Chemistry unit 7

A mixture contains free ions M2+ and N2+, initially each at 0.010 mol L-1. Addition of a soluble source of X- can precipitate MX2 or NX2. Their solubility products are Ksp(MX2)=1×10^-8 and Ksp(NX2)=1×10^-6, with Ksp=[metal ion][X-]^2. Treat volume change and complex formation as negligible. Added X- is adjusted slowly so solid and solution remain at equilibrium. Precipitation starts when the ion product reaches Ksp.