0.3441 \\text{ mol\/kg}<br>]<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Step 3: Convert to Moles of Boric Acid<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The molecular weight of boric acid (H\u2083BO\u2083) is 61.83 g\/mol.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">[<br>\\text{Mass} = \\text{Moles} \\times \\text{Molar Mass} = 0.3441 \\times 61.83 = 21.28 \\text{ g} \\text{ per kg of solvent}<br>]<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Step 4: Adjust for Volume<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Since 300 mL (0.3 kg of water) is used:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">[<br>\\text{Mass} = 21.28 \\times 0.3 = 6.38 \\text{ g}<br>]<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Step 5: Adjust for E Value<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Boric acid has an E value of 0.5, meaning its actual effect on freezing point is only half of its weight.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">[<br>\\text{Required Mass} = \\frac{6.38}{0.5} = 12.76 \\text{ g}<br>]<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Final Answer: <strong>12.76 g of boric acid<\/strong> is required.<\/h3>\n","protected":false},"excerpt":{"rendered":"<p>How many grams of boric acid do you need to prepare 300 mL of a solution with a freezing point of -0.64oC. Boric acid has an E value of 0.5. The correct answer and explanation is : To determine the grams of boric acid needed, we follow these steps: Step 1: Use Freezing Point Depression [&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-202843","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/202843","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=202843"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/202843\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=202843"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=202843"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=202843"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}