Balancing chemical equations requires ensuring that the number of atoms on both sides of the equation is the same. In combustion and respiration reactions, oxygen is crucial, and the products are often carbon dioxide and water.
When steam is passed over red-hot iron, iron reacts with water vapor to form iron oxide and hydrogen gas. The balanced chemical equation for this reaction is:
\[
3Fe (s) + 4H_2O (g) \rightarrow Fe_3O_4 (s) + 4H_2 (g)
\]
In this reaction, iron (Fe) reacts with steam (water vapor, H2O) to form iron oxide (Fe3O4) and hydrogen gas (H2).