Explain what a limiting reactant is and why it is important in stoichiomerty?

It determines the maximum amount of the product that can be formed

Explanation:

Usually when performing a chemical reaction, it is hard to measure the exact amounts of the two reactants to react completely. This is why generally we take one reactant as our limiting reagent and another reagent in excess.

The reactant that is limiting reacts completely, while the reactant in excess still remains in a solution after reaction is over.

The importance of the limiting reactant is huge: it determines the maximum amount of the product that can be formed. It's limiting and, therefore, the extent of the reaction depends on how much of the limiting reagent we have. According to stoichiometry, we find the moles of a product formed directly from the limiting reagent, while the reagent in excess doesn't provide any relevant information.

a corroding iron, if that's one of your choices