Answer is: solubility of cadmium carbonate is 0,00017 g/L.
Cadmium carbonate in water: CdCO₃ → Cd²⁺ + CO₃²⁻.
[Cd²⁺] = [CO₃²⁻] = x.
Ksp = [Cd²⁺] · [CO₃²⁻].
10⁻¹² = x².
x= √10⁻¹².
x = [Cd²⁺] = [CO₃²⁻] = 10⁻⁶ mol/L.
[CdCO₃] = 10⁻⁶ mol/L.
n(CdCO₃) = 10⁻⁶ mol/L · 1 L = 10⁻⁶ mol.
m(CdCO₃) = n(CdCO₃) · M(CdCO₃).
m(CdCO₃) = 10⁻⁶ mol · 172,41 g/mol.
m(CdCO₃) = 0,00017 g/L.
