Exercise 5 | Solubility and Precipitation Reactions

Calculate the solubility of Ag2CO3 (s) in g.L-1 in an aqueous solution that is 0.10 M in AgNO3 (aq).


Data: Ksp (Ag2CO3) = 8.5 x 10-12 3

Chemical equation:

Ag2CO3 (s)  2 Ag+ (aq) + CO32- (aq)


At equilibrium:

[Ag+] = 0.10 + 2s

[CO32-] = s

Ksp = [Ag+]2[CO32-] = (0.10+2s)2 x s


Hypothesis 2s << 0.10

⇒ Ksp = 0.102 x s

⇒ s = 8.5 x 10-10 M (the hypothesis is verified)


S = solubility of Ag2CO3 (s) in g.L-1 = s x MAg2CO3

⇒ S = 2.3 x 10-7 g.L-1