Question

Which one of the following is an optically active compound?

• A. n-propanol
• B. 2-chlorobutane
• C. n-butanol
• D. 4-hydroxyheptane

Answer 1

The correct option is B 2-chlorobutane

In (b) i.e. 2-Chlorobutane, chiral carbon atom is present so it is optical active. A chiral centre in an organic compound is a carbon atom directly connected to four different groups. Chiral compounds with one chiral centre are always optically active.
Except b, all other have no chiral carbon thus they are not optically active.