Exercise 1 | Solubility and Precipitation Reactions

General Chemistry 3 - Exercise 1

Calculate the solubility in g.L-1 of AgBr (s) in pure water given that Ksp = 5.40 x 10-13 M 2

Chemical equation:

AgBr (s) ⇄ Ag+ (aq) + Br- (aq)


Pure water: the only source of Ag+ and Br- is AgBr

From the reaction stoichiometry: [Ag+] = [Br-]

s = solubility of AgBr (s) in M = [Ag+] = [Br-]


Ksp = [Ag+][Br-]

Ksp = s2

⇒ s = 7.35 x 10-7 M


S = solubility of AgBr (s) in g.L-1 = s x MAgBr

⇒ S = 1.38 x 10-4 g.L-1