To simulate the pH of blood, which is 7.4, an undergraduate researcher in a biology lab produced a buffer solution by dissolving sodium dihydrogen phosphate (K_a= 6.2 * 10^-⁸) and sodium hydrogen phosphate (K_a= 3.6* 10^-¹³) together in an aqueous solution. What mole ratio of Na₂HPO₄/NaH₂PO₄ did she need to use?

Question

Quizplus · Accepted Answer

The Henderson-Hasselbalch equation is used to calculate the pH of a buffer solution. For the phosphate buffer system, pH = pKa + log([A-]/[HA]). Given pH = 7.4 and pKa = 7.2 (calculated from the given Ka values), the ratio [A-]/[HA] is approximately 1.6.

To Simulate the PH of Blood, Which Is 7