The correct option is A Kh=KwKa×Kb
Salt of weak acid and weak base (WA) and (WB) :
CH3COOH weak acid + NH4OH weak base ⟶CH3COONH4
Partial dissociation (Close to 100% but not exact)
CH3COONH4(aq)⟶NH+4(aq)+CH3COO−(aq)
Hydrolysis :
NH+4(aq)+CH3COO−(aq)+H2O(l)⇌CH3COOH(aq)+NH4OH(aq)
C C 0 0
C−Ch C−Ch Ch Ch
Since both the acid and the base are weak, they will exist in dissociated form.
Kh=[NH4OH][CH3COOH][NH+4][CH3COO−]
Finding KwKaKb
KwKaKb=[H3O+][OH−][CH3COO−][H3O+][CH3COOH]×[NH+4][OH−][NH4OH]KwKaKb=[NH4OH][CH3COOH][NH+4][CH3COO−]
so, KwKaKb=Kh