Question

How many positional isomers are there in ${\mathrm{C}}_5{\mathrm{H}}_{11}\mathrm{Br}$?

Answer 1

Position isomerism:

1. The compounds which have the same molecular formula, but different structural formulas i.e. they differ in the position of the attachment of the functional group are position isomers of each other.
2. They are the same carbon skeleton constitutional isomers.

Position isomerism in ${\mathrm{C}}_5{\mathrm{H}}_{11}\mathrm{Br}$:

1. In the case of ${\mathrm{C}}_5{\mathrm{H}}_{11}\mathrm{Br}$, there are three position isomers namely, $1-$Bromopentane, $2-$Bromopentane, and $3-$Bromopentane.
2. In $1-$Bromopentane, the Bromine is attached to the first Carbon atom of the Pentane chain.
3. In $2-$Bromopentane, the Bromine is attached to the second Carbon atom of the Pentane chain.
4. In $3-$Bromopentane, the Bromine is attached to the third Carbon atom of the Pentane chain.

Hence, there are three positional isomers that are possible for ${\mathrm{C}}_5{\mathrm{H}}_{11}\mathrm{Br}$.