To find solubility, we need calculate how much potassium sulfate will be dissolved at 100 g of water.
12 g potassium sulfate ------ 75 g water
x g potassium sulfate --------100 g water
x=12*100/75 = 16g
So, solubility of potassium sulfate at 60⁰ C is 16 g potassium sulfate per 100 g of water.
