{"id":194072,"date":"2025-02-22T07:48:22","date_gmt":"2025-02-22T07:48:22","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=194072"},"modified":"2025-02-22T07:48:24","modified_gmt":"2025-02-22T07:48:24","slug":"mercuryii-hydroxide-hgoh2-is-so-insoluble-in-water-that-only-about-2-formula-units-per-billion-dissolve","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/02\/22\/mercuryii-hydroxide-hgoh2-is-so-insoluble-in-water-that-only-about-2-formula-units-per-billion-dissolve\/","title":{"rendered":"Mercury(II) hydroxide, Hg(OH)2, is so insoluble in water that only about 2 formula units per billion dissolve"},"content":{"rendered":"\n

Mercury(II) hydroxide, Hg(OH)2, is so insoluble in water that only about 2 formula units per billion dissolve. It does, however, neutralize hydrochloric acid. Explain, with appropriate net-ionic equations, how the methods in this experiment can be used to obtain the enthalpy of solution for Hg(OH)2 even when direct measurements of that process is not possible.<\/p>\n\n\n\n

The Correct Answer and Explanation is :<\/strong><\/mark><\/p>\n\n\n\n

To determine the enthalpy of solution ((\\Delta H_{\\text{sol}})) of mercury(II) hydroxide ((\\text{Hg(OH)}_2)) indirectly, we can use a thermochemical cycle based on Hess’s Law. Since direct measurement is impractical due to its extremely low solubility, we can utilize its neutralization with hydrochloric acid ((\\text{HCl})) and other measurable reactions.<\/p>\n\n\n\n

Relevant Net Ionic Equations:<\/strong><\/h3>\n\n\n\n
    \n
  1. Dissolution of Mercury(II) Hydroxide (Hypothetical Process)<\/strong>
    [
    \\text{Hg(OH)}2 (s) \\rightleftharpoons \\text{Hg}^{2+} (aq) + 2\\text{OH}^- (aq) ] This process has an unknown enthalpy change ((\\Delta H<\/em>{\\text{sol}})).<\/li>\n\n\n\n
  2. Neutralization of Hydroxide Ions by Hydrochloric Acid<\/strong>
    [
    \\text{OH}^- (aq) + \\text{H}^+ (aq) \\rightarrow \\text{H}2\\text{O} (l) \\quad (\\Delta H<\/em>{\\text{neutralization}})
    ]
    This reaction is well known to have an enthalpy change of approximately (-55.8 \\text{ kJ\/mol}).<\/li>\n\n\n\n
  3. Overall Reaction of Mercury(II) Hydroxide with Hydrochloric Acid<\/strong>
    [
    \\text{Hg(OH)}2 (s) + 2\\text{H}^+ (aq) \\rightarrow \\text{Hg}^{2+} (aq) + 2\\text{H}_2\\text{O} (l) ] The enthalpy change of this reaction ((\\Delta H<\/em>{\\text{rxn}})) can be measured calorimetrically.<\/li>\n<\/ol>\n\n\n\n

    Methodology and Explanation:<\/strong><\/h3>\n\n\n\n
      \n
    • The experiment involves measuring the enthalpy change when a known amount of (\\text{Hg(OH)}_2) is reacted with an excess of hydrochloric acid.<\/li>\n\n\n\n
    • The total heat released ((\\Delta H_{\\text{rxn}})) corresponds to the combination of the dissolution process and the neutralization of hydroxide ions.<\/li>\n\n\n\n
    • Since (\\Delta H_{\\text{neutralization}}) is known, we can use Hess’s Law: [
      \\Delta H_{\\text{sol}} + 2\\Delta H_{\\text{neutralization}} = \\Delta H_{\\text{rxn}}
      ] Solving for (\\Delta H_{\\text{sol}}): [
      \\Delta H_{\\text{sol}} = \\Delta H_{\\text{rxn}} – 2\\Delta H_{\\text{neutralization}}
      ]<\/li>\n\n\n\n
    • This allows us to determine (\\Delta H_{\\text{sol}}) for mercury(II) hydroxide indirectly.<\/li>\n<\/ul>\n\n\n\n

      Conclusion:<\/strong><\/h3>\n\n\n\n

      By using Hess’s Law and calorimetric measurements of the reaction between (\\text{Hg(OH)}_2) and hydrochloric acid, we can bypass direct dissolution measurement and determine the enthalpy of solution accurately.<\/p>\n\n\n\n

      \n\n\n\n

      Now, I’ll generate an image illustrating this thermochemical cycle.<\/p>\n\n\n\n

      I’ve generated an image illustrating the thermochemical cycle for determining the enthalpy of solution ((\\Delta H_{\\text{sol}})) of mercury(II) hydroxide. It includes dissolution, neutralization, and the overall reaction with Hess\u2019s Law application. Let me know if you need any modifications!<\/p>\n\n\n\n

      \"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

      Mercury(II) hydroxide, Hg(OH)2, is so insoluble in water that only about 2 formula units per billion dissolve. It does, however, neutralize hydrochloric acid. Explain, with appropriate net-ionic equations, how the methods in this experiment can be used to obtain the enthalpy of solution for Hg(OH)2 even when direct measurements of that process is not possible. […]<\/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-194072","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/194072","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=194072"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/194072\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=194072"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=194072"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=194072"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}