Consider the weak acids, HCN and H 2CO 3.
a. Which acid has the larger Ka?
b. Which acid is stronger?
c. Which acid has the stronger conjugate base?
d. Which acid has the weaker conjugate base?
e. When each acid is dissolved in water, for which acid does the equilibrium lie further to the
right?<\/p>\n\n\n\n
The correct answer and explanation is :<\/strong><\/mark><\/p>\n\n\n\n Let’s examine the two weak acids: HCN (hydrocyanic acid)<\/strong> and H\u2082CO\u2083 (carbonic acid)<\/strong>, and answer each question based on their acid dissociation constants (Ka) and the nature of their conjugate bases.<\/p>\n\n\n\n The acid dissociation constant (Ka) measures the strength of an acid in solution. A larger Ka indicates a stronger acid. H\u2082CO\u2083<\/strong> has a larger Ka compared to HCN<\/strong>. This is because carbonic acid is a diprotic acid, meaning it can donate two protons (H\u207a), and its first dissociation step is relatively stronger than the dissociation of HCN. The dissociation of carbonic acid forms bicarbonate (HCO\u2083\u207b), which is a weak base, but it still dissociates more readily than HCN, which has a smaller Ka value.<\/p>\n\n\n\n H\u2082CO\u2083<\/strong> (carbonic acid) is the stronger acid. This is because it dissociates more readily in solution than HCN<\/strong>, as evidenced by its larger Ka value. A stronger acid has a higher Ka, indicating that it more efficiently donates protons to the solution, making H\u2082CO\u2083 a stronger acid than HCN.<\/p>\n\n\n\n The conjugate base of a weak acid is the species that remains after the acid donates a proton. HCN<\/strong> dissociates to form the cyanide ion (CN\u207b), while H\u2082CO\u2083<\/strong> dissociates to form bicarbonate (HCO\u2083\u207b). The conjugate base of HCN<\/strong> (CN\u207b) is stronger because HCN is a weaker acid. In general, the weaker the acid, the stronger its conjugate base, and since HCN is weaker, CN\u207b is a stronger base than HCO\u2083\u207b.<\/p>\n\n\n\n Since H\u2082CO\u2083<\/strong> is the stronger acid, it will have the weaker conjugate base. The conjugate base of H\u2082CO\u2083<\/strong> is HCO\u2083\u207b<\/strong>, which is weaker than CN\u207b<\/strong> because H\u2082CO\u2083<\/strong> dissociates more readily, leaving HCO\u2083\u207b<\/strong> with a lesser tendency to accept a proton.<\/p>\n\n\n\n The equilibrium lies further to the right for H\u2082CO\u2083<\/strong>. This is because H\u2082CO\u2083 has a larger Ka and is a stronger acid, meaning it dissociates more completely in water compared to HCN. As a result, the concentration of dissociated ions (H\u207a and HCO\u2083\u207b) will be higher for carbonic acid at equilibrium, shifting the equilibrium further to the right for H\u2082CO\u2083.<\/p>\n\n\n\n In summary:<\/p>\n\n\n\n Consider the weak acids, HCN and H 2CO 3.a. Which acid has the larger Ka?b. Which acid is stronger?c. Which acid has the stronger conjugate base?d. Which acid has the weaker conjugate base?e. When each acid is dissolved in water, for which acid does the equilibrium lie further to theright? The correct answer and explanation […]<\/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-210795","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/210795","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=210795"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/210795\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=210795"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=210795"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=210795"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}a. Which acid has the larger Ka?<\/strong><\/h3>\n\n\n\n
b. Which acid is stronger?<\/strong><\/h3>\n\n\n\n
c. Which acid has the stronger conjugate base?<\/strong><\/h3>\n\n\n\n
d. Which acid has the weaker conjugate base?<\/strong><\/h3>\n\n\n\n
e. When each acid is dissolved in water, for which acid does the equilibrium lie further to the right?<\/strong><\/h3>\n\n\n\n
\n