Calculate the largest amount of AlCl3 that could be produced.

Question

Solid aluminum Al and chlorine Cl2 gas react to form solid aluminum chloride AlCl3. Suppose you have 7.0 mol of Al and 2.0 mol of Cl2 in a reactor.Calculate the largest amount of AlCl3 that could be produced. Round your answer to the nearest 0.1 mol.

Answer 1

Write the correctly balanced equation:

2Al(s) + 3Cl₂(g) ===> 2AlCl₃(s) ... balanced equation

Whenever you are given the amounts of BOTH reactants, you must first find which one, if either, is limiting.

moles Al = 7.0

moles Cl₂ = 2.0

Mole ratio in balanced equation is 2 : 3 for Al : Cl₂, so you need 1.5 times as much Cl₂ as you have Al. This is NOT the case here, so Cl₂ is limiting, and it alone will determine the amount of product formed.

The question asks for amount of AlCl₃ (in moles), so we just use dimensional analysis and the stoichiometry to find the answer:

2.0 mol Cl₂ x 2 mol AlCl₃ / 3 mol Cl₂ = 1.3 mol of AlCl₃ will be formed