Aluminum metal reacts with chlorine gas to form solid aluminum trichloride. what mass of chlorine gas is required to react completely with 163 g of aluminum?

Answer is: mass of chlorine gas is 642.04 grams.

Chemical reaction: 2Al + 3Cl₂ → 2AlCl₃.

m (Al) = 163 g.

n (Al) = m (Al) : M (Al).

n (Al) = 163 g : 27 g/mol.

n (Al) = 6.04 mol.

From chemical reaction: n (Al) : n (Cl₂) = 2 : 3.

n (Cl₂) = 6.04 mol · 3 : 2.

n (Cl₂) = 9.055 mol.

m (Cl₂) = n (Cl₂) · M (Cl₂).

m (Cl₂) = 9.055 mol · 70.90 g/mol.

m (Cl₂) = 642.04 g.