{"id":16324,"date":"2025-06-11T08:53:18","date_gmt":"2025-06-11T08:53:18","guid":{"rendered":"https:\/\/gaviki.com\/blog\/?p=16324"},"modified":"2025-06-11T08:53:19","modified_gmt":"2025-06-11T08:53:19","slug":"write-the-formula-of-the-salts-used-to-make-a-phosphate-buffer","status":"publish","type":"post","link":"https:\/\/gaviki.com\/blog\/write-the-formula-of-the-salts-used-to-make-a-phosphate-buffer\/","title":{"rendered":"Write the formula of the salts used to make a phosphate buffer"},"content":{"rendered":"\n<p>Write the formula of the salts used to make a phosphate buffer<\/p>\n\n\n\n<p><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-vivid-cyan-blue-color\"><strong>The correct answer and explanation is:<\/strong><\/mark><\/p>\n\n\n\n<p><strong>Correct Answer:<\/strong><br>The salts commonly used to make a phosphate buffer are:<\/p>\n\n\n\n<p><strong>NaH\u2082PO\u2084 (sodium dihydrogen phosphate)<\/strong> and <strong>Na\u2082HPO\u2084 (disodium hydrogen phosphate)<\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Explanation (300 words):<\/strong><\/h3>\n\n\n\n<p>A <strong>phosphate buffer<\/strong> is widely used in biological and chemical laboratories because it maintains a stable pH in the physiological range (around pH 6.8 to 7.4). This buffer is based on the equilibrium between two forms of phosphate ions:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>H\u2082PO\u2084\u207b (dihydrogen phosphate ion)<\/strong> \u2014 the weak acid<\/li>\n\n\n\n<li><strong>HPO\u2084\u00b2\u207b (hydrogen phosphate ion)<\/strong> \u2014 the conjugate base<\/li>\n<\/ul>\n\n\n\n<p>To prepare this buffer, two salts are typically used:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Sodium dihydrogen phosphate (NaH\u2082PO\u2084)<\/strong> provides the <strong>H\u2082PO\u2084\u207b<\/strong> ion (acidic component).<\/li>\n\n\n\n<li><strong>Disodium hydrogen phosphate (Na\u2082HPO\u2084)<\/strong> provides the <strong>HPO\u2084\u00b2\u207b<\/strong> ion (basic component).<\/li>\n<\/ul>\n\n\n\n<p>These two components form a <strong>conjugate acid\u2013base pair<\/strong>, which resists changes in pH by neutralizing added acids or bases. The key chemical equilibrium involved is: H2PO4\u2212\u21cbH++HPO42\u2212\\text{H}_2\\text{PO}_4^- \\leftrightharpoons \\text{H}^+ + \\text{HPO}_4^{2-}<\/p>\n\n\n\n<p>This system follows the <strong>Henderson-Hasselbalch equation<\/strong>, which is used to calculate the pH of the buffer: pH=pKa+log\u2061([base][acid])\\text{pH} = \\text{p}K_a + \\log \\left( \\frac{[\\text{base}]}{[\\text{acid}]} \\right)<\/p>\n\n\n\n<p>For phosphate, the relevant pKa is approximately <strong>7.2<\/strong> (for the second dissociation of phosphoric acid). By adjusting the ratio of Na\u2082HPO\u2084 to NaH\u2082PO\u2084, you can create a buffer at a desired pH near this value.<\/p>\n\n\n\n<p>Phosphate buffers are preferred in many biological applications because:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>They are non-toxic to cells.<\/li>\n\n\n\n<li>They maintain pH near physiological conditions.<\/li>\n\n\n\n<li>They have good buffering capacity in the pH 6\u20138 range.<\/li>\n<\/ul>\n\n\n\n<p>However, phosphate can <strong>precipitate with divalent metal ions<\/strong> (e.g., Ca\u00b2\u207a, Mg\u00b2\u207a), which must be considered in biochemical experiments.<\/p>\n\n\n\n<p>In summary, <strong>NaH\u2082PO\u2084 and Na\u2082HPO\u2084<\/strong> are the salts used to create an effective phosphate buffer system that helps maintain a stable pH in biological and chemical environments.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Write the formula of the salts used to make a phosphate buffer The correct answer and explanation is: Correct Answer:The salts commonly used to make a phosphate buffer are: NaH\u2082PO\u2084 (sodium dihydrogen phosphate) and Na\u2082HPO\u2084 (disodium hydrogen phosphate). Explanation (300 words): A phosphate buffer is widely used in biological and chemical laboratories because it maintains [&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-16324","post","type-post","status-publish","format-standard","hentry","category-quiz-questions"],"_links":{"self":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/16324","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=16324"}],"version-history":[{"count":1,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/16324\/revisions"}],"predecessor-version":[{"id":16325,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/posts\/16324\/revisions\/16325"}],"wp:attachment":[{"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/media?parent=16324"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/categories?post=16324"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gaviki.com\/blog\/wp-json\/wp\/v2\/tags?post=16324"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}