Balance the chemical equations
1. Fe + H2 → Fe3O4 + H2 .
2. CH4 + O2 → CO2 + H2O
Balance the following chemical equation.
Na + O2 → Na2O
Ca + N2 → Ca3N2
N2 + H2 →NH3 CaCO3 +HCl → CaCl2 + CO2 +H2O