a) $2Cu+O_2\buildrel{{t^o}}\over\longrightarrow 2CuO$
b) $2FeS_2+\dfrac{11}{2}O_2\buildrel{{t^o}}\over\longrightarrow Fe_2O_3+4SO_2$
c) $2SO_2+O_2⇄2SO_3$ $(t^o,V_2O_5)$
d) $H_2S+\dfrac{3}{2}O_2(dư)\buildrel{{t^o}}\over\longrightarrow SO_2+H_2O$
$H_2S+\dfrac{1}{2}O_2(thiếu)\buildrel{{t^o}}\over\longrightarrow S+H_2O$