Balance these equations

18 Feb 2009

1. ___ Cu(s) + ___ O2(g) --> ___ CuO(s)

2. ___ H2O(l) --> ___ H2(g) + ___ O2(g)

3. ___ Fe(s) + ___ H2O(g) --> ___ H2(g) + ___ Fe3O4(s)

4. ___ Fe2O3(s) + ___ H2(g) --> ___ Fe(s) + ___ H2O(l)

5. ___ CaCO3(s) --> ___ CaO(s) + ___ CO2(g)