Write the reaction equation: Methane⇒Cloromethane⇒Methanol⇒Formaldehyde⇒Methanol.

Let us write down the reaction equations for organic compounds:
CH4 + Cl2 = CH3Cl + HCl – substitution reaction, occurs under strong illumination, methane chloride is formed;
CH3Cl + KOH = CH3OH + KCl – exchange, methanol was obtained;
CH3OH + CuO = CH2O + Cu + H2O – alcohol oxidation, formaldehyde was released;
CH2O + H2 = CH3OH – reduction of aldehyde, methanol was obtained.
Reaction products are of practical importance. Methane chloride is used as a solvent, formaldehyde is the basis in the production of phenol-formaldehyde plastics, and methanol is used as a fuel.