Question

The solubility of Mg(OH)₂ is increased by addition of NH₄⁺ ion. Find 

(i) K_c for the reaction

Mg(OH)₂ + 2NH₄⁺ ⇌ 2NH₃ + 2H₂O + Mg²⁺ 

(ii) Calculate solubility of Mg(OH)₂ in a solution containing 0.5 M NH₄Cl

(K_{sp [Mg(OH)2]} = 1.0 × 10^–11, K_b(NH3) = 1.8 × 10^–5)

Answer 1

(i) For the reaction

(ii) Now, let us, assume that 'a' moles of Mg(OH)₂ be dissolved in presence of 0.5 M NH₄Cl.