What are the consequences of purposely having an excess of one of the reactants?

When one reactant is in excess, there will always be some left over. The other reactant becomes a limiting factor and controls how much of each product is produced. While using excess reactants can help to increase percentage yields, this is at the expense of atom economy.

Explanation:

the answer is b & c i believe : )

fe 55.85 g/mol and h2o 18.02 g/mol.