Constitutional Isomers are molecules that have the same molecular formula (same number of atoms of each element) but different structure (connection of atoms).
Therefore, when we name the two molecules, they will have different names if they are constitutional isomers.
Example of constitutional isomers are butane (CH3CH2CH2CH3) and 2-methylpropane ((CH3)3CH. While both of these molecules have the molecular formula of C4H10, their connection is different leading to a different name.
Indicate whether the compounds in each set are constitutional isomers.
How to draw alkane constitutional isomers: