with chem lab (starts at 8 am today!!!). Added NaF to 3 separate solutions containing Ca2+, Mg(OH2)6 2+, and Al(OH2)6 3+. Found the calcium & magnesium precipitated and aluminum apparently did not. (so concluded CaF2 and MgF2 were much less soluble).
So the point of that, acc. to my lab, was to figure a method for testing Mg2+ in the presence of Al3+. The question is what ion would interfere with this test and why? And how can this interference be circumvented?