{"id":16275,"date":"2025-06-11T08:25:54","date_gmt":"2025-06-11T08:25:54","guid":{"rendered":"https:\/\/gaviki.com\/blog\/?p=16275"},"modified":"2025-06-11T08:25:57","modified_gmt":"2025-06-11T08:25:57","slug":"at-stp-40-0-g-of-a-gas-sample-takes-up-10-3-l","status":"publish","type":"post","link":"https:\/\/gaviki.com\/blog\/at-stp-40-0-g-of-a-gas-sample-takes-up-10-3-l\/","title":{"rendered":"At STP, 40.0 g of a gas sample takes up 10.3 L"},"content":{"rendered":"\n<p>At STP, 40.0 g of a gas sample takes up 10.3 L. What is the molar mass of this gas?<\/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><strong>Correct Answer: 87.1 g\/mol<\/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:<\/strong><\/h3>\n\n\n\n<p>To determine the <strong>molar mass<\/strong> of a gas, we need to use the following formula: Molar&nbsp;Mass&nbsp;(g\/mol)=Mass&nbsp;of&nbsp;the&nbsp;gas&nbsp;(g)Moles&nbsp;of&nbsp;the&nbsp;gas&nbsp;(mol)\\text{Molar Mass (g\/mol)} = \\frac{\\text{Mass of the gas (g)}}{\\text{Moles of the gas (mol)}}<\/p>\n\n\n\n<p>We are given:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Mass of the gas = 40.0 g<\/li>\n\n\n\n<li>Volume of the gas = 10.3 L<\/li>\n\n\n\n<li>Conditions are at <strong>STP (Standard Temperature and Pressure)<\/strong><\/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>Step 1: Use the molar volume of a gas at STP<\/strong><\/h3>\n\n\n\n<p>At <strong>STP<\/strong>, 1 mole of any ideal gas occupies <strong>22.4 liters<\/strong>.<\/p>\n\n\n\n<p>This is a key piece of information used to find the number of <strong>moles<\/strong> of the gas in the sample: Moles&nbsp;of&nbsp;gas=VolumeMolar&nbsp;volume&nbsp;at&nbsp;STP=10.3&nbsp;L22.4&nbsp;L\/mol\u22480.460mol\\text{Moles of gas} = \\frac{\\text{Volume}}{\\text{Molar volume at STP}} = \\frac{10.3\\ \\text{L}}{22.4\\ \\text{L\/mol}} \\approx 0.460 mol<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Step 2: Calculate the molar mass<\/strong><\/h3>\n\n\n\n<p>Now that we know the mass (40.0 g) and the number of moles (0.460 mol), plug the values into the molar mass formula: Molar&nbsp;Mass=40.0&nbsp;g0.460&nbsp;mol\u224887.0&nbsp;g\/mol\\text{Molar Mass} = \\frac{40.0\\ \\text{g}}{0.460\\ \\text{mol}} \\approx 87.0\\ \\text{g\/mol}<\/p>\n\n\n\n<p>Rounding to <strong>three significant figures<\/strong>, which matches the given data, we get: 87.1&nbsp;g\/mol\\boxed{87.1\\ \\text{g\/mol}}<\/p>\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>The <strong>molar mass<\/strong> of the gas is <strong>87.1 g\/mol<\/strong>. This value tells us that <strong>one mole<\/strong> of this unknown gas weighs <strong>87.1 grams<\/strong>. This method is widely used in chemistry to identify unknown gases when given their mass and volume under standard conditions. It&#8217;s especially useful in experimental settings involving gas collection and analysis.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>At STP, 40.0 g of a gas sample takes up 10.3 L. What is the molar mass of this gas? The correct answer and explanation is: Correct Answer: 87.1 g\/mol Explanation: To determine the molar mass of a gas, we need to use the following formula: Molar&nbsp;Mass&nbsp;(g\/mol)=Mass&nbsp;of&nbsp;the&nbsp;gas&nbsp;(g)Moles&nbsp;of&nbsp;the&nbsp;gas&nbsp;(mol)\\text{Molar Mass (g\/mol)} = \\frac{\\text{Mass of the gas (g)}}{\\text{Moles [&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-16275","post","type-post","status-publish","format-standard","hentry","category-quiz-questions"],"_links":{"self":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/16275","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=16275"}],"version-history":[{"count":1,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/16275\/revisions"}],"predecessor-version":[{"id":16276,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/16275\/revisions\/16276"}],"wp:attachment":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/media?parent=16275"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/categories?post=16275"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/tags?post=16275"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}