{"id":7574,"date":"2026-03-05T12:36:28","date_gmt":"2026-03-05T12:36:28","guid":{"rendered":"https:\/\/www.chennaineet.com\/blog\/?p=7574"},"modified":"2026-03-05T12:36:32","modified_gmt":"2026-03-05T12:36:32","slug":"which-of-the-following-is-a-weak-acid","status":"publish","type":"post","link":"https:\/\/www.chennaineet.com\/blog\/which-of-the-following-is-a-weak-acid\/","title":{"rendered":"Which of the Following Is a Weak Acid?"},"content":{"rendered":"\n<p>In chemistry, acids are classified as <strong>strong acids<\/strong> or <strong>weak acids<\/strong> based on how they behave in water. A common question asked in exams is: <strong>\u201cWhich of the following is a weak acid?\u201d<\/strong><\/p>\n\n\n\n<p>To answer this type of question, we must understand how acids <strong>dissociate (break apart) in water<\/strong> and how acid\u2013base reactions work according to scientific theories like the <strong>Bronsted\u2013Lowry theory<\/strong>.<\/p>\n\n\n\n<p>In simple terms, a <strong>strong acid completely dissociates in water<\/strong>, releasing many hydrogen ions (H\u207a), while a <strong>weak acid only partially dissociates<\/strong>. Because of this partial dissociation, weak acids release fewer hydrogen ions into the solution.<\/p>\n\n\n\n<p>Students preparing for chemistry exams can find more solved questions and explanations at <a href=\"https:\/\/chennaineet.com\/\" target=\"_blank\" rel=\"noopener\">chennaineet<\/a>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Question<\/strong><\/h2>\n\n\n\n<p><strong>Which of the following is a weak acid?<\/strong><\/p>\n\n\n\n<p>A. <strong>Acetic acid (CH\u2083COOH)<\/strong><br>B. <strong>Hydrochloric acid (HCl)<\/strong><br>C. <strong>Sulphuric acid (H\u2082SO\u2084)<\/strong><br>D. <strong>Nitric acid (HNO\u2083)<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Bronsted\u2013Lowry Theory of Acids and Bases<\/strong><\/h2>\n\n\n\n<p>To understand weak acids clearly, we first look at the <strong>Bronsted\u2013Lowry theory<\/strong>.<\/p>\n\n\n\n<p>According to this theory:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>A <strong>Bronsted\u2013Lowry acid<\/strong> is a substance that <strong>donates a proton (H\u207a)<\/strong>.<\/li>\n\n\n\n<li>A <strong>Bronsted\u2013Lowry base<\/strong> is a substance that <strong>accepts a proton (H\u207a)<\/strong>.<\/li>\n<\/ul>\n\n\n\n<p>For example, consider the reaction of <strong>acetic acid with water<\/strong>:<\/p>\n\n\n\n<p><strong>CH\u2083COOH + H\u2082O \u21cc H\u2083O\u207a + CH\u2083COO\u207b<\/strong><\/p>\n\n\n\n<p>In this reaction:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Acetic acid (CH\u2083COOH)<\/strong> donates a proton \u2192 acts as an acid<\/li>\n\n\n\n<li><strong>Water (H\u2082O)<\/strong> accepts a proton \u2192 acts as a base<\/li>\n<\/ul>\n\n\n\n<p>This reaction forms a <strong>conjugate acid\u2013base pair<\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Strong Acids vs Weak Acids<\/strong><\/h2>\n\n\n\n<p>Acids are categorized based on how much they <strong>dissociate in water<\/strong>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Strong Acids<\/strong><\/h3>\n\n\n\n<p>Strong acids <strong>completely dissociate in water<\/strong>.<\/p>\n\n\n\n<p>Examples include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Hydrochloric acid (HCl)<\/strong><\/li>\n\n\n\n<li><strong>Sulphuric acid (H\u2082SO\u2084)<\/strong><\/li>\n\n\n\n<li><strong>Nitric acid (HNO\u2083)<\/strong><\/li>\n<\/ul>\n\n\n\n<p>These acids release almost all their hydrogen ions when dissolved in water.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Weak Acids<\/strong><\/h3>\n\n\n\n<p>Weak acids <strong>partially dissociate in water<\/strong>, meaning only some molecules release hydrogen ions.