The solubility of CaSO4 is 0.209 g/100 mL of water at 30 degrees celsius. if 0.500 g CaSO4 is stirred overnight at 30 Degrees Celsius with 100.0 mL of water,

Question

a. How many grams of CaSO4 remain undissolved?
b. Calculate the molarity of CaSO44 in solution

Answer 1

Solubility CaSO4 = grams/molar mass = mols in 100 mL.
Convert mols CaSO4 to g. g = mols x molar mass CaSO4.
a.
Total grams - grams dissolved = ?

b.
mols CaSO4 in 100 mL x (1000/100) = mols CaSO4 in 1 L and M = mols/L.