Question

Use the Ksp values to calculate the molar solubility of each of the following compounds in pure water. (Express answers in moles per liter)

1) MX(Ksp = 9.10

Answer 1

If a salt dissociates into ints ions then the solubility is calculated as

1) we know that Ksp = [M+][X-] = 9.1 X 10^-11

As [M+] = [X-] , let it be = x

so x² = 9.1 X 10^-11

x = 0.95 X 10^-6

^tThis is molar solubility of MX

2) Ag2CrO4 -> 2Ag+ + CrO4^-2

so Ksp = [Ag+]² [CrO4^-2]²

^oone mole of Ag2CrO4 will give let 2x mole of Ag+ and and x mole of CrO4-2

so Ksp = (2x)2 (x) = 1.12 X 10^-12

4x^3 = 1.12X 10^-12

so x3 = 0.28 X 10^-12

x = 0.654 X 10^-4

3. Ca(OH)2 --> Ca⁺² + 2OH-

Ksp = [Ca⁺²][2OH^-]

Ksp = x X x² = 2x² = 4.68 X 10^-6

x² = 2.34 X 10^-6

x = 1.52 X 10^-3 M