NEET2026ChemistryChapterActual
Formic acid (methanoic acid) exhibits certain unique and abnormal behaviors compared to other higher aliphatic carboxylic acids due to its specific structure. Which of the following statements regarding formic acid is INCORRECT?
Options
- AIt acts as a reducing agent and forms a silver mirror when treated with Tollens' reagent.
- BIt gives a brick-red precipitate of Cu₂O when heated with Fehling's solution.
- CIt readily undergoes the Hell-Volhard-Zelinsky (HVZ) reaction when treated with Cl₂ and red phosphorus.
- DIt rapidly dehydrates to yield carbon monoxide ( CO ) gas when heated with concentrated H₂SO₄ .
Correct answer
C. It readily undergoes the Hell-Volhard-Zelinsky (HVZ) reaction when treated with Cl₂ and red phosphorus.
Step-by-step solution
Formic acid ( H-COOH ) possesses a unique structure containing both an aldehydic group and a carboxylic acid group. Due to the presence of the aldehydic moiety, it acts as a reducing agent. It reduces Tollens' reagent to form a silver mirror and Fehling's solution to form a brick-red precipitate of Cu₂O . Thus, statements (1) and (2) are correct. Heating formic acid with concentrated H₂SO₄ leads to its dehydration, producing carbon monoxide ( CO ) gas and water. Thus, statement (4) is correct. The Hell-Volhard-Zeli