Question

A mass of 5.4g of aluminum is reacted with excess copper(II) chloride as shown in the reaction in the image. How much copper can be produced by this reaction?

3 CuCl2 + Al ---> 2 AlCl3 + 3 Cu

Answer 1

Mass of copper produced is 19.07g

Answer 2

Your equation is not balanced. The correct balanced equation is as follows:
3 CuCl2 + 2Al ---> 2 AlCl3 + 3 Cu
mols Al = grams/atomic mass = 5.4/27 = 0.2
Convert to mols Cu produced this way.
0.2 mols Al x (3 mols Cu/2 mols Al) = 0.2 x 3/2 = 0.3 mols Cu.
Then grams Cu = mols Cu x atomic mass Cu = 0.3 x 63.54 = 19 g Cu to two significant figures.