{"id":199321,"date":"2025-03-11T15:02:57","date_gmt":"2025-03-11T15:02:57","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=199321"},"modified":"2025-03-11T15:02:59","modified_gmt":"2025-03-11T15:02:59","slug":"the-number-average-molecular-weight-of-a-polystyrene-is-500000-g-mol-compute-the-degree-of-polymerization","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/03\/11\/the-number-average-molecular-weight-of-a-polystyrene-is-500000-g-mol-compute-the-degree-of-polymerization\/","title":{"rendered":"The number-average molecular weight of a polystyrene is 500,000 g\/mol. Compute the degree of polymerization"},"content":{"rendered":"\n<p>The number-average molecular weight of a polystyrene is 500,000 g\/mol. Compute the degree of polymerization.<\/p>\n\n\n\n<p><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-6-color\"><strong>The correct answer and explanation is :<\/strong><\/mark><\/p>\n\n\n\n<p>To compute the <strong>degree of polymerization (DP)<\/strong> of polystyrene, we use the formula:<\/p>\n\n\n\n<p>[<br>DP = \\frac{M_n}{M_0}<br>]<\/p>\n\n\n\n<p>where:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>( M_n ) = number-average molecular weight of the polymer (500,000 g\/mol)<\/li>\n\n\n\n<li>( M_0 ) = molecular weight of the repeating unit (for polystyrene, the repeating unit is styrene, which has a molecular weight of <strong>104.15 g\/mol<\/strong>)<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">Calculation:<\/h3>\n\n\n\n<p>[<br>DP = \\frac{500,000}{104.15} \\approx 4,800<br>]<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Explanation:<\/h3>\n\n\n\n<p>The <strong>degree of polymerization<\/strong> refers to the number of monomeric units in a polymer chain. It helps determine the physical properties of the polymer, such as strength, toughness, and viscosity.<\/p>\n\n\n\n<p>For <strong>polystyrene<\/strong>, each repeating unit (monomer) is <strong>styrene (C\u2088H\u2088)<\/strong>, which has a molecular weight of <strong>104.15 g\/mol<\/strong>. Since the given polymer has a number-average molecular weight ((M_n)) of <strong>500,000 g\/mol<\/strong>, we divide this by the molecular weight of the monomer to find how many monomers are linked together in an average polymer chain.<\/p>\n\n\n\n<p>A <strong>higher DP<\/strong> means longer polymer chains, leading to improved mechanical properties such as <strong>higher tensile strength, increased viscosity, and better impact resistance<\/strong>. However, beyond a certain limit, excessive polymer chain length may <strong>hinder processability<\/strong> due to high viscosity.<\/p>\n\n\n\n<p>In practical applications, polystyrene is widely used in packaging, insulation, and disposable containers due to its lightweight and moldability. The molecular weight and degree of polymerization significantly influence its end-use properties.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The number-average molecular weight of a polystyrene is 500,000 g\/mol. Compute the degree of polymerization. The correct answer and explanation is : To compute the degree of polymerization (DP) of polystyrene, we use the formula: [DP = \\frac{M_n}{M_0}] where: Calculation: [DP = \\frac{500,000}{104.15} \\approx 4,800] Explanation: The degree of polymerization refers to the number of [&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-199321","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/199321","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=199321"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/199321\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=199321"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=199321"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=199321"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}