The K_sp for the solubility equilibrium of AgCl is 1.8 x 10^-10. If we mix 0.00010 M Ag⁺¹ solution and 0.010 M Cl^-1, what will be the percentage of Ag⁺¹ which is removed by precipitation? Is this process useful for quantitative analysis of Ag⁺¹?

Answer:

AgCl (s) < ----------- > Ag^+ (aq) + Cl^- (aq)

Solubility product expression is,

Ksp = [Ag^+][Cl^-]

1.8 x 10^-10 = [Ag^+](0.010)

[Ag^+] = 1.8 x 10^-10 / 0.010

[Ag^+] = 1.8 x 10^-8 M

[Ag^+] = 0.000000018 M

But we have 0.00010 M of Ag+ ions. Among them 0.000000018 M of Ag+ ions get removed as precipitate.

Therefore,

% of Ag^+ ions by precipitate = 0.000000018 x 100 / 0.00010 = 0.018 %

Yes it is useful to estimate Ag^+ ions quantitatively.