After heating, how many grams of the anhydrous compound remained

Question

A 52.2 gram sample of BeSO₄  4 H₂O was heated thoroughly in a porcelain crucible, until its weight remained constant

Answer 1

molar mass of H₂O = 18 g/mol

molar mass of BeSO₄.4H₂O = (9 + 32 + (16 * 4) + (4 * 18)) g/mol = 177 g/mol

molar mass of BeSO₄ = (9 + 32 + (16 * 4)) g/mol = 105 g/mol

moles = mass/molar mass = 52.2/177 = 0.295 mol

0.295 moles of BeSO₄.4H₂O is heated until all the water is gone and the salt becomes anhydrous(BeSO₄).

Mass of BeSO₄ = (0.295 mol * 105 g/mol) = 30.975 g