Question

Consider a buffer solution that contains 0.50 M NaH2PO4 and 0.20 M Na2HPO4. pKa(H2PO4-)=7.21. a) Calculate the pH. b)Calculate the change in pH if 0.120 g of solid NaOH is added to 150 mL of this solution. c) If the acceptable buffer range of the solution is ±0.10 pH units, calculate how many moles of H3O+ can be neutralized by 250 mL of the initial buffer.