{"id":38139,"date":"2025-06-26T08:21:23","date_gmt":"2025-06-26T08:21:23","guid":{"rendered":"https:\/\/gaviki.com\/blog\/?p=38139"},"modified":"2025-06-26T08:21:25","modified_gmt":"2025-06-26T08:21:25","slug":"what-are-the-molecular-weights-of-the-following-compounds","status":"publish","type":"post","link":"https:\/\/gaviki.com\/blog\/what-are-the-molecular-weights-of-the-following-compounds\/","title":{"rendered":"What are the molecular weights of the following compounds"},"content":{"rendered":"\n<p>What are the molecular weights of the following compounds? NaOH, Mn2Se7, MgCl2, H3PO4.<\/p>\n\n\n\n<p><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-cyan-blue-color\">The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n<p>Here are the <strong>molecular weights<\/strong> (also known as <strong>molar masses<\/strong>) of the given compounds:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>NaOH (Sodium hydroxide)<\/strong><br>Molar mass = 22.99 (Na) + 15.999 (O) + 1.008 (H)<br><strong>= 39.997 g\/mol<\/strong><\/li>\n\n\n\n<li><strong>Mn\u2082Se\u2087 (Dimanganese heptaselenide)<\/strong><br>Molar mass = 2 \u00d7 54.938 (Mn) + 7 \u00d7 78.96 (Se)<br>= 109.876 + 552.72<br><strong>= 662.596 g\/mol<\/strong><br>Rounded: <strong>662.60 g\/mol<\/strong><\/li>\n\n\n\n<li><strong>MgCl\u2082 (Magnesium chloride)<\/strong><br>Molar mass = 24.305 (Mg) + 2 \u00d7 35.45 (Cl)<br>= 24.305 + 70.90<br><strong>= 95.205 g\/mol<\/strong><\/li>\n\n\n\n<li><strong>H\u2083PO\u2084 (Phosphoric acid)<\/strong><br>Molar mass = 3 \u00d7 1.008 (H) + 30.974 (P) + 4 \u00d7 15.999 (O)<br>= 3.024 + 30.974 + 63.996<br><strong>= 97.994 g\/mol<\/strong><br>Rounded: <strong>97.99 g\/mol<\/strong><\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Explanation<\/h3>\n\n\n\n<p>Molecular weight, or molar mass, is the mass of one mole of a chemical compound, measured in grams per mole (g\/mol). To determine this, you sum the atomic masses of all the atoms in a molecule, using values from the periodic table. Let us examine each compound individually.<\/p>\n\n\n\n<p><strong>Sodium hydroxide (NaOH)<\/strong> contains one sodium (Na), one oxygen (O), and one hydrogen (H) atom. By adding their atomic masses, we find the total molar mass is approximately 40 g\/mol. This compound is commonly used in chemistry as a strong base.<\/p>\n\n\n\n<p><strong>Dimanganese heptaselenide (Mn\u2082Se\u2087)<\/strong> contains two manganese atoms and seven selenium atoms. Manganese has a relatively high atomic mass, and selenium is even heavier. The large number of selenium atoms contributes significantly to the overall molar mass, which is about 662.60 g\/mol. This is a rare inorganic compound studied in advanced chemistry.<\/p>\n\n\n\n<p><strong>Magnesium chloride (MgCl\u2082)<\/strong> is a salt made of one magnesium ion and two chloride ions. Magnesium is a lighter metal, but the two chlorine atoms contribute a fair amount of mass. Its molar mass is around 95.21 g\/mol. This salt is commonly found in seawater and used in medicine and industry.<\/p>\n\n\n\n<p><strong>Phosphoric acid (H\u2083PO\u2084)<\/strong> contains three hydrogen atoms, one phosphorus atom, and four oxygen atoms. The high number of oxygen atoms increases its molar mass, giving a total around 97.99 g\/mol. It is widely used in fertilizers and soft drinks.<\/p>\n\n\n\n<p>Knowing molar masses is important in chemistry for converting between grams and moles, which is essential for stoichiometry and quantitative chemical analysis.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"852\" height=\"1024\" src=\"https:\/\/gaviki.com\/blog\/wp-content\/uploads\/2025\/06\/learnexams-banner8-1007.jpeg\" alt=\"\" class=\"wp-image-38147\" srcset=\"https:\/\/gaviki.com\/blog\/wp-content\/uploads\/2025\/06\/learnexams-banner8-1007.jpeg 852w, https:\/\/gaviki.com\/blog\/wp-content\/uploads\/2025\/06\/learnexams-banner8-1007-250x300.jpeg 250w, https:\/\/gaviki.com\/blog\/wp-content\/uploads\/2025\/06\/learnexams-banner8-1007-768x923.jpeg 768w\" sizes=\"auto, (max-width: 852px) 100vw, 852px\" \/><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>What are the molecular weights of the following compounds? NaOH, Mn2Se7, MgCl2, H3PO4. The Correct Answer and Explanation is: Here are the molecular weights (also known as molar masses) of the given compounds: Explanation Molecular weight, or molar mass, is the mass of one mole of a chemical compound, measured in grams per mole (g\/mol). [&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-38139","post","type-post","status-publish","format-standard","hentry","category-quiz-questions"],"_links":{"self":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/38139","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=38139"}],"version-history":[{"count":1,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/38139\/revisions"}],"predecessor-version":[{"id":38154,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/38139\/revisions\/38154"}],"wp:attachment":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/media?parent=38139"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/categories?post=38139"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/tags?post=38139"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}