The ksp of zinc carbonate (znco3 is 1.0 × 10–10. what is the solubility concentration of carbonate ions in a saturated solution at 25°c? 1.4 × 10–5m 7.1 × 10–6m 1.7 × 10–5m 1.0 × 10–5m

Ksp - solubility product constant is equivalent to equilibrium constant, except this constant is used to determine the solubility of ions of a solid in a solution. 
ksp is the product of the soluble ions in the compound. Higher the ksp value, higher the degree of solubility.
ZnCO₃ (s) ---> Zn²⁺ (aq) +  CO₃²⁻ (aq)
                         n            n
ksp = [Zn²⁺][CO₃²⁻]
In the equation equal amounts of ions Zn²⁺ and CO₃²⁻ ions are soluble. 
amount of ions soluble = n
ksp is therefore equal to;
ksp = n x n
ksp = n²
ksp = 1 * 10⁻¹⁰ M
therefore 
1 * 10⁻¹⁰ M = n²
n = 1 x 10⁻⁵ M
therefore concentration of CO₃²⁻ = 1 x 10⁻⁵ M

They carry out the exchange of gases as we breathe ( oxygen and carbon dioxide).