What is the pH of 100 mL100 mL of a buffer that is 0.5 M HCNO0.5 M HCNO and 0.5 M CNO−0.5 M CNO− when 100 mL100 mL of a 0.2 M NaOH0.2 M NaOH solution is added? Assume the volumes are additive. KaKa of HCNOHCNO is 3.5 × 10−43.5 × 10−4 .