What is the total number of structural isomers possible for the compound with molecular formula $C_4H_9Br$?

4

The correct answer is Option (2) → 4

For the molecular formula C₄H₉Br (butyl bromides), the possible structural isomers are:

1. 1-Bromobutane (n-butyl bromide)
2. 2-Bromobutane (sec-butyl bromide)
3. 1-Bromo-2-methylpropane (isobutyl bromide)
4. 2-Bromo-2-methylpropane (tert-butyl bromide)

So, the total number of structural isomers is 4.