Question

Ethanol is denatured (made unfit for human consumption) by adding a poisonous substance. Identify it.
(A) Tartaric acid
(B) Methyl alcohol
(C) Acetic acid
(D) Stearic acid

Answer 1

Hint: The compound is also called wood alcohol. The compound added as a denaturation agent only changes the few properties of ethanol.

Complete answer:
- So in the question it is asked which of the poisonous substances is used for denaturation of ethanol.
- We are very familiar with the term ethanol which is commonly called as alcohol .Ethanol is an organic alcohol, which is commonly used in beverages and also finds many industrial applications.
- So here it is asked about the denaturation of the ethanol. The denaturation of ethanol generally refers to mixing a poisonous substance with the ethanol so that the ethanol will be made unfit for consumption. These toxic substances added are called as the denaturant. The generally used denaturation is methyl alcohol or pyridine. The role of a denaturant is only to alter its chemical property rather than forming a new compound. When the denaturant is added to the ethanol, it will possess an unpleasant smell and taste which will prevent its consumption. Sometimes dyes are also mixed with them so that we could differentiate visibility.
- So we know that, from the above options given, the correct answer for the question is option (B).
Since the methyl alcohol is commonly used as the denaturant for the denaturation process of ethanol, the denatured ethanol is also called as the methylated spirits.

Additional Information :
The denatured ethanol is used found in sanitizers, rubbing alcohol, cosmetics etc. However, the methylated spirits i.e. the ethanol which is denatured using the methanol is not found in the compounds which are applied in the skin since the methanol is toxic and is absorbed by the skin.

Note:
> Other denaturants that are us include diethyl phthalate, benzene etc. The additives that are used with methyl alcohol are acetone, methyl isobutyl ketone and ethyl methyl ketone.
> Pyridine is another denaturant which is commonly used which adds a fishy odor for ethanol.