The ionisation constant of ammonium hydroxide is 1.77 10⁻⁵ at 298 ~K . Hydrolysis constant of ammonium chloride is

Step-by-step solution

Given, K _ a ( NH ₄ OH )=1.77 10⁻⁵ aligned & NH ₄ OH NH ₄⁺+ OH ⁻ & K _ a = [ NH ₄⁺ ] [ OH ⁻ ] [ NH ₄ OH ] =1.77 10⁻⁵ aligned Hydrolysis of NH ₄ Cl takes place as, NH ₄ Cl + H ₂ O NH ₄ OH + HCl or NH ₄⁺+ H ₂ O NH ₄ OH + H ⁺ Hydrolysis constant , K _ h = [ NH ₄ OH ] [ H ⁺ ] [ NH ₄⁺ ] or K _ h = [ NH ₄ OH ] [ H ⁺ ] [ OH ⁻ ] [ NH ₄⁺ ] [ OH ⁻ ] From Eqs (i) and (iii) aligned K _ h & = K _ w K _ a [ [ H ⁺ ] [ OH ⁻ ]= K _ w ] & = 10⁻¹⁴ 1.77 10⁻⁵ & =5.65 10⁻¹⁰ aligned