Write oxidation, reduction and addition reaction of methanal with hydrogen cyanide.

(1) Oxidation: Methanoic acid is formed by oxidation of methanal in presence of oxidising agent.

HCHO HCOOH

(2) Reduction: Methanol is prepared by reduction when methanal reacts with dihydrogen (H₂) gas in the presence of palladium catalyst.

HCHO + H₂CH₃OH

(3) Addition reaction of methanal with hydrogen cyanide- On addition of HCN to methanal then methanal cyanohydrin is formed.

H-CHO + H-CN H-CHOH-CN