{"id":3203,"date":"2025-06-14T20:01:58","date_gmt":"2025-06-14T20:01:58","guid":{"rendered":"https:\/\/yaveni.com\/blog\/?p=3203"},"modified":"2025-06-14T20:02:00","modified_gmt":"2025-06-14T20:02:00","slug":"nitration-of-1-4-dimethylbenzene-p-xylene-gives-a-single-product-having-the-molecular-formula-c8h9no2-in-high-yield-2","status":"publish","type":"post","link":"https:\/\/gaviki.com\/blog\/nitration-of-1-4-dimethylbenzene-p-xylene-gives-a-single-product-having-the-molecular-formula-c8h9no2-in-high-yield-2\/","title":{"rendered":"Nitration of 1, 4-dimethylbenzene (p-xylene) gives a single product having the molecular formula C8H9NO2 in high yield"},"content":{"rendered":"\n<p>Nitration of 1, 4-dimethylbenzene (p-xylene) gives a single product having the molecular formula C8H9NO2 in high yield. What is this product?<\/p>\n\n\n\n<p><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>The nitration of <strong>1,4-dimethylbenzene (p-xylene)<\/strong> gives <strong>2-nitro-1,4-dimethylbenzene<\/strong> as the major product. Its molecular formula is <strong>C\u2088H\u2089NO\u2082<\/strong>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Explanation (300 words):<\/h3>\n\n\n\n<p><strong>p-Xylene<\/strong> is a benzene ring substituted with two methyl groups at the <strong>1 and 4 positions<\/strong>. Methyl groups are <strong>electron-donating<\/strong> via hyperconjugation and inductive effects, which means they activate the aromatic ring toward electrophilic substitution and direct incoming electrophiles to the <strong>ortho and para positions<\/strong> relative to themselves.<\/p>\n\n\n\n<p>During <strong>nitration<\/strong>, the reaction mixture typically involves <strong>concentrated nitric acid (HNO\u2083)<\/strong> and <strong>concentrated sulfuric acid (H\u2082SO\u2084)<\/strong>. The nitronium ion (<strong>NO\u2082\u207a<\/strong>), generated in situ, acts as the <strong>electrophile<\/strong>, attacking the aromatic ring.<\/p>\n\n\n\n<p>Given that both methyl groups are already in para positions relative to each other (1,4), each methyl group directs the incoming nitro group to positions <strong>ortho and para<\/strong> relative to itself. However, due to the symmetry of the p-xylene molecule, there is only <strong>one unique position<\/strong> (position 2 or 6) that is <strong>ortho to one methyl group and meta to the other<\/strong>, making the nitro substitution selective.<\/p>\n\n\n\n<p>Therefore, the nitration occurs at either position 2 or 6 \u2014 both are equivalent due to symmetry \u2014 resulting in a <strong>single mononitrated product<\/strong>:<br><strong>2-nitro-1,4-dimethylbenzene<\/strong> (also called <strong>2-nitro-p-xylene<\/strong>).<\/p>\n\n\n\n<p>This product is favored both electronically and sterically:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Electronically<\/strong>, both methyl groups enhance the reactivity of the ring.<\/li>\n\n\n\n<li><strong>Sterically<\/strong>, positions 2 and 6 are less hindered compared to position 3 (which is between the two methyl groups).<\/li>\n<\/ul>\n\n\n\n<p>This explains why only <strong>one product<\/strong> is formed in high yield. The structure of the product is:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>       CH3\n        |\n  NO2\u2014\u27f6\u27f6  \u27f6\u27f6\u2014CH3<\/code><\/pre>\n\n\n\n<p><strong>Summary<\/strong>:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Reactant<\/strong>: 1,4-dimethylbenzene (p-xylene)<\/li>\n\n\n\n<li><strong>Reagents<\/strong>: HNO\u2083\/H\u2082SO\u2084<\/li>\n\n\n\n<li><strong>Product<\/strong>: 2-nitro-1,4-dimethylbenzene<\/li>\n\n\n\n<li><strong>Molecular formula<\/strong>: C\u2088H\u2089NO\u2082<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Nitration of 1, 4-dimethylbenzene (p-xylene) gives a single product having the molecular formula C8H9NO2 in high yield. What is this product? The correct answer and explanation is : The nitration of 1,4-dimethylbenzene (p-xylene) gives 2-nitro-1,4-dimethylbenzene as the major product. Its molecular formula is C\u2088H\u2089NO\u2082. Explanation (300 words): p-Xylene is a benzene ring substituted with two [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-3203","post","type-post","status-publish","format-standard","hentry","category-quiz-questions"],"_links":{"self":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/3203","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=3203"}],"version-history":[{"count":1,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/3203\/revisions"}],"predecessor-version":[{"id":20844,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/3203\/revisions\/20844"}],"wp:attachment":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/media?parent=3203"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/categories?post=3203"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/tags?post=3203"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}