What is the mass of 3.90 moles of magnesium chloride

 find the molar mass of MgCl2 by adding the molar masses of its components then(24.305) + 2(35.453) = 95.211  MgCl2 then, use stoichiometry to determine the mass of 8.9 moles

First we have to find the Molar Mass of Magnesium Chloride (MgCl2)

Molar mass of
Mg-24.30
Cl-35.45x2 (we do times 2 because there are 2 Cl atoms)
Add the molar masses together, and you get 95.20

One mole=95.205g

And there are 3.90 moles so
95.205×3.90=371.28

3.90moles of MgCl2= 371.28g

Bthe s the