Question

Molecules of 1-bromopropane and 2-bromopropane differ in

Answer 1

Molecules of 1-bromopropane and 2-bromopropane differ in(1) molecular formula.

Answer 2

Answer: (2) structural formula

Explanation:-

The compounds having similar molecular formula but different arrangement of atoms or groups in space are called isomers and the phenomenon is called as isomerism.  

1-bromopropane and 2-bromopropane are position isomers which have same molecular formula but different position of the functional groups attached.

The chemical formula for both the compounds 1-bromopropane and 2-bromopropane is $CH_3CH_2CH_2Br$. Thus both have same molecular formula , 3 carbon atoms per molecule and 1 bromine atom per molecule.