(15) $C_2H_2+H_2O\xrightarrow{{HgSO_4, H_2SO_4, t^o}} CH_3CHO$
(16) $CH_3CHO+2AgNO_3+3NH_3+H_2O\to CH_3COONH_4+2Ag+2NH_4NO_3$
(19) $CH_4+\dfrac{1}{2}O_2\xrightarrow{{Cu, t^o}} CH_3OH$
(20) $CH_3OH+HCl\to CH_3Cl+H_2O$
(21) $CH_3OH+C_2H_5OH\xrightarrow{{H_2SO_4 đ, 140^oC}} CH_3OC_2H_5+H_2O$
(22) $HCHO+H_2\xrightarrow{{Ni, t^o}} CH_3OH$
(23) $CH_3OH+CuO\xrightarrow{{t^o}} HCHO+Cu+H_2O$
