A chemist wishes to prepare 250mL of a buffer that is pH = 4.50. Beginning with 100mL of 0.12 mol L^(-1) acetic acid and a supply of 0.10 mol L^(-1) NaOH, explain how this could be done. How much 0.20 mol L^(-1) NaOH must be added to this buffer to raise the pH to 5.1? If the same amount of 0.20 mol L^(-1) NaOH were added to 250 mL of deionized water, what would the new pH be?