The conductivity of saturated solution of Ba3(PO4)2 is 1.2 Γ 10^β5 Ξ©^β1 cm^β1. The limiting equivale β Electrochemistry Chemistry Question
Question
The conductivity of saturated solution of Ba3(PO4)2 is 1.2 Γ 10^β5 Ξ©^β1 cm^β1. The limiting equivalent conductivities of BaCl2, K3PO4 and KCl are 160, 140 and 100 Ξ©^β1 cm^2 eq^β1, respectively. The solubility product of Ba3(PO4)2 is
π‘ Solution & Explanation
Equivalent conductivity of Ba3(PO4)2 = 160 + 140 - 100 = 200 Ξ©^β1 cm^2 eq^β1. The total charge of the cation in Ba3(PO4)2 is n = 6, so molar conductivity Ξ_m = 200 Γ 6 = 1200 Ξ©^β1 cm^2 mol^β1. Solubility S = (ΞΊ Γ 1000) / Ξ_m = (1.2 Γ 10^β5 Γ 1000) / 1200 = 10^β5 M. The salt dissociates into 3 Ba^2+ and 2 PO4^3β, so Ksp = (3S)^3 Γ (2S)^2 = 108 Γ S^5 = 108 Γ (10^β5)^5 = 108 Γ 10^β25 = 1.08 Γ 10^β23. Therefore, correct answer is B.