Help ASAP please

Question

The Ksp is 6.6 x 10-6. What is the molar solubility of this solid in mol/L ? Show all steps of this calculation.

Answer 1

It would help to know the identity of the solid since that will allow us to write a correct Ksp expression. If we assume a monovalent cation and anion, such as XY, then we have ...

XY(s) <==> X⁺(aq) + Y^-(aq)

Ksp = [X⁺][Y^-]

6.6x10^-6 = (x)(x)

x = 2.6x10^-3 M = molar solubility of XY

If you have a divalent cation and a monovalent anion, such as XY₂, then we have ...

XY₂(s) <==> X²⁺(aq) + 2Y^-(aq)

Ksp = [X²⁺][Y^-]²

6.6x10^-6 = (s)(2s)² = 4s³

s = 1.2x10^-2 M = molar solubility

So, you can see the molar solubility will depend on the nature of the salt.