1) pKa of a weak acid (HA) and pKb of a weak base (BOH) are 3.2 and 3.4 respectively. The pH of their salt (AB) solution is A) 7.2 B) 6.9 C) 7.0 D) 1.0 Answer: Option BExplanation:For a salt of the weak acid and weak base. pH=7+12pKa−12pKb Given, pKa(HA)=32,pKa(BOH)=3.4 ∴ pH=7+12(3.2)−12(3.4) =7+1.6-1.7 = 6.9