{"id":212739,"date":"2025-05-08T08:33:21","date_gmt":"2025-05-08T08:33:21","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=212739"},"modified":"2025-05-08T08:33:24","modified_gmt":"2025-05-08T08:33:24","slug":"the-compound-leadii-chromate-pbcro4-molar-mass-323-194-g-mol-is-only-slightly-soluble-in-water","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/05\/08\/the-compound-leadii-chromate-pbcro4-molar-mass-323-194-g-mol-is-only-slightly-soluble-in-water\/","title":{"rendered":"The compound lead(II) chromate (PbCrO4, molar mass = 323.194 g\/mol) is only slightly soluble in water."},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">The compound lead(II) chromate (PbCrO4, molar mass = 323.194 g\/mol) is only slightly soluble in water. Its Ksp at 25\u00b0C is 1.8\u00d710-14. Estimate the solubility of lead(II) chromate in water in units of grams per 100 mL of water. g per 100 mL<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-0-color\">The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">To estimate the solubility of lead(II) chromate (PbCrO\u2084) in water in <strong>grams per 100 mL<\/strong>, we first determine its <strong>solubility in mol\/L (molar solubility)<\/strong> using its <strong>Ksp<\/strong> value, then convert that to grams per 100 mL.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Step 1: Dissociation Equation<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Lead(II) chromate dissociates in water as: PbCrO4(s)\u21ccPb2+(aq)+CrO42\u2212(aq)\\text{PbCrO}_4 (s) \\rightleftharpoons \\text{Pb}^{2+} (aq) + \\text{CrO}_4^{2-} (aq)PbCrO4\u200b(s)\u21ccPb2+(aq)+CrO42\u2212\u200b(aq)<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Let the solubility be <strong>s mol\/L<\/strong>, then:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>[Pb2+]=s[Pb^{2+}] = s[Pb2+]=s<\/li>\n\n\n\n<li>[CrO42\u2212]=s[CrO_4^{2-}] = s[CrO42\u2212\u200b]=s<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Step 2: Ksp Expression<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Ksp=[Pb2+][CrO42\u2212]=s\u22c5s=s2K_{sp} = [\\text{Pb}^{2+}][\\text{CrO}_4^{2-}] = s \\cdot s = s^2Ksp\u200b=[Pb2+][CrO42\u2212\u200b]=s\u22c5s=s2 1.8\u00d710\u221214=s21.8 \\times 10^{-14} = s^21.8\u00d710\u221214=s2 s=1.8\u00d710\u221214=1.34\u00d710\u22127&nbsp;mol\/Ls = \\sqrt{1.8 \\times 10^{-14}} = 1.34 \\times 10^{-7} \\text{ mol\/L}s=1.8\u00d710\u221214\u200b=1.34\u00d710\u22127&nbsp;mol\/L<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Step 3: Convert molar solubility to grams per liter<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Molar&nbsp;mass&nbsp;of&nbsp;PbCrO4=323.194&nbsp;g\/mol\\text{Molar mass of PbCrO}_4 = 323.194 \\text{ g\/mol}Molar&nbsp;mass&nbsp;of&nbsp;PbCrO4\u200b=323.194&nbsp;g\/mol Solubility&nbsp;(g\/L)=1.34\u00d710\u22127&nbsp;mol\/L\u00d7323.194&nbsp;g\/mol\u22484.33\u00d710\u22125&nbsp;g\/L\\text{Solubility (g\/L)} = 1.34 \\times 10^{-7} \\text{ mol\/L} \\times 323.194 \\text{ g\/mol} \\approx 4.33 \\times 10^{-5} \\text{ g\/L}Solubility&nbsp;(g\/L)=1.34\u00d710\u22127&nbsp;mol\/L\u00d7323.194&nbsp;g\/mol\u22484.33\u00d710\u22125&nbsp;g\/L<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Step 4: Convert g\/L to g per 100 mL<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Solubility&nbsp;(g\/100&nbsp;mL)=4.33\u00d710\u22125&nbsp;g1000&nbsp;mL\u00d7100&nbsp;mL=4.33\u00d710\u22126&nbsp;g\/100&nbsp;mL\\text{Solubility (g\/100 mL)} = \\frac{4.33 \\times 10^{-5} \\text{ g}}{1000 \\text{ mL}} \\times 100 \\text{ mL} = 4.33 \\times 10^{-6} \\text{ g\/100 mL}Solubility&nbsp;(g\/100&nbsp;mL)=1000&nbsp;mL4.33\u00d710\u22125&nbsp;g\u200b\u00d7100&nbsp;mL=4.33\u00d710\u22126&nbsp;g\/100&nbsp;mL<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 Final Answer:<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">4.33\u00d710\u22126&nbsp;g&nbsp;per&nbsp;100&nbsp;mL\\boxed{4.33 \\times 10^{-6} \\text{ g per 100 mL}}4.33\u00d710\u22126&nbsp;g&nbsp;per&nbsp;100&nbsp;mL\u200b<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\ud83e\uddea Explanation (300+ words):<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">Solubility is a measure of how much of a substance can dissolve in a given amount of solvent. For sparingly soluble salts like lead(II) chromate (PbCrO\u2084), solubility is often calculated using the solubility product constant (Ksp). The Ksp is an equilibrium constant that reflects the extent to which a salt dissociates into its ions in solution.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When PbCrO\u2084 dissolves, it breaks into Pb\u00b2\u207a and CrO\u2084\u00b2\u207b ions in a 1:1 molar ratio. If we let \u201cs\u201d represent the molar solubility (in mol\/L), then the equilibrium concentrations of both Pb\u00b2\u207a and CrO\u2084\u00b2\u207b will be \u201cs.\u201d The Ksp expression for this equilibrium is then Ksp=[Pb2+][CrO42\u2212]=s2K_{sp} = [Pb^{2+}][CrO_4^{2-}] = s^2Ksp\u200b=[Pb2+][CrO42\u2212\u200b]=s2. By substituting the known Ksp value of 1.8\u00d710\u2212141.8 \\times 10^{-14}1.8\u00d710\u221214, we can solve for \u201cs,\u201d the molar solubility.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Once the molar solubility is determined (approximately 1.34\u00d710\u221271.34 \\times 10^{-7}1.34\u00d710\u22127 mol\/L), we convert it to mass by multiplying it by the molar mass of PbCrO\u2084 (323.194 g\/mol), resulting in about 4.33\u00d710\u221254.33 \\times 10^{-5}4.33\u00d710\u22125 g\/L. Since the question asks for grams per 100 mL, we scale this down by a factor of 10 (because 100 mL is one-tenth of a liter), yielding 4.33\u00d710\u221264.33 \\times 10^{-6}4.33\u00d710\u22126 g per 100 mL.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This very low solubility reflects the fact that PbCrO\u2084 is highly insoluble in water\u2014a property common among heavy metal chromates. Such data is important in environmental chemistry, where understanding the mobility and bioavailability of heavy metal compounds is critical for pollution control and water safety.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The compound lead(II) chromate (PbCrO4, molar mass = 323.194 g\/mol) is only slightly soluble in water. Its Ksp at 25\u00b0C is 1.8\u00d710-14. Estimate the solubility of lead(II) chromate in water in units of grams per 100 mL of water. g per 100 mL The Correct Answer and Explanation is: To estimate the solubility of lead(II) [&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-212739","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/212739","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=212739"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/212739\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=212739"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=212739"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=212739"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}