Question

Which of the following is tertiary alcohol?
A) Ethyl alcohol
B) Isopropyl alcohol
C) Neopentyl alcohol
D) $2-$ methyl $2-$propanol

Answer 1

Hint:Alcohol is defined as an organic compound that consists of one or more hydroxyl groups, that is attached to carbon atom of an alkyl group. For example, ethyl alcohol, isopropyl alcohol, neopentyl alcohol.


Complete step by step solution:
In this question, all the options present are alcohols.
There are three types of alcohol:
a) Primary alcohol: In this alcohol, the hydroxyl group is attached to a carbon atom, that is attached to only one alkyl group. For example, methanol and ethanol.
b) Secondary alcohol: In this alcohol, the hydroxyl group is attached to a carbon atom, that is attached to two alkyl groups. For example, butan$-2-$ol, propan$-2-$ol.
c) Tertiary alcohol: In this alcohol, the hydroxyl group is attached to a carbon atom, that is attached to three alkyl groups. For example, $2-$methylbutan$-2-$ol.
Let us discuss the above options given in this question, one by one and find out which one is tertiary alcohol.
1) Ethyl alcohol is a primary alcohol because the hydroxyl group is attached to the carbon, that is attached to only one alkyl group. Therefore, this option is incorrect.
2) Isopropyl is a secondary alcohol as the hydroxyl group is attached to a carbon atom, that is attached to two alkyl groups. Therefore, this option is also incorrect.
3) Neopentyl alcohol is a primary alcohol because the hydroxyl group is attached to the carbon, that is attached to only one alkyl group. Therefore, this option is also incorrect.
$2-$ methyl $2-$propanol is a tertiary alcohol as the hydroxyl group is attached to a carbon atom, that is attached to three alkyl groups. Therefore, this option is correct.

Hence, the correct option is (D) $2-$ methyl $2-$propanol.


Note:Alcohols are considered as derivatives of water in which one hydrogen is removed with one alkyl group.Alcohols are used as an anti-freezing agent with a mix of a solution of ethylene glycol dissolved in water.Some alcohols are used as fuels, preservatives, antiseptic agents.