According to hydrolysis of salts of a weak acid and a weak base, Since, the hydrolysis of such salts will form weak acid and weak base, the solution will be neutral and its pH will be 7 . Then, B+A−+H2O⇌
HA
Weakacid
+
BOH
Weakbase
Kh=
[HA][BOH]
[B+][A−]
Now, let consider the dissociation of HA and BOH. HA⇌H++A− BOH⇌B++OH− Ka=
[H+][A−]
[HA]
Kb=
[B]+][OH−]
[HA][BOH−]
Also, we know that Kw=[H+][OH−] Now, put the value of Ka and Kb in above equation. Kh=