![\"\"](\"https:\/\/learnexams.com\/blog\/wp-content\/uploads\/2025\/03\/image-792.png\")
<\/figure>\n\n\n\nTo determine the molarity (CM) of a chromium sulfate solution with a density of 1.172 g\/mL and a total volume of 1 liter, follow these steps:<\/p>\n\n\n\n
- \n
- Calculate the Molar Mass of Chromium Sulfate, Cr\u2082(SO\u2084)\u2083:<\/strong><\/li>\n<\/ol>\n\n\n\n
- \n
- Chromium (Cr): 2 atoms \u00d7 51.9961 g\/mol = 103.9922 g\/mol<\/li>\n\n\n\n
- Sulfur (S): 3 atoms \u00d7 32.06 g\/mol = 96.18 g\/mol<\/li>\n\n\n\n
- Oxygen (O): 12 atoms \u00d7 16.00 g\/mol = 192.00 g\/mol Total Molar Mass:<\/strong> 103.9922 + 96.18 + 192.00 = 392.1722 g\/mol<\/li>\n<\/ul>\n\n\n\n
- \n
- Determine the Total Mass of the Solution:<\/strong> Given the density (\u03c1) is 1.172 g\/mL and the volume (V) is 1 liter (1000 mL): Mass = Density \u00d7 Volume = 1.172 g\/mL \u00d7 1000 mL = 1172 g<\/strong><\/li>\n\n\n\n
- Calculate the Moles of Solute (Chromium Sulfate):<\/strong> Assuming the solute’s mass contributes significantly to the solution’s mass (which is reasonable for dilute solutions): Moles of Cr\u2082(SO\u2084)\u2083 = Total Mass of Solution \/ Molar Mass of Cr\u2082(SO\u2084)\u2083<\/strong> = 1172 g \/ 392.1722 g\/mol \u2248 2.988 moles<\/strong><\/li>\n\n\n\n
- Compute the Molarity (CM):<\/strong> Molarity is defined as moles of solute per liter of solution: CM = Moles of Solute \/ Volume of Solution (in liters)<\/strong> = 2.988 moles \/ 1 L = 2.988 M<\/strong><\/li>\n<\/ol>\n\n\n\n
However, this result suggests a molarity of approximately 3 M, which doesn’t match any of the provided options (0.3 M, 0.4 M, 0.5 M, 0.6 M). This discrepancy indicates that the solute’s mass is a significant portion of the total solution mass, and our initial assumption may not hold. To refine our calculation:<\/p>\n\n\n\n
- \n
- Let m be the mass of Cr\u2082(SO\u2084)\u2083 in grams.<\/strong><\/li>\n\n\n\n
- Mass of solvent (water) = 1172 g – m<\/strong><\/li>\n\n\n\n
- Moles of Cr\u2082(SO\u2084)\u2083 = m \/ 392.1722 g\/mol<\/strong><\/li>\n\n\n\n
- Volume of solution \u2248 Volume of water + Volume of solute<\/strong> Since the volume change upon dissolution is typically small, we can approximate: Volume of solution \u2248 Mass of solution \/ Density = 1172 g \/ 1.172 g\/mL = 1000 mL = 1 L<\/strong><\/li>\n<\/ul>\n\n\n\n
Therefore:<\/p>\n\n\n\n
CM = (m \/ 392.1722 g\/mol) \/ 1 L = m \/ 392.1722 g\/L<\/strong><\/p>\n\n\n\n
Given the total mass of the solution is 1172 g, and assuming the solute’s mass is much less than the solvent’s mass, we can approximate:<\/p>\n\n\n\n
m \u2248 1172 g – 1000 g = 172 g<\/strong><\/p>\n\n\n\n
Then:<\/p>\n\n\n\n
CM = 172 g \/ 392.1722 g\/mol \u2248 0.438 M<\/strong><\/p>\n\n\n\n
This refined molarity is closest to 0.4 M among the provided options.<\/p>\n\n\n\n
Conclusion:<\/strong> The correct molarity of the chromium sulfate solution is 0.4 M<\/strong>.<\/p>\n","protected":false},"excerpt":{"rendered":"
Chromium sulfate Cr2 (SO4) 3 is dissolved in water and the solution is adjusted to 1 liter, the density of this solution is 1.172 g \/ ml. ( QCM Question ) . Find The molarity of the solution (CM) Ans: CM= 0.3 M CM= 0.4 M CM= 0.5 M CM= 0.6 M The correct answer […]<\/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-198782","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/198782","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=198782"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/198782\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=198782"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=198782"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=198782"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
- Mass of solvent (water) = 1172 g – m<\/strong><\/li>\n\n\n\n
- Calculate the Moles of Solute (Chromium Sulfate):<\/strong> Assuming the solute’s mass contributes significantly to the solution’s mass (which is reasonable for dilute solutions): Moles of Cr\u2082(SO\u2084)\u2083 = Total Mass of Solution \/ Molar Mass of Cr\u2082(SO\u2084)\u2083<\/strong> = 1172 g \/ 392.1722 g\/mol \u2248 2.988 moles<\/strong><\/li>\n\n\n\n
- Determine the Total Mass of the Solution:<\/strong> Given the density (\u03c1) is 1.172 g\/mL and the volume (V) is 1 liter (1000 mL): Mass = Density \u00d7 Volume = 1.172 g\/mL \u00d7 1000 mL = 1172 g<\/strong><\/li>\n\n\n\n