{"id":39259,"date":"2025-06-27T05:23:01","date_gmt":"2025-06-27T05:23:01","guid":{"rendered":"https:\/\/gaviki.com\/blog\/?p=39259"},"modified":"2025-06-27T05:23:02","modified_gmt":"2025-06-27T05:23:02","slug":"a-sample-of-magnesium-phosphate-mg3po42-contains-72-g-of-magnesium-in-the-sample","status":"publish","type":"post","link":"https:\/\/gaviki.com\/blog\/a-sample-of-magnesium-phosphate-mg3po42-contains-72-g-of-magnesium-in-the-sample\/","title":{"rendered":"A sample of magnesium phosphate Mg3(PO4)2 contains 72 g of magnesium in the sample"},"content":{"rendered":"\n<p>A sample of magnesium phosphate Mg3(PO4)2 contains 72 g of magnesium in the sample. Calculate the number of moles of oxygen molecules in the sample.<\/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>To calculate the number of moles of <strong>oxygen molecules<\/strong> in the sample, we must first clarify what is being asked. Magnesium phosphate, with the formula Mg\u2083(PO\u2084)\u2082, contains oxygen atoms, but these are part of the compound, not free O\u2082 molecules. Since there are no molecular oxygen (O\u2082) molecules present in the compound, the question likely means the number of <strong>moles of oxygen atoms<\/strong> <strong>present in the compound<\/strong>. We&#8217;ll proceed with that interpretation.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Step 1: Molar mass of magnesium (Mg)<\/h3>\n\n\n\n<p>The atomic mass of magnesium is 24 g\/mol.<\/p>\n\n\n\n<p>Given:<br>Mass of Mg in the sample = 72 g<br>Moles of Mg = 72 g \/ 24 g\/mol = <strong>3 moles<\/strong><\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Step 2: Determine the moles of Mg\u2083(PO\u2084)\u2082<\/h3>\n\n\n\n<p>From the formula Mg\u2083(PO\u2084)\u2082, we see that each formula unit contains <strong>3 moles of Mg<\/strong>.<br>Therefore:<br>Moles of Mg\u2083(PO\u2084)\u2082 = Moles of Mg \/ 3<br>= 3 moles \/ 3 = <strong>1 mole<\/strong> of Mg\u2083(PO\u2084)\u2082<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Step 3: Determine the number of moles of oxygen atoms<\/h3>\n\n\n\n<p>Each formula unit of Mg\u2083(PO\u2084)\u2082 contains <strong>2 phosphate (PO\u2084\u00b3\u207b)<\/strong> groups.<br>Each PO\u2084 group contains <strong>4 oxygen atoms<\/strong>.<br>So, total oxygen atoms per formula unit = 2 \u00d7 4 = <strong>8 oxygen atoms<\/strong><\/p>\n\n\n\n<p>Therefore, 1 mole of Mg\u2083(PO\u2084)\u2082 contains <strong>8 moles of oxygen atoms<\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">Final Answer:<\/h3>\n\n\n\n<p><strong>8 moles of oxygen atoms<\/strong><\/p>\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>This problem involves determining the number of moles of oxygen atoms in a compound when only the amount of magnesium is given. The compound in question is magnesium phosphate, with the chemical formula Mg\u2083(PO\u2084)\u2082. To solve this, we begin by examining the atomic composition and stoichiometry of the compound.<\/p>\n\n\n\n<p>Magnesium phosphate contains three magnesium (Mg) atoms for every two phosphate (PO\u2084\u00b3\u207b) groups. The molar mass of elemental magnesium is 24 grams per mole. If the sample contains 72 grams of magnesium, we divide this by the molar mass to find the number of moles of magnesium present: 72 grams divided by 24 grams per mole gives 3 moles of magnesium.<\/p>\n\n\n\n<p>Since the chemical formula shows that three magnesium atoms are present in each unit of Mg\u2083(PO\u2084)\u2082, the number of moles of magnesium phosphate is calculated by dividing the moles of magnesium by three. This gives 1 mole of Mg\u2083(PO\u2084)\u2082.<\/p>\n\n\n\n<p>Next, we analyze the oxygen content. Each phosphate ion contains four oxygen atoms, and there are two phosphate ions in each unit of Mg\u2083(PO\u2084)\u2082. Therefore, each formula unit has 8 oxygen atoms. Since we have one mole of Mg\u2083(PO\u2084)\u2082, we have 8 moles of oxygen atoms in total.<\/p>\n\n\n\n<p>It&#8217;s important to note that these are not free oxygen molecules like O\u2082, but rather oxygen atoms chemically bonded within the phosphate groups of the compound. If the question had asked for molecular oxygen (O\u2082), the answer would be zero because no O\u2082 molecules are present in this salt. However, as interpreted, the sample contains <strong>8 moles of oxygen atoms<\/strong>.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"1024\" src=\"https:\/\/gaviki.com\/blog\/wp-content\/uploads\/2025\/06\/learnexams-banner5-247.jpeg\" alt=\"\" class=\"wp-image-39260\" srcset=\"https:\/\/gaviki.com\/blog\/wp-content\/uploads\/2025\/06\/learnexams-banner5-247.jpeg 1024w, https:\/\/gaviki.com\/blog\/wp-content\/uploads\/2025\/06\/learnexams-banner5-247-300x300.jpeg 300w, https:\/\/gaviki.com\/blog\/wp-content\/uploads\/2025\/06\/learnexams-banner5-247-150x150.jpeg 150w, https:\/\/gaviki.com\/blog\/wp-content\/uploads\/2025\/06\/learnexams-banner5-247-768x768.jpeg 768w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>A sample of magnesium phosphate Mg3(PO4)2 contains 72 g of magnesium in the sample. Calculate the number of moles of oxygen molecules in the sample. The Correct Answer and Explanation is: To calculate the number of moles of oxygen molecules in the sample, we must first clarify what is being asked. Magnesium phosphate, with the [&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-39259","post","type-post","status-publish","format-standard","hentry","category-quiz-questions"],"_links":{"self":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/39259","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=39259"}],"version-history":[{"count":2,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/39259\/revisions"}],"predecessor-version":[{"id":39262,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/39259\/revisions\/39262"}],"wp:attachment":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/media?parent=39259"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/categories?post=39259"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/tags?post=39259"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}