What is the maximum concentration of carbonate ions that will precipitate BaCO3 but not MgCO3 from a solution that is 4.2 × 10–3 M each in Mg2+ and Ba2+? For MgCO3, Ksp = 1.0 × 10–15 and for BaCO3, Ksp = 2.6 × 10–9.
A. 2.4 × 10–13 M
B. 6.2 × 10–7 M
C. 3.2 × 10–8 M
D. 5.1 × 10–5 M
E. None of these; MgCO3 will always precipitate before BaCO3.