The following are actual student responses to the question: Why is it necessary to balance chemical equations?

a. The chemicals will not react until you have added the correct mole ratios.

b. The correct products will not be formed unless the right amount of reactants have been added.

c. A certain number of products cannot be formed without a certain number of reactants.

d. The balanced equation tells you how much reactant you need and allows you to predict how much product you’ll make.

e. A mole-to-mole ratio must be established for the reaction to occur as written.

Justify the best choice, and for choices you did not pick, explain what is wrong with them.