162 grams
First, look up the atomic weight of all involved elements
Atomic weight Magnesium = 24.305
Atomic weight Chlorine = 35.453
Now, calculate the molar mass of MgCl2
24.305 + 2 * 35.453 = 95.211 g/mol
Finally, multiply the molar mass by the number of moles
95.211 g/mol * 1.70 mol = 161.8587 g
Rounding to 3 significant figures gives 162 grams.
