The oxidation of methanol (CH3OH) to methanal (HCHO) can be represented by the following chemical reaction:

CH3OH + [O] → HCHO + H2O

Where "[O]" represents an oxidizing agent, typically oxygen gas (O2) or a reagent like potassium permanganate (KMnO4) or chromic acid (H2CrO4).

Here's a breakdown of the reaction:

* Methanol (CH3OH): The reactant, a simple alcohol.

* Oxidizing agent ([O]): Provides the oxygen needed for the oxidation.

* Methanal (HCHO): The product, also known as formaldehyde, an aldehyde.

* Water (H2O): A byproduct of the reaction.

Note: This reaction usually requires a catalyst, such as a metal oxide or a silver catalyst, and is often conducted at elevated temperatures.