Which of the following reagents, are used for denaturation of alcohol?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → \(CuSO_4\) and pyridine
Ethanol for industrial use is taxed far less than drinking alcohol, so it is made unfit for drinking before it is sold. This is called denaturation of alcohol. Two substances are added: copper sulphate, which gives the alcohol a blue colour, and pyridine, a foul-smelling liquid that makes it unpleasant to drink. Neither stops the alcohol from being used as a solvent or fuel.
NCERT (2026-27 edition):
Ethanol – “… The commercial alcohol is made unfit for drinking by mixing in it some copper sulphate (to give it a colour) and pyridine (a foul smelling liquid). It is known as denaturation of alcohol.”
Note: The same/similar question has been asked in different years by NTA as per the details given below:
| 2026 | 2025 | 2024 | 2023 | 2022 |
|---|---|---|---|---|
| – | – | – | 10-06 S3 07-06 S3 | – |