The correct mathematical expression for finding the molar solubility (s) of sn (oh) 2 is:

Answer is: Ksp = 4s³.

Balanced chemical reaction (dissociation) of strontium hydroxide:

Sr (OH) ₂ (s) → Sr²⁺ (aq) + 2OH⁻ (aq).

Ksp (Sr (OH) ₂) = [Sr²⁺]·[OH⁻]².

[ Sr²⁺] = s.

[ OH⁻] = [Sr²⁺] = 2s

Ksp = (2s) ² · x = 4s³.

Ksp is the solubility product constant for a solid substance dissolving in an aqueous solution.

[ Sr²⁺] is equilibrium concentration of iumcations.

[ OH⁻] is equilibrium concentration of hydroxide anions.