{"id":219472,"date":"2025-05-26T08:11:03","date_gmt":"2025-05-26T08:11:03","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=219472"},"modified":"2025-05-26T08:11:05","modified_gmt":"2025-05-26T08:11:05","slug":"calculate-the-ph-of-the-solution-after-the-addition-of-10-0-ml-of-naoh-solution","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/05\/26\/calculate-the-ph-of-the-solution-after-the-addition-of-10-0-ml-of-naoh-solution\/","title":{"rendered":"Calculate the pH of the solution after the addition of 10.0 ml of NaOH solution."},"content":{"rendered":"\n<p>20.0 ml of 0.200M hypobromous acid, HBrO, is titrated with 0.250M sodium hydroxide, NaOH. Calculate the pH of the solution after the addition of 10.0 ml of NaOH solution.<\/p>\n\n\n\n<p>Then Determine<\/p>\n\n\n\n<p>25.0 ml of 0.600M hypobromous acid, HBrO, is titrated with 0.400M sodium hydroxide, NaOH. Calculate the pH of the solution at the equivalence point of the titration.<\/p>\n\n\n\n<p>Hypobromous acid Ka=2.3E-9<\/p>\n\n\n\n<p>\u00c3\u201a\u00c2<\/p>\n\n\n\n<p><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-1-color\">The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Answer Summary<\/strong><\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>After adding 10.0 mL of NaOH to 20.0 mL of 0.200 M HBrO<\/strong>,<br><strong>pH \u2248 8.66<\/strong><\/li>\n\n\n\n<li><strong>At the equivalence point of titrating 25.0 mL of 0.600 M HBrO with 0.400 M NaOH<\/strong>,<br><strong>pH \u2248 10.34<\/strong><\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Detailed Explanation<\/strong><\/h3>\n\n\n\n<p>Hypobromous acid (HBrO) is a <strong>weak acid<\/strong>, and NaOH is a <strong>strong base<\/strong>. In acid-base titrations involving a weak acid and a strong base, the pH depends on the stage of the titration.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h4 class=\"wp-block-heading\"><strong>1. After Adding 10.0 mL of NaOH to 20.0 mL of 0.200 M HBrO<\/strong><\/h4>\n\n\n\n<p><strong>Step 1: Moles of Reactants<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Moles of HBrO = 0.0200 L \u00d7 0.200 mol\/L = 0.00400 mol<\/li>\n\n\n\n<li>Moles of NaOH = 0.0100 L \u00d7 0.250 mol\/L = 0.00250 mol<\/li>\n<\/ul>\n\n\n\n<p><strong>Step 2: Reaction<\/strong><br>HBrO+OH\u2212\u2192BrO\u2212+H2O\\text{HBrO} + \\text{OH}^- \\rightarrow \\text{BrO}^- + H_2O<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>NaOH reacts with HBrO to form BrO\u207b.<\/li>\n\n\n\n<li>Moles of HBrO remaining = 0.00400 \u2013 0.00250 = 0.00150 mol<\/li>\n\n\n\n<li>Moles of BrO\u207b formed = 0.00250 mol<\/li>\n\n\n\n<li>Total volume = 20.0 + 10.0 = 30.0 mL = 0.0300 L<\/li>\n<\/ul>\n\n\n\n<p><strong>Step 3: Use Henderson-Hasselbalch Equation<\/strong> pKa=\u2212log\u2061(2.3\u00d710\u22129)\u22488.64\\text{pKa} = -\\log(2.3 \\times 10^{-9}) \u2248 8.64 pH=pKa+log\u2061([BrO\u2212][HBrO])=8.64+log\u2061(0.002500.00150)=8.64+log\u2061(1.6667)\u22488.64+0.22=8.66\\text{pH} = pKa + \\log\\left( \\frac{[\\text{BrO}^-]}{[\\text{HBrO}]} \\right) = 8.64 + \\log\\left( \\frac{0.00250}{0.00150} \\right) = 8.64 + \\log(1.6667) \u2248 8.64 + 0.22 = \\boxed{8.66}<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h4 class=\"wp-block-heading\"><strong>2. At the Equivalence Point of Titrating 25.0 mL of 0.600 M HBrO with 0.400 M NaOH<\/strong><\/h4>\n\n\n\n<p><strong>Step 1: Moles of HBrO =<\/strong> 0.025 L \u00d7 0.600 mol\/L = 0.0150 mol<br>Since NaOH is in stoichiometric proportion, 0.0150 mol is required.<\/p>\n\n\n\n<p><strong>Volume of NaOH needed:<\/strong> V=0.0150&nbsp;mol0.400&nbsp;mol\/L=0.0375&nbsp;L=37.5&nbsp;mLV = \\frac{0.0150\\ \\text{mol}}{0.400\\ \\text{mol\/L}} = 0.0375\\ \\text{L} = 37.5\\ \\text{mL}<\/p>\n\n\n\n<p>Total volume = 25.0 + 37.5 = 62.5 mL = 0.0625 L<\/p>\n\n\n\n<p>At equivalence, all HBrO is converted to BrO\u207b (a weak base).<\/p>\n\n\n\n<p><strong>[BrO\u207b] =<\/strong> 0.0150 mol \/ 0.0625 L = 0.240 M<\/p>\n\n\n\n<p>Now calculate pH using base hydrolysis: Kb=KwKa=1.0\u00d710\u2212142.3\u00d710\u22129=4.35\u00d710\u22126\\text{Kb} = \\frac{K_w}{K_a} = \\frac{1.0 \\times 10^{-14}}{2.3 \\times 10^{-9}} = 4.35 \\times 10^{-6} [OH\u2212]=Kb\u00d7[BrO\u2212]=4.35\u00d710\u22126\u00d70.240\u22481.044\u00d710\u22126\u22481.02\u00d710\u22123[OH^-] = \\sqrt{Kb \\times [BrO^-]} = \\sqrt{4.35 \\times 10^{-6} \\times 0.240} \u2248 \\sqrt{1.044 \\times 10^{-6}} \u2248 1.02 \\times 10^{-3} pOH=\u2212log\u2061(1.02\u00d710\u22123)\u22482.99\u21d2pH=14\u22122.99=10.34\\text{pOH} = -\\log(1.02 \\times 10^{-3}) \u2248 2.99 \\quad \\Rightarrow \\quad \\text{pH} = 14 &#8211; 2.99 = \\boxed{10.34}<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u2705 Final Answers:<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>pH after 10.0 mL NaOH added<\/strong>: <strong>8.66<\/strong><\/li>\n\n\n\n<li><strong>pH at equivalence point<\/strong>: <strong>10.34<\/strong><\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image size-full\"><img decoding=\"async\" src=\"https:\/\/learnexams.com\/blog\/wp-content\/uploads\/2025\/05\/learnexams-banner8-16.jpeg\" alt=\"\" class=\"wp-image-219473\"\/><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>20.0 ml of 0.200M hypobromous acid, HBrO, is titrated with 0.250M sodium hydroxide, NaOH. Calculate the pH of the solution after the addition of 10.0 ml of NaOH solution. Then Determine 25.0 ml of 0.600M hypobromous acid, HBrO, is titrated with 0.400M sodium hydroxide, NaOH. Calculate the pH of the solution at the equivalence point [&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-219472","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/219472","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=219472"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/219472\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=219472"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=219472"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=219472"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}