{"id":190906,"date":"2025-02-14T03:36:39","date_gmt":"2025-02-14T03:36:39","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=190906"},"modified":"2025-02-14T03:36:41","modified_gmt":"2025-02-14T03:36:41","slug":"the-pka-of-acetone-ch3coch3-is-19-3","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/02\/14\/the-pka-of-acetone-ch3coch3-is-19-3\/","title":{"rendered":"The pKa of acetone, CH3COCH3, is 19.3"},"content":{"rendered":"\n<p>The pKa of acetone, CH3COCH3, is 19.3. Which of the following bases is strong enough to de-protonate acetone?<br>(a) KOH (pKa of H2O = 15.7)<br>(b) Na+ \u2013C \u2261 CH (pKa of C2H2 = 25)<br>(c) NaHCO3 (pKa of H2CO3 = 6.4)<br>(d) NaOCH3 (pKa of CH3OH = 15.6)<\/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 determine which base is strong enough to deprotonate acetone (<strong>CH\u2083COCH\u2083<\/strong>, pKa = <strong>19.3<\/strong>), we must compare the pKa values of acetone and the conjugate acids of the bases provided.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Concept: Acid-Base Strength and Deprotonation<\/strong><\/h3>\n\n\n\n<p>A base can deprotonate an acid if the conjugate acid of the base has a <strong>higher<\/strong> pKa than the acid being deprotonated. This is because a larger pKa means the conjugate acid is weaker, making the base stronger.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Analyzing the Bases<\/strong><\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>KOH (pKa of H\u2082O = 15.7)<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>H\u2082O<\/strong> (conjugate acid) has a pKa of <strong>15.7<\/strong>.<\/li>\n\n\n\n<li>Since <strong>15.7 &lt; 19.3<\/strong>, <strong>KOH is too weak<\/strong> to deprotonate acetone.<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Na\u207a \u2013C \u2261 CH (pKa of C\u2082H\u2082 = 25)<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>HC\u2261CH<\/strong> (acetylene, conjugate acid) has a <strong>pKa of 25<\/strong>.<\/li>\n\n\n\n<li>Since <strong>25 > 19.3<\/strong>, <strong>this base is strong enough<\/strong> to deprotonate acetone.<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>NaHCO\u2083 (pKa of H\u2082CO\u2083 = 6.4)<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>H\u2082CO\u2083<\/strong> (carbonic acid, conjugate acid) has a <strong>pKa of 6.4<\/strong>.<\/li>\n\n\n\n<li>Since <strong>6.4 &lt; 19.3<\/strong>, <strong>NaHCO\u2083 is too weak<\/strong> to deprotonate acetone.<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>NaOCH\u2083 (pKa of CH\u2083OH = 15.6)<\/strong><\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>CH\u2083OH<\/strong> (methanol, conjugate acid) has a <strong>pKa of 15.6<\/strong>.<\/li>\n\n\n\n<li>Since <strong>15.6 &lt; 19.3<\/strong>, <strong>NaOCH\u2083 is too weak<\/strong> to deprotonate acetone.<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Conclusion<\/strong><\/h3>\n\n\n\n<p>Only <strong>Na\u207a \u2013C\u2261CH<\/strong> (sodium acetylide) has a conjugate acid (<strong>HC\u2261CH<\/strong>) with a <strong>higher pKa (25) than acetone (19.3)<\/strong>. Thus, it is <strong>strong enough<\/strong> to deprotonate acetone.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Final Answer:<\/strong><\/h3>\n\n\n\n<p><strong>(b) Na\u207a \u2013C \u2261 CH<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"<p>The pKa of acetone, CH3COCH3, is 19.3. Which of the following bases is strong enough to de-protonate acetone?(a) KOH (pKa of H2O = 15.7)(b) Na+ \u2013C \u2261 CH (pKa of C2H2 = 25)(c) NaHCO3 (pKa of H2CO3 = 6.4)(d) NaOCH3 (pKa of CH3OH = 15.6) The Correct Answer and Explanation is : To determine which [&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-190906","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/190906","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=190906"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/190906\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=190906"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=190906"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=190906"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}