When formaldehyde and potassium hydroxide (KOH) are heated, we get methyl alcohol and potassium formate. This reaction is known as the Cannizzaro reaction. In Cannizzaro's reaction, one substance is oxidized and the other is reduced.
2HCHO+KOH → HCOOK+CH3OH.
Thus in this reaction, methyl alcohol (CH3OH) is produced. This reaction is known as Cannizaro's reaction