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

- decrease the number of plants and animals living in the water.

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).