Answer: 5.62 x 10⁻³ M
Step-by-step explanation:
1) Equilibrium equation:
Ca(IO₃)₂ ⇄ Ca⁺² + 2 IO⁻³
2) By stoichimetry ratio, the concentrtion of IO⁻³ ions is the double than the concentraion of Ca⁺² , so call them x and 2x.
3) Solubility product constant,Ksp:
Ksp = [Ca⁺²] [IO⁻³]² = x(2x)² = 4x³
=> 4x³ = 7.1 x 10⁻⁷
=> x^3 = 1.775 x 10⁻⁷
=> x = 5.62 x 10⁻³ M