What is the minimum concentration of sulfate ion, SO4 2- that must be present in a 0.050 M solution of Ca2+ to cause a precipitate to form? The K sp for calcium sulfate, CaSO4, is 7.10 × 10-5

[ ]minimum=1.42*M

Explanation:

Precipitate occurs only when the ionic product is greater than the solubility product.

I.e. Kip>Ksp  

And from above equation it is clearly that the minimum value of Kip is equal to Ksp

(aq)  = (aq)+ (aq);

Ksp=[][];

Hence Kip=Ksp; minimum value of Kip is equal to Ksp and this will give the minimum concentration of SO4-2 to precipitate the 0.050 M solution of Ca2+

Kip = [][]  = Ksp=7.10 × 10-5

[]  =Ksp/[] ;

[]=(7.10 × 10-5)/0.050;

[]minimum=1.42* M

i believe that it is a exoplanet

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.