Determine the boiling point of a solution that contains 78.8 g of naphthalene (C10H8, molar mass = 128.16 g\/mol) dissolved in 722 mL of benzene (d = 0.877 g\/mL). Pure benzene has a boiling point of 80.1\u00c3\u201a\u00c2\u00b0C and a boiling point elevation constant of 2.53\u00c3\u201a\u00c2\u00b0C\/m.<\/p>\n\n\n\n
The Correct Answer and Explanation is :<\/strong><\/mark><\/p>\n\n\n\n The boiling point of the solution is approximately 82.56\u00b0C<\/strong>.<\/p>\n\n\n\n To determine the boiling point of a solution, we need to use the formula for boiling point elevation:<\/p>\n\n\n\n [ Where:<\/p>\n\n\n\n Here are the detailed steps:<\/p>\n\n\n\n This method shows how the presence of a solute (naphthalene) raises the boiling point of the solvent (benzene).<\/p>\n","protected":false},"excerpt":{"rendered":" Determine the boiling point of a solution that contains 78.8 g of naphthalene (C10H8, molar mass = 128.16 g\/mol) dissolved in 722 mL of benzene (d = 0.877 g\/mL). Pure benzene has a boiling point of 80.1\u00c3\u201a\u00c2\u00b0C and a boiling point elevation constant of 2.53\u00c3\u201a\u00c2\u00b0C\/m. The Correct Answer and Explanation is : The boiling point […]<\/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-193617","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/193617","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=193617"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/193617\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=193617"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=193617"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=193617"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}Explanation:<\/h3>\n\n\n\n
\\Delta T_b = i \\cdot K_b \\cdot m
]<\/p>\n\n\n\n\n
\n
Using the mass of naphthalene and its molar mass:
[
\\text{moles of naphthalene} = \\frac{78.8 \\, \\text{g}}{128.16 \\, \\text{g\/mol}} = 0.615 \\, \\text{mol}
]<\/li>\n\n\n\n
Using the density and volume of benzene:
[
\\text{mass of benzene} = 722 \\, \\text{mL} \\times 0.877 \\, \\text{g\/mL} = 633.5 \\, \\text{g} = 0.6335 \\, \\text{kg}
]<\/li>\n\n\n\n
Molality (m) is moles of solute per kilogram of solvent:
[
m = \\frac{0.615 \\, \\text{mol}}{0.6335 \\, \\text{kg}} = 0.970 \\, \\text{mol\/kg}
]<\/li>\n\n\n\n
Using the formula for boiling point elevation:
[
\\Delta T_b = 2.53 \\, \\text{\u00b0C\/m} \\times 0.970 \\, \\text{mol\/kg} = 2.45 \\, \\text{\u00b0C}
]<\/li>\n\n\n\n
The new boiling point is the sum of the pure benzene boiling point and the elevation:
[
\\text{New boiling point} = 80.1 \\, \\text{\u00b0C} + 2.45 \\, \\text{\u00b0C} = 82.56 \\, \\text{\u00b0C}
]<\/li>\n<\/ol>\n\n\n\n