{"id":200124,"date":"2025-03-13T08:09:59","date_gmt":"2025-03-13T08:09:59","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=200124"},"modified":"2025-03-13T08:10:01","modified_gmt":"2025-03-13T08:10:01","slug":"the-kb-value-for-pyridine-c5h5n-is-1-7x10-9","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/03\/13\/the-kb-value-for-pyridine-c5h5n-is-1-7x10-9\/","title":{"rendered":"The Kb value for pyridine, C5H5N is 1.7\u00d710-9"},"content":{"rendered":"\n<p>The Kb value for pyridine, C5H5N is 1.7\u00d710-9. What is Ka for C5H5NH+<\/p>\n\n\n\n<p><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-6-color\"><strong>The correct answer and explanation is :<\/strong><\/mark><\/p>\n\n\n\n<p>To calculate the ( K_a ) (acid dissociation constant) for ( \\text{C}_5\\text{H}_5\\text{NH}^+ ) (pyridinium ion), we can use the relationship between the ( K_a ) of a conjugate acid and the ( K_b ) of its conjugate base. This relationship is derived from the equation for the ionization of water and the equilibrium expressions for the acid and base dissociation constants.<\/p>\n\n\n\n<p>The general relationship is:<\/p>\n\n\n\n<p>[<br>K_a \\times K_b = K_w<br>]<\/p>\n\n\n\n<p>where:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>( K_a ) is the acid dissociation constant for the conjugate acid (( \\text{C}_5\\text{H}_5\\text{NH}^+ )),<\/li>\n\n\n\n<li>( K_b ) is the base dissociation constant for the conjugate base (pyridine, ( \\text{C}_5\\text{H}_5\\text{N} )),<\/li>\n\n\n\n<li>( K_w ) is the ionization constant for water, which is ( 1.0 \\times 10^{-14} ) at 25\u00b0C.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Step 1: Write the relationship<\/h3>\n\n\n\n<p>Given:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>( K_b ) for pyridine is ( 1.7 \\times 10^{-9} ),<\/li>\n\n\n\n<li>( K_w ) is ( 1.0 \\times 10^{-14} ).<\/li>\n<\/ul>\n\n\n\n<p>We can rearrange the equation to solve for ( K_a ):<\/p>\n\n\n\n<p>[<br>K_a = \\frac{K_w}{K_b}<br>]<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Step 2: Substitute the known values<\/h3>\n\n\n\n<p>[<br>K_a = \\frac{1.0 \\times 10^{-14}}{1.7 \\times 10^{-9}}<br>]<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Step 3: Calculate ( K_a )<\/h3>\n\n\n\n<p>[<br>K_a = 5.88 \\times 10^{-6}<br>]<\/p>\n\n\n\n<p>Thus, the acid dissociation constant ( K_a ) for pyridinium ion ( \\text{C}_5\\text{H}_5\\text{NH}^+ ) is approximately ( 5.88 \\times 10^{-6} ).<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Explanation:<\/h3>\n\n\n\n<p>Pyridine, ( \\text{C}_5\\text{H}_5\\text{N} ), is a weak base that accepts a proton (H+) to form the pyridinium ion, ( \\text{C}_5\\text{H}_5\\text{NH}^+ ). When pyridine accepts a proton, it becomes a conjugate acid. The equilibrium between the base and its conjugate acid is given by the following:<\/p>\n\n\n\n<p>[<br>\\text{C}_5\\text{H}_5\\text{N} + \\text{H}^+ \\rightleftharpoons \\text{C}_5\\text{H}_5\\text{NH}^+<br>]<\/p>\n\n\n\n<p>The base dissociation constant ( K_b ) measures the extent to which pyridine (the base) reacts with water to produce hydroxide ions and pyridinium ions. Conversely, ( K_a ) measures the extent to which the pyridinium ion dissociates to release a proton and form pyridine. Since ( K_b ) and ( K_a ) are related by the water dissociation constant ( K_w ), knowing ( K_b ) allows us to calculate ( K_a ) using the formula above.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The Kb value for pyridine, C5H5N is 1.7\u00d710-9. What is Ka for C5H5NH+ The correct answer and explanation is : To calculate the ( K_a ) (acid dissociation constant) for ( \\text{C}_5\\text{H}_5\\text{NH}^+ ) (pyridinium ion), we can use the relationship between the ( K_a ) of a conjugate acid and the ( K_b ) of [&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-200124","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/200124","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=200124"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/200124\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=200124"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=200124"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=200124"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}