A solution is initially supersaturated with Ca2+ and CO32- ions by rapid addition of calcium carbonate, such that the concentrations of each are 2.10x10-3M. The water's pH is held at 8.5. When equilibrium is finally reached, determine:
(a) The concentration of free Ca2+ in the water
(b) The concentration of CO2(aq) in the water
(c) The mass of CaCO3(s) per litre of water.