In order to find the number of moles in a given mass of any compound, we need to use the molar mass of this compound, which is the total mass present in 1 mol of the compound. The molar mass of CaSO4 is 136.14g/mol
136.14 grams = 1 mol of CaSO4
37.16 grams = x moles of CaSO4
136.14x = 37.16
x = 37.16/136.14
x = 0.27 moles of CaSO4
In 37.16 grams, we will have 0.27 moles of CaSO4