Răspuns:
2Cu + O2 -> 2CuO
2Ba + O2 -> 2BaO
2Fe + 3O2 -> Fe2O3
2Na + 2H2O = 2NaOH + H2
FeCl3 + 3NaOH ->3NaCl + Fe(OH)3
Mg+2HCl ->MgCl2 +H2
2Fe + 3S -> Fe2S3
Ca + 2AgNO3 -> Ca(NO3)2 + 2 Ag
2Al + 6HCl -> 2AlCl3 + 3H2
N2 +3 H2 -> 2NH3
H2SO4 + 2NaOH -> Na2SO4 + 2H2O.