What is the value of q when the solution contains 2.00*10-2 m sr2 + and 1.50*10-3m cro42-?

Answer is: ion product for strontium chromate is 3·10⁻⁵.

Balanced chemical reaction (dissociation) of strontium chromate:

Sr²⁺ (aq) + CrO₄²⁻ (aq) → SrCrO₄.

Qsp (SrCrO₄) = c (Sr²⁺) · (CrO₄²⁻).

c (Sr²⁺) = 2.00·10⁻² M.

c (CrO₄²⁻) = 1.50·10⁻³ M.

Q = 2.00·10⁻² M · 1.50·10⁻³ M.

Q = 0.00003 = 3·10⁻⁵ M².