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Q.
Optical isomerism is shown by
Rajasthan PMTRajasthan PMT 2007Haloalkanes and Haloarenes
Solution:
Optical isomerism is shown by an asymmetric carbon atom which has a carbon atom attached to four different atoms or groups. So, butanol-$2$ is optically active.
$\underset{\text{butanol-2}}{H_3C-CH_2-\underset{\overset{|}{O}H}{\overset{\underset{|}{H}}{C}}-CH_3}$