(a) Prepare a family of graphs for the titration of 50.0 mL of 0.0200 M HA (pKa 4.00) with 0.100 M B (pKb = 3.00, 6.00, and 9.00).

(b) Write the acid-base reaction that occurs when acetic acid and sodium benzoate (the salt of benzoic acid) are mixed, and find the equilibrium constant for the reaction. Find the pH of a solution prepared by mixing 212 mL of 0.200 M acetic acid with 325 mL of 0.050 0 M sodium benzoate.