What is the mass of 4MgCl2?

To find the mass of 4 moles of magnesium chloride (MgCl2), you first need to calculate the molar mass of MgCl2. The molar mass is approximately 95.21 g/mol (24.31 g/mol for Mg and 35.45 g/mol for each Cl, with two Cl atoms). Thus, the mass of 4 moles of MgCl2 is calculated as 4 moles × 95.21 g/mol = 380.84 grams.