Question

MX (Ksp = 5.67×10⁻³⁶)

Use the Ksp values to calculate the molar solubility of each of the following compounds in pure water.

Answer 1

No compounds are given, hence I am using the generic formula of a salt MX where it dissociates to give M+ metal ion and X- halide ion.

The dissociation equilibrium reaction can be written as:

MX(s)   M+(aq) + X-(aq)

Ksp = [M+] [X-] / [MX]

As Ksp is very very low we can consider [MX] to be constant.

Ksp = [M+] [X-] =  5.67×10^−36

Let's say [M+] = [X-] = x

then x^2 =  5.67×10^−36

x = (5.67×10^−36)^0.5

x = 2.3812*10^-18 M

Thus the molar solubility of MX is 2.3812*10^-18 M.