Question

What is the solubility product of calcium hydroxide?

Answer 1

The Ksp for calcium hydroxide is Ksp = `[Ca^(2+)][OH^-]^2`

You will need to use the dissociation equation to figure this out and apply the law of mass action.

`CaOH_2`(s) -> `Ca^(2+)` + 2`OH^-`

Solid substances are not included in writing an equilibrium expression. So you will only have the `Ca^(2+)` and the `OH^-` in the expression. The calcium ion has no exponent, the hydroxide ion must be squared because of the coefficient of 2.

The Ksp value for 4.68×10-6 for `CaOH_2` indicates that this is a moderately soluble compound.