Magnesium carbonate, mgco3, has a ksp value of 6.80×10−6 . what happens when magnesium and carbonate solutions are mixed to give 2.50×10−3 m mg2+ and 2.00×10−3 m co32−?
when MgCO₃ dissolves it dissociates into the following ions MgCO₃ ---> Mg²⁺ + CO₃²⁻ reaction quotient (Q) = [Mg²⁺][CO₃²⁻] ksp is the solubility product constant. If the reaction quotient > ksp the ion will precipitate, however if Q< ksp the salt will not precipitate. First we need to calculate Q Q = (2.5 x 10⁻³ M)(2.0 x 10⁻³ M) Q = 5 x 10⁻⁶ ksp of salt is 6.8 x 10⁻⁶ however Q < ksp therefore salt will not precipitate.