Aluminum reacts with chlorine gas according to the following equation: 2Al(s) + 3Cl2(8)—2A1C13(s)
(a) What is the mole ratio of Cl2 to Al?
(b) How many moles of Cl2 are required to react with each mole of Al?
(c) How many moles of Cl2 are required to react with 0.085 mol of Al?

a) Cl₂: Al= 3: 2

b) 1.5 moles

c) 0.128 moles (3 s.f.)

Explanation:

a) Mole ratio can be determined by looking at the coefficients of the molecule in a balanced equation. The chemical equation given has already been balanced since the number of atoms of each element is the same on both sides. The coefficient of Cl₂ is 3 while that of Al is 2.

b) From the mole ratio, 2 moles of Al requires 3 moles of Cl₂. Thus for 1 mole of Al, number of moles of Cl₂ required= 3 ÷2= 1.5 moles

c) 1 mol of Al 1.5 moles of Cl₂

0.085 moles of Al 1.5(0.085)= 0.1275 moles of Cl₂