First you need to calculate the number of moles of aluminium and copper chloride.
number of moles = mass / molecular weight
moles of Al = 512 / 27 = 19 moles
moles of CuCl = 1147 / 99 = 11.6 moles
From the reaction you see that:
if 2 moles of Al will react with 3 moles of CuCl
then 19 moles of Al will react with X moles of CuCl
X = (19 × 3) / 2 = 28.5 moles of CuCl, way more that 11.6 moles of CuCl wich is the quantity you have. So the copper chloride is the limiting reagent.
