A 0.5 M buffer will require five times as much acid or base as a 0.1 M buffer for a given pH change.
Starting with 65 mL of 0.50 M phosphate buffer, pH = 6.75, you add 3.7 mL of 1.00 M HCl. Using the Henderson Hasselbalch equation with a pK2 for phosphate of 6.64, calculate the following values.
What is the composition of the buffer to begin with, both in terms of the concentration and the molar quantity of the two major phosphate species?
Concentration of HPO42-: ?
Concentration of H2PO4-: ?
Molar quantity of HPO42-: ?
Molar quantity of H2PO4-: ?