{"id":147157,"date":"2024-10-02T12:06:35","date_gmt":"2024-10-02T12:06:35","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=147157"},"modified":"2024-10-02T12:06:40","modified_gmt":"2024-10-02T12:06:40","slug":"a-20-00-g-mixture-of-magnesium-and-zinc-metal-reacting-with-excess-hydrochloric-acid-produced-1-242-g-of-hydrogen-gas","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2024\/10\/02\/a-20-00-g-mixture-of-magnesium-and-zinc-metal-reacting-with-excess-hydrochloric-acid-produced-1-242-g-of-hydrogen-gas\/","title":{"rendered":"A 20.00 g mixture of magnesium and zinc metal reacting with excess hydrochloric acid produced 1.242 g of hydrogen gas."},"content":{"rendered":"\n<p>A 20.00 g mixture of magnesium and zinc metal reacting with excess hydrochloric acid produced 1.242 g of hydrogen gas. What is the percent zinc in the original mixture<\/p>\n\n\n\n<p><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-6-color\">The correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n<p>To solve this problem, we need to determine the percent composition of zinc in a mixture of magnesium (Mg) and zinc (Zn) that reacts with hydrochloric acid (HCl) to produce hydrogen gas (H\u2082).<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Step-by-step Approach:<\/h3>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Reactions Involved<\/strong>:<ul><li>Magnesium reacts with hydrochloric acid: Mg+2HCl\u2192MgCl2+H2\\text{Mg} + 2\\text{HCl} \\rightarrow \\text{MgCl}_2 + \\text{H}_2Mg+2HCl\u2192MgCl2\u200b+H2\u200b<\/li><li>Zinc reacts similarly: Zn+2HCl\u2192ZnCl2+H2\\text{Zn} + 2\\text{HCl} \\rightarrow \\text{ZnCl}_2 + \\text{H}_2Zn+2HCl\u2192ZnCl2\u200b+H2\u200b<\/li><\/ul>Both reactions produce hydrogen gas, but the amounts of gas depend on the masses of the metals involved.<\/li>\n\n\n\n<li><strong>Mass of Hydrogen Gas<\/strong>: The reaction produced 1.242 g of hydrogen gas. Using the molar mass of hydrogen gas (H\u2082), which is 2.016 g\/mol, we calculate the moles of hydrogen gas produced:Moles\u00a0of\u00a0H2=1.242\u00a0g2.016\u00a0g\/mol=0.616\u00a0mol\\text{Moles of H}_2 = \\frac{1.242 \\text{ g}}{2.016 \\text{ g\/mol}} = 0.616 \\text{ mol}Moles\u00a0of\u00a0H2\u200b=2.016\u00a0g\/mol1.242\u00a0g\u200b=0.616\u00a0mol<\/li>\n\n\n\n<li><strong>Stoichiometric Relationships<\/strong>: According to the reactions, 1 mole of magnesium or 1 mole of zinc produces 1 mole of hydrogen gas. Therefore, the total moles of hydrogen gas is equivalent to the total moles of magnesium and zinc involved in the reaction:nMg+nZn=0.616\u00a0moln_{\\text{Mg}} + n_{\\text{Zn}} = 0.616 \\text{ mol}nMg\u200b+nZn\u200b=0.616\u00a0mol<\/li>\n\n\n\n<li><strong>Mass Relationships<\/strong>: The molar mass of magnesium is 24.305 g\/mol, and the molar mass of zinc is 65.38 g\/mol. The mass of the metals in the mixture can be expressed as:Mass\u00a0of\u00a0Mg=nMg\u00d724.305\u00a0g\/mol\\text{Mass of Mg} = n_{\\text{Mg}} \\times 24.305 \\text{ g\/mol}Mass\u00a0of\u00a0Mg=nMg\u200b\u00d724.305\u00a0g\/mol Mass\u00a0of\u00a0Zn=nZn\u00d765.38\u00a0g\/mol\\text{Mass of Zn} = n_{\\text{Zn}} \\times 65.38 \\text{ g\/mol}Mass\u00a0of\u00a0Zn=nZn\u200b\u00d765.38\u00a0g\/molThe total mass of the metals is given as 20.00 g:nMg\u00d724.305+nZn\u00d765.38=20.00\u00a0gn_{\\text{Mg}} \\times 24.305 + n_{\\text{Zn}} \\times 65.38 = 20.00 \\text{ g}nMg\u200b\u00d724.305+nZn\u200b\u00d765.38=20.00\u00a0g<\/li>\n\n\n\n<li><strong>Solving the System of Equations<\/strong>: We have two equations:nMg+nZn=0.616\u00a0moln_{\\text{Mg}} + n_{\\text{Zn}} = 0.616 \\text{ mol}nMg\u200b+nZn\u200b=0.616\u00a0mol nMg\u00d724.305+nZn\u00d765.38=20.00\u00a0gn_{\\text{Mg}} \\times 24.305 + n_{\\text{Zn}} \\times 65.38 = 20.00 \\text{ g}nMg\u200b\u00d724.305+nZn\u200b\u00d765.38=20.00\u00a0gSolving these simultaneously gives nZn\u22480.243\u00a0moln_{\\text{Zn}} \\approx 0.243 \\text{ mol}nZn\u200b\u22480.243\u00a0mol.<\/li>\n\n\n\n<li><strong>Mass of Zinc<\/strong>:Mass\u00a0of\u00a0Zn=0.243\u00a0mol\u00d765.38\u00a0g\/mol=15.89\u00a0g\\text{Mass of Zn} = 0.243 \\text{ mol} \\times 65.38 \\text{ g\/mol} = 15.89 \\text{ g}Mass\u00a0of\u00a0Zn=0.243\u00a0mol\u00d765.38\u00a0g\/mol=15.89\u00a0g<\/li>\n\n\n\n<li><strong>Percent Zinc<\/strong>:Percent\u00a0Zn=15.89\u00a0g20.00\u00a0g\u00d7100=79.45%\\text{Percent Zn} = \\frac{15.89 \\text{ g}}{20.00 \\text{ g}} \\times 100 = 79.45\\%Percent\u00a0Zn=20.00\u00a0g15.89\u00a0g\u200b\u00d7100=79.45%<\/li>\n<\/ol>\n\n\n\n<p>Thus, the percent zinc in the original mixture is approximately <strong>79.45%<\/strong>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Explanation:<\/h3>\n\n\n\n<p>In this problem, we calculated the percent zinc by analyzing the amount of hydrogen gas produced in a reaction between a metal mixture and hydrochloric acid. By determining the number of moles of hydrogen gas and using the stoichiometric relationships of the reactions, we solved for the moles of each metal. The total mass of the metals allowed us to solve the system of equations and find the mass and percent composition of zinc in the mixture.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>A 20.00 g mixture of magnesium and zinc metal reacting with excess hydrochloric acid produced 1.242 g of hydrogen gas. What is the percent zinc in the original mixture The correct Answer and Explanation is: To solve this problem, we need to determine the percent composition of zinc in a mixture of magnesium (Mg) and [&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-147157","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/147157","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=147157"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/147157\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=147157"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=147157"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=147157"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}