<\/p>\n\n\n\n<p>Example:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Acetic acid (CH\u2083COOH)<\/strong><\/li>\n<\/ul>\n\n\n\n<p>This partial dissociation makes acetic acid a <strong>weak acid<\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Step-by-Step Explanation<\/strong><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Step 1: Examine the options<\/strong><\/h3>\n\n\n\n<p>The given options are:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Acetic acid (CH\u2083COOH)<\/li>\n\n\n\n<li>Hydrochloric acid (HCl)<\/li>\n\n\n\n<li>Sulphuric acid (H\u2082SO\u2084)<\/li>\n\n\n\n<li>Nitric acid (HNO\u2083)<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Step 2: Determine their strength<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>HCl<\/strong> \u2192 Strong acid<\/li>\n\n\n\n<li><strong>H\u2082SO\u2084<\/strong> \u2192 Strong acid<\/li>\n\n\n\n<li><strong>HNO\u2083<\/strong> \u2192 Strong acid<\/li>\n\n\n\n<li><strong>CH\u2083COOH<\/strong> \u2192 Weak acid<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Step 3: Identify the weak acid<\/strong><\/h3>\n\n\n\n<p>Among the given options, <strong>acetic acid does not completely dissociate in water<\/strong>, so it is classified as a <strong>weak acid<\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Final Answer<\/strong><\/h2>\n\n\n\n<p>The correct answer is:<\/p>\n\n\n\n<p><strong>Option A: Acetic acid (CH\u2083COOH)<\/strong><\/p>\n\n\n\n<p>Acetic acid is a <strong>weak acid<\/strong> because it undergoes <strong>partial dissociation in water<\/strong>, unlike strong acids that dissociate completely.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Additional Notes<\/strong><\/h2>\n\n\n\n<p>Acetic acid is commonly found in <strong>vinegar<\/strong>, which is widely used in cooking and food preservation.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Important Facts about Acetic Acid<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Chemical formula: <strong>CH\u2083COOH<\/strong><\/li>\n\n\n\n<li>Weak organic acid<\/li>\n\n\n\n<li>Colourless liquid with a <strong>strong pungent smell<\/strong><\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Uses of Acetic Acid<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Vinegar production<\/li>\n\n\n\n<li>Food preservation<\/li>\n\n\n\n<li>Chemical manufacturing<\/li>\n\n\n\n<li>Laboratory experiments<\/li>\n<\/ul>\n\n\n\n<p>Understanding weak acids like acetic acid helps students learn how <strong>acid\u2013base reactions work in chemistry<\/strong>.<\/p>\n\n\n\n<p>For more chemistry explanations and exam preparation materials, visit <a href=\"https:\/\/chennaineet.com\/\" target=\"_blank\" rel=\"noopener\">chennaineet<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Learn which of the following is a weak acid with MCQ options and a simple explanation of strong and weak acids in chemistry.<\/p>\n","protected":false},"author":2,"featured_media":7575,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[781],"tags":[900,897,895,901,902,898,899,894,896],"class_list":["post-7574","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-question-answer","tag-acetic-acid-dissociation-reaction","tag-acetic-acid-weak-acid-example","tag-bronsted-lowry-acid-definition","tag-chemistry-acid-base-mcq","tag-examples-of-weak-acids","tag-strong-vs-weak-acids-chemistry","tag-weak-acid-chemistry-explanation","tag-weak-acid-mcq-chemistry","tag-which-of-the-following-is-a-weak-acid"],"_links":{"self":[{"href":"https:\/\/www.chennaineet.com\/blog\/wp-json\/wp\/v2\/posts\/7574","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.chennaineet.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.chennaineet.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.chennaineet.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.chennaineet.com\/blog\/wp-json\/wp\/v2\/comments?post=7574"}],"version-history":[{"count":1,"href":"https:\/\/www.chennaineet.com\/blog\/wp-json\/wp\/v2\/posts\/7574\/revisions"}],"predecessor-version":[{"id":7576,"href":"https:\/\/www.chennaineet.com\/blog\/wp-json\/wp\/v2\/posts\/7574\/revisions\/7576"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.chennaineet.com\/blog\/wp-json\/wp\/v2\/media\/7575"}],"wp:attachment":[{"href":"https:\/\/www.chennaineet.com\/blog\/wp-json\/wp\/v2\/media?parent=7574"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.chennaineet.com\/blog\/wp-json\/wp\/v2\/categories?post=7574"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.chennaineet.com\/blog\/wp-json\/wp\/v2\/tags?post=7574"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}