describe how to prepare 1 liter of 0.05 molar buffer solution with pH 7.4 of potassium phosphate?

Question

how to prepare a buffer solution, 1L-volume, 0.05-Concentration, pH-7.4

Answer 1

Weigh out 0.05 moles of KH2PO4 and dissolve it in about 800 mL of water. Using a pH meter raise the pH of the solution to 7.4 by slowly adding KOH to the solution. When the pH is 7.4, add water to give a final volume of 1.0 L.

When you dissolve KH2PO4, the pH of the solution will be less than 7, and so you can simply add KOH to neutralize the H2PO4- ions, converting them to HPO4^2- ions.

Alternatively, you could make two solutions: 0.05 M KH2PO4 and 0.05 M K2HPO4 and pour them together until the pH is 7.4. The end result will be the same either way.

Answer 2

Mysterious

Answer 3

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K3PO4