The molar mass of magnesium sulfate MgSO4 can be calculated by adding the molar masses of its constituent elements:- Magnesium Mg : 24.305 g/mol- Sulfur S : 32.07 g/mol- Oxygen O : 16.00 g/molSince there is one magnesium atom, one sulfur atom, and four oxygen atoms in MgSO4, the molar mass can be calculated as follows:Molar mass of MgSO4 = 1 24.305 + 1 32.07 + 4 16.00 Molar mass of MgSO4 = 24.305 + 32.07 + 64.00Molar mass of MgSO4 = 120.375 g/molSo, the molar mass of magnesium sulfate MgSO4 is approximately 120.375 g/mol.