Correct answer:<\/strong><\/p>\n\n\n\n The concentration equilibrium expression for the reaction is:<\/p>\n\n\n\n Kc = [HF] \/ [F\u207b]<\/strong><\/p>\n\n\n\n Explanation<\/strong><\/p>\n\n\n\n In chemical equilibrium, the equilibrium constant expression (denoted as Kc<\/strong> when using concentrations) is derived from the balanced chemical equation. It represents the ratio of the concentrations of products to reactants, each raised to the power of their stoichiometric coefficients.<\/p>\n\n\n\n In this case, the reaction is:<\/p>\n\n\n\n F\u207b (aq) + H\u2082O (l) \u21cc HF (aq) + OH\u207b (aq)<\/strong><\/p>\n\n\n\n Note: It seems there was an issue in the question formatting. Since the original question shows HF and water on the right-hand side and “aq” on the left, this is most likely the fluoride ion reacting with water:<\/p>\n\n\n\n F\u207b (aq) + H\u2082O (l) \u21cc HF (aq) + OH\u207b (aq)<\/strong><\/p>\n\n\n\n However, if the reaction given is:<\/p>\n\n\n\n F\u207b (aq) + H\u2082O (l) \u21cc HF (aq) + H\u2082O (l)<\/strong><\/p>\n\n\n\n That would be chemically inconsistent, as water would not appear unchanged on both sides with HF formation. So, we assume the proper form is:<\/p>\n\n\n\n F\u207b (aq) + H\u2082O (l) \u21cc HF (aq) + OH\u207b (aq)<\/strong><\/p>\n\n\n\n This is a heterogeneous equilibrium<\/strong> because water is a pure liquid. In equilibrium expressions, pure solids and pure liquids (like water in liquid form) are not included<\/strong> because their concentrations remain constant throughout the reaction.<\/p>\n\n\n\n Therefore, the equilibrium expression is written as:<\/p>\n\n\n\n Kc = [HF][OH\u207b] \/ [F\u207b]<\/strong><\/p>\n\n\n\n If the original reaction only involved F\u207b and water producing HF, as in:<\/p>\n\n\n\n F\u207b (aq) + H\u2082O (l) \u21cc HF (aq)<\/strong><\/p>\n\n\n\n Then the equilibrium expression would simply be:<\/p>\n\n\n\n Kc = [HF] \/ [F\u207b]<\/strong><\/p>\n\n\n\n This follows the same rule: exclude water since it is a liquid. The square brackets indicate molar concentration. This expression allows chemists to calculate or predict concentrations of species at equilibrium.<\/p>\n\n\n\n KINETICS AND EQUILIBRIUM Writing the concentration equilibrium expression for heterogeneous equilibrium Write the concentration equilibrium constant expression for this reaction (aq) + H2O (aq) \u00e2\u2020\u2019 HF (aq) + H2O (l) The Correct Answer and Explanation is: Correct answer: The concentration equilibrium expression for the reaction is: Kc = [HF] \/ [F\u207b] Explanation In chemical equilibrium, […]<\/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-256816","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/256816","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=256816"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/256816\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=256816"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=256816"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=256816"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"\"](\"https:\/\/learnexams.com\/blog\/wp-content\/uploads\/2025\/07\/learnexams-banner9-179.jpeg\")
<\/figure>\n","protected":false},"excerpt":{"rendered":"