Question

Ethyl alcohol containing $9.5%$ methyl alcohol land $0.5%$ pyridine is called as:
(a) spirit
(b) denatured spirit
(c) rectified spirit
(d) absolute alcohol

Answer 1

Hint: Ethanol is very harmful and dangerous for the health if it is taken in excess and so, thus, it is made to undergoes a process in which there is breaking of the hydrogen bonds known as the denaturation and after denaturation it has random structure and is made poisonous by adding substances like methanol, pyridine etc. Now answer the statement.

Complete answer:
First of all, let’s discuss alcohol. Alcohols are the compounds which contain the hydroxyl group(-OH) group attached to the alkyl group and are therefore regarded as the hydroxyl derivatives of hydrocarbons. They are also called aliphatic alcohols. Example: methyl alcohol, ethyl alcohol etc.
The methyl alcohol has the chemical formula as $\text{C}{{\text{H}}_{3}}\text{OH}$ and its IUPAC name is methanol and the ethyl alcohol has the chemical formula as ${{\text{C}}_{2}}{{\text{H}}_{5}}\text{OH}$ and its IUPAC name is ethanol and both of these are called as monohydric alcohols because they consists of one -OH group.
On the other hand, pyridine is an heterocyclic compound and in this one methyl group of the benzene ring is replaced with the nitrogen atom.
Now considering the statement ;
Ethyl alcohol which contains methyl alcohol and pyridine is called the denatured spirit. When ethyl alcohol i.e. the ethanol is denatured ( i.e. the process of breaking of the hydrogen bonds within the molecules ) and mixed with other substances like the methanol and pyridine, it is then known as the denatured spirit and is poisonous , bad tasting and foul-smelling in nature.
So, ethyl alcohol containing $9.5%$ methyl alcohol land $0.5%$ pyridine is called a denatured spirit.

Hence, option (b) is correct.

Note: Ethanol is denatured because it is dangerous when taken in excess and so to prevent its consumption it is denatured by adding poisonous substances into it to inhibit and discourage people from drinking it.