1. Formic acid is unique since it contains a hydrogen atom instead of an alkyl group.
2. It is regarded both as an aldehyde as well as a carboxylic acid.
3. Formic acid acts as reducing agent.
HCOOH + [O]→ CO2 + H2O
Like aldehydes, it reduces :-
a) Fehling’s solution to red precipitate
b) Tollen’s reagent to silver mirror
c) Decolourizes acidified KMnO4 solution
d) Turns K2Cr2O7 solution green
e) Reduces mercuric salts to mercurous salts
