Label each pair of compounds as constitutional isomers, stereoisomers, or not isomers of each other.

Constitutional isomers are the structural isomers that have the molecular formula but differ from each other in terms of the connectivity between the various atoms.

Stereoisomers have the same order of bonding but differ from each other in terms of the three-dimensional arrangement of atoms in space.

a. The following pair of compounds are the stereoisomers of each other.

A

Trans Isomer

B

Cis isomer

The above compounds are trans and cis isomers of each other. In the case of compound A, one of the groups is at the top, and the other is at the bottom, which means it is a trans isomer.

In compound B, both the groups are at the top, i.e., on the same side, which means it is a cis isomer.

The above two compounds have the same molecular formula${\text{C}}_7{\text{H}}_{14}$. These two compounds differ in terms of the connectivity of the two methyl groups.

These two compounds have different molecular formulas.

They have different molecular formulas.