{"id":256174,"date":"2025-07-14T04:42:52","date_gmt":"2025-07-14T04:42:52","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=256174"},"modified":"2025-07-14T04:42:54","modified_gmt":"2025-07-14T04:42:54","slug":"phosphate-po4-polyatomic-ion-that-can-combine-with-any-cation-to-form-an-ionic-compound","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/07\/14\/phosphate-po4-polyatomic-ion-that-can-combine-with-any-cation-to-form-an-ionic-compound\/","title":{"rendered":"Phosphate; PO4 polyatomic ion that can combine with any cation to form an ionic compound."},"content":{"rendered":"\n

Phosphate; PO4 polyatomic ion that can combine with any cation to form an ionic compound. Identify all the formulas below that correctly represent phosphate compounds. Select one or more: Combined with magnesium: Mg3(PO4)2 Combined with iron(III): Fe3(PO4)2 Combined with iron(II): FePO4 Combined with lithium: Li3PO4 Combined with copper(V): Cu3(PO4)2 Combined with copper(II): CuPO4 Combined with magnesium: Mg3(PO4)2<\/p>\n\n\n\n

The Correct Answer and Explanation is:<\/mark><\/strong><\/p>\n\n\n\n

The formula for phosphate is PO\u2084\u00b3\u207b<\/strong>. When phosphate combines with a cation, the charges of the cation and anion must balance out to form a neutral compound. Let’s analyze each option based on the charges of the cations involved:<\/p>\n\n\n\n

    \n
  1. Mg\u2083(PO\u2084)\u2082 (Combined with magnesium)<\/strong>:\n
      \n
    • Magnesium has a charge of +2 (Mg\u00b2\u207a<\/strong>).<\/li>\n\n\n\n
    • To balance the charge of the phosphate ion (PO\u2084\u00b3\u207b<\/strong>), three magnesium ions (+2 each) will balance the charge of two phosphate ions, which each have a charge of -3. Therefore, Mg\u2083(PO\u2084)\u2082<\/strong> is correct.<\/li>\n<\/ul>\n<\/li>\n\n\n\n
    • Fe\u2083(PO\u2084)\u2082 (Combined with iron(III))<\/strong>:\n
        \n
      • Iron(III) has a charge of +3 (Fe\u00b3\u207a<\/strong>).<\/li>\n\n\n\n
      • Three iron(III) ions (each with a charge of +3) balance the charge of two phosphate ions (each with a charge of -3). Therefore, Fe\u2083(PO\u2084)\u2082<\/strong> is correct.<\/li>\n<\/ul>\n<\/li>\n\n\n\n
      • FePO\u2084 (Combined with iron(II))<\/strong>:\n
          \n
        • Iron(II) has a charge of +2 (Fe\u00b2\u207a<\/strong>).<\/li>\n\n\n\n
        • To balance the charge of the phosphate ion (PO\u2084\u00b3\u207b<\/strong>), only one iron(II) ion (+2) will not be sufficient to balance the charge of phosphate, which is -3. Therefore, FePO\u2084<\/strong> is incorrect<\/strong>.<\/li>\n<\/ul>\n<\/li>\n\n\n\n
        • Li\u2083PO\u2084 (Combined with lithium)<\/strong>:\n
            \n
          • Lithium has a charge of +1 (Li\u207a<\/strong>).<\/li>\n\n\n\n
          • To balance the charge of one phosphate ion (PO\u2084\u00b3\u207b), three lithium ions are required. Therefore, Li\u2083PO\u2084<\/strong> is correct.<\/li>\n<\/ul>\n<\/li>\n\n\n\n
          • Cu\u2083(PO\u2084)\u2082 (Combined with copper(V))<\/strong>:\n
              \n
            • Copper(V) is a rare oxidation state, with a charge of +5 (Cu\u2075\u207a<\/strong>).<\/li>\n\n\n\n
            • To balance the charge of two phosphate ions (each with a charge of -3), three copper ions (each with a charge of +5) would be needed. Therefore, Cu\u2083(PO\u2084)\u2082<\/strong> is correct.<\/li>\n<\/ul>\n<\/li>\n\n\n\n
            • CuPO\u2084 (Combined with copper(II))<\/strong>:\n
                \n
              • Copper(II) has a charge of +2 (Cu\u00b2\u207a<\/strong>).<\/li>\n\n\n\n
              • One copper(II) ion and one phosphate ion would not balance, as the charges do not match. Therefore, CuPO\u2084<\/strong> is incorrect<\/strong>.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n

                Correct answers<\/strong>:<\/p>\n\n\n\n

                  \n
                • Mg\u2083(PO\u2084)\u2082<\/strong><\/li>\n\n\n\n
                • Fe\u2083(PO\u2084)\u2082<\/strong><\/li>\n\n\n\n
                • Li\u2083PO\u2084<\/strong><\/li>\n\n\n\n
                • Cu\u2083(PO\u2084)\u2082<\/strong><\/li>\n<\/ul>\n\n\n\n
                  \"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

                  Phosphate; PO4 polyatomic ion that can combine with any cation to form an ionic compound. Identify all the formulas below that correctly represent phosphate compounds. Select one or more: Combined with magnesium: Mg3(PO4)2 Combined with iron(III): Fe3(PO4)2 Combined with iron(II): FePO4 Combined with lithium: Li3PO4 Combined with copper(V): Cu3(PO4)2 Combined with copper(II): CuPO4 Combined with […]<\/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-256174","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/256174","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=256174"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/256174\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=256174"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=256174"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=256174"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}