To calculate the molar mass of magnesium chloride MgCl2 , we need to find the molar mass of each element in the compound and then add them together.1. Find the molar mass of magnesium Mg :The molar mass of magnesium is 24.305 g/mol found on the periodic table .2. Find the molar mass of chlorine Cl :The molar mass of chlorine is 35.453 g/mol found on the periodic table .3. Calculate the molar mass of magnesium chloride MgCl2 :Since there is one magnesium atom and two chlorine atoms in the compound, we need to multiply the molar mass of chlorine by 2 and then add it to the molar mass of magnesium.Molar mass of MgCl2 = molar mass of Mg + 2 * molar mass of Cl Molar mass of MgCl2 = 24.305 g/mol + 2 * 35.453 g/molMolar mass of MgCl2 = 24.305 g/mol + 70.906 g/molMolar mass of MgCl2 = 95.211 g/molSo, the molar mass of magnesium chloride MgCl2 is 95.211 g/mol.