Question

Which of the following molecule is chiral in nature?

• A. Propan-2-ol
• B. Butan-2-ol
• C. 1-Bromobutane
• D. 2-Bromopropane

Hint:

Chirality rule: Look for a carbon with four different substituents. If any two groups are identical, the molecule is achiral.

Answer 1

The Correct Option is B

Concept: A molecule is chiral if it contains a carbon atom bonded to four different groups (asymmetric carbon). Such molecules are non-superimposable on their mirror images.
Step 1: Check each option for asymmetric carbon.
Option (A): Propan-2-ol Central carbon is attached to: CH$_3$, CH$_3$, OH, H Two identical groups present → Achiral.
Option (B): Butan-2-ol Second carbon is attached to: CH$_3$, C$_2$H$_5$, OH, H All four groups are different → Chiral.
Option (C): 1-Bromobutane Terminal carbon bonded to Br has two hydrogens → Not asymmetric → Achiral.
Option (D): 2-Bromopropane Central carbon attached to two CH$_3$ groups → Achiral.