Of the following, which is the best base to create a buffer with a pH = 8.0?<\/p>\n\n\n\n
Aniline, Kb = 4.3 x 10-10<\/p>\n\n\n\n
Ethylamine, Kb = 6.4 x 10-4<\/p>\n\n\n\n
Hydrazine, Kb = 1.3 x 10-6<\/p>\n\n\n\n
Pyridine, Kb = 1.7 x 10-9<\/p>\n\n\n\n
The correct answer and explanation is :<\/strong><\/mark><\/p>\n\n\n\n To create a buffer solution with a pH of 8.0<\/strong>, we need to select a weak base and its conjugate acid pair that has a pKa close to 8.0<\/strong>. The relationship between pKa and Kb for a base is given by:<\/p>\n\n\n\n [ where:<\/p>\n\n\n\n [ For an optimal buffer, the pKa of the conjugate acid should be close to the desired pH (8.0)<\/strong>. Among the given bases, hydrazine has a pKa of 8.11<\/strong>, which is the closest to 8.0.<\/p>\n\n\n\n Hydrazine (Kb = 1.3 \u00d7 10\u207b\u2076) is the best choice<\/strong> because its conjugate acid has a pKa of 8.11<\/strong>, which is ideal for maintaining a buffer at pH = 8.0<\/strong>.<\/p>\n","protected":false},"excerpt":{"rendered":" Of the following, which is the best base to create a buffer with a pH = 8.0? Aniline, Kb = 4.3 x 10-10 Ethylamine, Kb = 6.4 x 10-4 Hydrazine, Kb = 1.3 x 10-6 Pyridine, Kb = 1.7 x 10-9 The correct answer and explanation is : To create a buffer solution with a […]<\/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-202155","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/202155","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=202155"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/202155\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=202155"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=202155"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=202155"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\\text{pKa} = 14 – \\text{pKb}
]<\/p>\n\n\n\n
\\text{pKb} = -\\log Kb
]<\/p>\n\n\n\nStep 1: Calculate pKa for Each Base<\/h3>\n\n\n\n
\n
(\\text{pKb} = -\\log(4.3 \\times 10^{-10}) = 9.37)
(\\text{pKa} = 14 – 9.37 = 4.63)<\/li>\n\n\n\n
(\\text{pKb} = -\\log(6.4 \\times 10^{-4}) = 3.19)
(\\text{pKa} = 14 – 3.19 = 10.81)<\/li>\n\n\n\n
(\\text{pKb} = -\\log(1.3 \\times 10^{-6}) = 5.89)
(\\text{pKa} = 14 – 5.89 = 8.11)<\/li>\n\n\n\n
(\\text{pKb} = -\\log(1.7 \\times 10^{-9}) = 8.77)
(\\text{pKa} = 14 – 8.77 = 5.23)<\/li>\n<\/ol>\n\n\n\nStep 2: Choose the Best Base<\/h3>\n\n\n\n
Conclusion:<\/h3>\n\n\n\n