Formic acid ( HCOOH ), because of the presence of -CHO group (aldehydic group) reduces Tollen's reagent, Fehling solution etc. Thus, formic acid has reducing property.

There are several fatty acids, but the one that shows reducing property is Formic acid. Below is an explanation of why Formic acid exhibits reducing property.
- Formic Acid as a Reducing Agent:
Formic acid (HCOOH) is a weak acid that can act as a reducing agent in certain reactions. It has the ability to donate electrons or hydrogen atoms to another substance, thereby reducing it.
- Reducing Property of Formic Acid:
Formic acid can reduce other compounds by donating hydrogen atoms or electrons. This property is due to the presence of the formyl group (-CHO) in its structure, which can easily undergo redox reactions.
- Reaction Example:
One example of formic acid acting as a reducing agent is its reaction with potassium permanganate (KMnO4). In this reaction, formic acid reduces the purple KMnO4 to colorless Mn2+ ions.
- Overall Reaction:
HCOOH + 2KMnO4 → HCOOK + 2MnO2 + 2H2O + O2
- Importance of Reducing Property:
The reducing property of formic acid makes it useful in various chemical reactions, including organic synthesis, industrial processes, and in the pharmaceutical industry.
In conclusion, formic acid is a fatty acid that exhibits reducing property due to its ability to donate hydrogen atoms or electrons in reactions. This property makes it valuable in various chemical processes and applications.