Ответ:

K+O2=KO2

4Fe+3O2=2Fe2O3

2Cu+O2=2CuO

2Na+2H2O=2NaOH+H2

Zn+H2O=ZnO+H2

Hg+H2O≠

2Na+H2SO4=Na2SO4+H2

Zn+H2SO4=ZnSO4+H2

Hg+HCl≠

Ca+CuSO4=CaSO4+Cu

Zn+2AgNO3=Zn(NO3)2+2Ag

Cu+FeCl3≠

Ba+Cl2=BaCl2

Hg+S=HgS

6Li+N2=2Li3N