The limiting reagent is the reagent with the least amount of moles. Converting grams to moles, you should find that there is 4.11 mol Mg and 1.49 mol CuCl2. CuCl2 is the limiting reagent.
The limiting reagent is what you will use to determine how much product you have. By stoichiometry, you can see that for every mole of CuCl2, you have one mole of Cu. So, that means we have 1.49 mol Cu. Convert to grams. Your answer should be 94.7 g.
