posted by tomi .
A 75.0mL sample of 1.56×10−2M Na2SO4(aq) is added to 75.0mL of 1.22×10−2M of Ca(NO3)2(aq).
What percentage of the Ca+ remains unprecipitated?
CaSO4(s) ==> Ca^+2 + SO4^=
Ksp = (Ca^+2)(SO4^=)
I would calculate moles Ca^+2 and moles SO4^=, from an ICE chart you will know which is the limiting reagent and from there which is the common ion (that will be the one in excess). Then calculate the solubility and from there how much remains. Find percent of that.
the answer is not clear