{"id":268149,"date":"2025-07-23T20:57:17","date_gmt":"2025-07-23T20:57:17","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=268149"},"modified":"2025-07-23T20:57:19","modified_gmt":"2025-07-23T20:57:19","slug":"the-hpo42-ion-is-amphoteric-meaning-that-it-can-act-as-either-an-acid-or-a-base","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/07\/23\/the-hpo42-ion-is-amphoteric-meaning-that-it-can-act-as-either-an-acid-or-a-base\/","title":{"rendered":"The HPO42- ion is amphoteric, meaning that it can act as either an acid or a base."},"content":{"rendered":"\n

The HPO42- ion is amphoteric, meaning that it can act as either an acid or a base. Which of the following is the correct conjugate acid of this molecule?<\/p>\n\n\n\n

<\/p>\n\n\n\n

The correct conjugate acid of the HPO4^2\u2212 (hydrogen phosphate) ion is H2PO4^\u2212 (dihydrogen phosphate).<\/p>\n\n\n\n

Explanation:<\/h3>\n\n\n\n

Amphoteric substances can act as both acids and bases, depending on the conditions. The HPO4^2\u2212 ion, being amphoteric, can either donate a proton (H\u207a) to act as an acid or accept a proton to act as a base.<\/p>\n\n\n\n

    \n
  1. As an acid<\/strong>:\n
      \n
    • When HPO4^2\u2212 acts as an acid, it donates a proton (H\u207a). This leads to the formation of H2PO4^\u2212 (dihydrogen phosphate). The proton loss decreases the negative charge on the molecule from -2 to -1.<\/li>\n\n\n\n
    • The equation for this reaction is: HPO42\u2212\u2192H2PO4\u2212+H+\\text{HPO}_4^{2-} \\rightarrow \\text{H}_2\\text{PO}_4^{-} + \\text{H}^+HPO42\u2212\u200b\u2192H2\u200bPO4\u2212\u200b+H+<\/li>\n\n\n\n
    • Therefore, H2PO4^\u2212 is the conjugate acid of HPO4^2\u2212 when it behaves as an acid.<\/li>\n<\/ul>\n<\/li>\n\n\n\n
    • As a base<\/strong>:\n
        \n
      • Conversely, HPO4^2\u2212 can accept a proton (H\u207a) to act as a base, forming the PO4^3\u2212 ion (phosphate).<\/li>\n\n\n\n
      • The reaction would be: HPO42\u2212+H+\u2192PO43\u2212\\text{HPO}_4^{2-} + \\text{H}^+ \\rightarrow \\text{PO}_4^{3-}HPO42\u2212\u200b+H+\u2192PO43\u2212\u200b<\/li>\n\n\n\n
      • In this case, PO4^3\u2212 is the conjugate base of HPO4^2\u2212.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n

        Thus, the conjugate acid of HPO4^2\u2212 is H2PO4^\u2212, as it results from the proton donation, which is a key characteristic of the acid behavior of HPO4^2\u2212.<\/p>\n\n\n\n

        Ask ChatGPT<\/p>\n\n\n\n

        \"\"<\/figure>\n","protected":false},"excerpt":{"rendered":"

        The HPO42- ion is amphoteric, meaning that it can act as either an acid or a base. Which of the following is the correct conjugate acid of this molecule? The correct conjugate acid of the HPO4^2\u2212 (hydrogen phosphate) ion is H2PO4^\u2212 (dihydrogen phosphate). Explanation: Amphoteric substances can act as both acids and bases, depending on […]<\/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-268149","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/268149","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=268149"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/268149\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=268149"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=268149"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=268149"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}