15.1 Exercise 31

Which of the following compounds precipitates from a solution that has the concentrations indicated? (See Appendix J for K_sp values.)

(a) CaCO₃: [Ca²⁺] = 0.003 M, $\left[\text{CO}_{\text{3}} ^{\text{2}−}\right]$ = 0.003 M

(b) Co(OH)₂: [Co²⁺] = 0.01 M, [OH^–] = 1 $\times$ 10^–7 M

(c) CaHPO₄: [Ca²⁺] = 0.01 M, $\left[\text{HPO}_{\text{4}} ^{\text{2}−}\right]$ = 2 $\times$ 10^–6 M

(d) Pb₃(PO₄)₂: [Pb²⁺] = 0.01 M, $\left[\text{PO}_{\text{4}} ^{\text{3}−}\right]$= 1 $\times$ 10^–13 M