Question

The number of optically active isomers of $C_4{H}_{9}Br$ is__________

Answer 1

Answer: 2

The isomers of the compound having formula $C_4{H}_{9}Br$ are shown below. Among the above compounds, only the second compound shown is chiral. Hence, it has two optical isomers.
There are four structural isomers all together, two straight chain and two branched chain. Among them, $2$-Bromobutane is chiral and exists in the form of two enantiomers.
$C_4{H}_{9}Br$


$(C{H}_3{)}_{3}C-Br$

$\ast$ represents chiral carbon