The empirical formula is CaCl2, which means Ca= x & Cl= 2x & where the molecular weight is 330 g
So x(Ca) + 2x(Cl) = 330 and when the molecular weight of Ca=40 & the molecular weight of Cl = 35
∴ x(40) + 2x (35) =330
40 x + 70 x = 330
110 x = 330
x= 330/110 = 3
∴ the molecular formula is Ca3Cl6