Base your answers to questions 72 through 74 on the information below.
Iron has been used for thousands of years. In the air, iron corrodes. One reaction for the corrosion of iron is represented by the balanced equation below.
In the presence of water, iron corrodes more quickly. This corrosion is represented by the unbalanced equation below.
74 Balance the equation in 'Jour answer booklet, using the smallest whole-number coefficients.