{"id":198956,"date":"2025-03-10T15:17:10","date_gmt":"2025-03-10T15:17:10","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=198956"},"modified":"2025-03-10T15:17:12","modified_gmt":"2025-03-10T15:17:12","slug":"how-would-you-prepare-a-500-ml-of-a-0-20-m-solution-starting-with-solid-nah2po4h2o","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/03\/10\/how-would-you-prepare-a-500-ml-of-a-0-20-m-solution-starting-with-solid-nah2po4h2o\/","title":{"rendered":"How would you prepare a 500 mL of a 0.20 M solution starting with solid NaH2PO4*H2O"},"content":{"rendered":"\n

How would you prepare a 500 mL of a 0.20 M solution starting with solid NaH2PO4*H2O?<\/p>\n\n\n\n

The correct answer and explanation is :<\/strong><\/mark><\/p>\n\n\n\n

Answer:<\/h3>\n\n\n\n

To prepare 500 mL of a 0.20 M solution<\/strong> of sodium dihydrogen phosphate monohydrate (NaH\u2082PO\u2084\u00b7H\u2082O)<\/strong>, follow these steps:<\/p>\n\n\n\n

    \n
  1. Calculate the required mass of NaH\u2082PO\u2084\u00b7H\u2082O:<\/strong><\/li>\n<\/ol>\n\n\n\n
      \n
    • Molar mass of NaH\u2082PO\u2084\u00b7H\u2082O = 137.99 g\/mol<\/strong><\/li>\n\n\n\n
    • Desired molarity = 0.20 M<\/strong><\/li>\n\n\n\n
    • Desired volume = 500 mL = 0.500 L<\/strong><\/li>\n\n\n\n
    • Moles needed = Molarity \u00d7 Volume
      [
      0.20 \\text{ mol\/L} \\times 0.500 \\text{ L} = 0.10 \\text{ mol}
      ]<\/li>\n\n\n\n
    • Mass required = Moles \u00d7 Molar Mass
      [
      0.10 \\text{ mol} \\times 137.99 \\text{ g\/mol} = 13.80 \\text{ g}
      ]<\/li>\n<\/ul>\n\n\n\n
        \n
      1. Weigh the solid NaH\u2082PO\u2084\u00b7H\u2082O:<\/strong><\/li>\n<\/ol>\n\n\n\n
          \n
        • Use an analytical balance to measure 13.80 g<\/strong> of NaH\u2082PO\u2084\u00b7H\u2082O<\/strong> accurately.<\/li>\n<\/ul>\n\n\n\n
            \n
          1. Dissolve in distilled water:<\/strong><\/li>\n<\/ol>\n\n\n\n
              \n
            • Transfer the weighed solid to a 500 mL volumetric flask<\/strong> or a beaker.<\/li>\n\n\n\n
            • Add approximately 300-400 mL<\/strong> of distilled water<\/strong> to dissolve the solid.<\/li>\n\n\n\n
            • Stir or swirl the solution until the solid dissolves completely.<\/li>\n<\/ul>\n\n\n\n
                \n
              1. Dilute to the final volume:<\/strong><\/li>\n<\/ol>\n\n\n\n
                  \n
                • Once the solute is completely dissolved, transfer<\/strong> the solution to a 500 mL volumetric flask<\/strong> (if using a beaker).<\/li>\n\n\n\n
                • Add distilled water<\/strong> up to the 500 mL<\/strong> mark.<\/li>\n\n\n\n
                • Mix thoroughly by inverting the flask several times.<\/li>\n<\/ul>\n\n\n\n
                    \n
                  1. Final Steps:<\/strong><\/li>\n<\/ol>\n\n\n\n
                      \n
                    • Label the solution with “0.20 M NaH\u2082PO\u2084\u00b7H\u2082O”<\/strong> and store properly.<\/li>\n<\/ul>\n\n\n\n
                      \n\n\n\n

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

                      This procedure ensures accurate preparation of a 0.20 M NaH\u2082PO\u2084\u00b7H\u2082O solution. The key principle is using the molarity equation:<\/p>\n\n\n\n

                      [
                      \\text{Molarity (M)} = \\frac{\\text{moles of solute}}{\\text{liters of solution}}
                      ]<\/p>\n\n\n\n

                      By calculating the moles required and converting it into grams using the molar mass, we determine the exact amount of NaH\u2082PO\u2084\u00b7H\u2082O to weigh. The volumetric flask ensures precision when diluting to the final volume, preventing concentration errors. Mixing thoroughly ensures homogeneity, providing a uniform solution<\/strong> for experimental use.<\/p>\n","protected":false},"excerpt":{"rendered":"

                      How would you prepare a 500 mL of a 0.20 M solution starting with solid NaH2PO4*H2O? The correct answer and explanation is : Answer: To prepare 500 mL of a 0.20 M solution of sodium dihydrogen phosphate monohydrate (NaH\u2082PO\u2084\u00b7H\u2082O), follow these steps: Explanation: This procedure ensures accurate preparation of a 0.20 M NaH\u2082PO\u2084\u00b7H\u2082O solution. The […]<\/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-198956","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/198956","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=198956"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/198956\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=198956"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=198956"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=198956"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}