Construct a rough plot of pH versus volume of added base for the titration of 50 mL of 0.050 M HCN with 0.075 M NaOH. Ka = 4.0*10^-10 for HCN (a) What is the pH before any NaOH is added? pH = 5.36 (b) What volume of base, in milliliters, is required to reach the equivalence point? V= 33.33mL What is the pH at the equivalence point? pH=