Question

Gold(III) chloride, AuCl₃, has K_sp= 3.2 x 10^-25. Calculate the molar solubility of gold(III) chloride in pure water and in various aqueous solutions.
Put your answers with 2 significant figures.

Calculate the molar solubility of gold(III) chloride in 0.010 M Au(NO₃)₃ solution.
Enter your response in scientific notation, e.g. enter 2E3 for 2000

Answer 1

1)

AuCl3   --------------> Au+3 +   3 Cl-

                                     S           3S

Ksp = [Au+3][Cl-]^3

3.2 x 10^-25 = S x (3S)^3

S = 3.3 x 10^-7

Molar solubility = 3.3 x 10^-7 M

2)

AuCl3   --------------> Au+3 +   3 Cl-

                                   0.01           3S

Ksp = [Au+3][Cl-]^3

3.2 x 10^-25 = 0.01 x (3S)^3

S = 1.06 x 10^-8 M

Molar solubility = 1.06 x 10^-8 M