posted by Lauren .
If you had excess chlorine, how many moles of of aluminum chloride could be produced from 20.0 g of aluminum?
If you had excess aluminum, how many moles of aluminum chloride could be produced from 25.0 g of chlorine gas Cl2?
Here is a worked example that will take care of all of your stoichiometry problems. Just follow the steps. Post your work if you get stuck.