Câu 1:
2Cu+O2$\xrightarrow{t^o} $2CuO
S+O2$\xrightarrow{t^o} $SO2
4P+5O2$\xrightarrow{t^o} $2P2O5
2Mg+O2$\xrightarrow{t^o} $2MgO
Câu 2:
CuO+H2$\xrightarrow{t^o} $Cu↓+H2O
Fe3O4+4H2$\xrightarrow{t^o} $3Fe↓+4H2O
Câu 3:
2Na+2H2O→2NaOH+H2↑
CaO+H2O→Ca(OH)2
SO3+H2O→H2SO4
--------------------Nguyễn Hoạt---------------------