{"id":226,"date":"2025-05-07T10:19:35","date_gmt":"2025-05-07T10:19:35","guid":{"rendered":"https:\/\/yaveni.com\/blog\/?p=226"},"modified":"2025-05-07T10:19:37","modified_gmt":"2025-05-07T10:19:37","slug":"hbr-reacts-fastest-with","status":"publish","type":"post","link":"https:\/\/gaviki.com\/blog\/hbr-reacts-fastest-with\/","title":{"rendered":"HBr reacts fastest with"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">HBr reacts fastest with<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">a. 2-Methyl-1-propanol<br>b. 2-Methyl-2-propanol<br>c. 2-propanol<br>d. 1-propanol<br>e. None of the above<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-cyan-blue-color\"><strong>The correct answer and explanation is :<\/strong><\/mark><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The correct answer is: <strong>b. 2-Methyl-2-propanol<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Explanation (300+ words)<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">The reaction of <strong>HBr (hydrobromic acid)<\/strong> with alcohols is a classic example of a <strong>nucleophilic substitution reaction<\/strong>, where the hydroxyl (-OH) group is replaced by a bromide (Br\u207b) to form an alkyl halide.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The rate of this reaction greatly depends on the <strong>type of alcohol<\/strong>\u2014whether it&#8217;s <strong>primary (1\u00b0)<\/strong>, <strong>secondary (2\u00b0)<\/strong>, or <strong>tertiary (3\u00b0)<\/strong>\u2014and the <strong>mechanism<\/strong> by which the reaction proceeds:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Tertiary alcohols<\/strong> typically undergo <strong>SN1 (unimolecular nucleophilic substitution)<\/strong> mechanisms.<\/li>\n\n\n\n<li><strong>Primary alcohols<\/strong> undergo <strong>SN2 (bimolecular nucleophilic substitution)<\/strong> mechanisms.<\/li>\n\n\n\n<li><strong>Secondary alcohols<\/strong> may undergo either mechanism, depending on the conditions.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">In the <strong>SN1 mechanism<\/strong>, the rate-determining step is the formation of a <strong>carbocation intermediate<\/strong> after the alcohol is protonated and the water molecule leaves. The more <strong>stable<\/strong> the carbocation, the <strong>faster<\/strong> this step occurs.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Let\u2019s analyze the options:<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h4 class=\"wp-block-heading\"><strong>b. 2-Methyl-2-propanol (Tertiary Alcohol)<\/strong><\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li>This is a <strong>tertiary alcohol<\/strong>, with the structure (CH\u2083)\u2083COH.<\/li>\n\n\n\n<li>Upon protonation, it forms a <strong>tertiary carbocation<\/strong>, which is highly <strong>stable<\/strong> due to <strong>inductive effects<\/strong> and <strong>hyperconjugation<\/strong> from the surrounding methyl groups.<\/li>\n\n\n\n<li>The carbocation forms <strong>readily<\/strong>, making the SN1 reaction <strong>very fast<\/strong>.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h4 class=\"wp-block-heading\"><strong>Other Options:<\/strong><\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>a. 2-Methyl-1-propanol<\/strong> \u2013 <strong>Primary alcohol<\/strong>, slower SN2 mechanism.<\/li>\n\n\n\n<li><strong>c. 2-Propanol<\/strong> \u2013 <strong>Secondary alcohol<\/strong>, slower than tertiary alcohol.<\/li>\n\n\n\n<li><strong>d. 1-Propanol<\/strong> \u2013 <strong>Primary alcohol<\/strong>, slowest via SN2.<\/li>\n\n\n\n<li><strong>e. None of the above<\/strong> \u2013 Incorrect, because option <strong>b<\/strong> is a valid and correct choice.<\/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>Conclusion<\/strong><\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">2-Methyl-2-propanol reacts <strong>fastest<\/strong> with HBr because it forms a <strong>tertiary carbocation<\/strong>, which makes the SN1 mechanism highly favorable. The <strong>rate<\/strong> of substitution increases with the <strong>stability<\/strong> of the carbocation intermediate, and tertiary carbocations are the most stable among all. Therefore, <strong>option b<\/strong> is correct.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>HBr reacts fastest with a. 2-Methyl-1-propanolb. 2-Methyl-2-propanolc. 2-propanold. 1-propanole. None of the above The correct answer and explanation is : The correct answer is: b. 2-Methyl-2-propanol Explanation (300+ words) The reaction of HBr (hydrobromic acid) with alcohols is a classic example of a nucleophilic substitution reaction, where the hydroxyl (-OH) group is replaced by a [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[],"tags":[],"class_list":["post-226","post","type-post","status-publish","format-standard","hentry"],"_links":{"self":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/226","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/comments?post=226"}],"version-history":[{"count":1,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/226\/revisions"}],"predecessor-version":[{"id":227,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/226\/revisions\/227"}],"wp:attachment":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/media?parent=226"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/categories?post=226"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/tags?post=226"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}