Question

When two different 3D arrangements in space of the atoms in a molecule are interconvertible by free rotation about the single bonds, they are called:

• A. Ring chain isomers
• B. Conformational isomers
• C. Functional isomers
• D. All of the above

Answer 1

The correct option is B Conformational isomers

Theory :

When two different 3D arrangements in space of the atoms in a molecule are interconvertible by free rotation about the single bonds, they are called conformational isomers.
In conformational isomerism :
The basic structure of the molecule and various bond lengths and bond angles remain the same in all the arrangements or conformations.
Conformational isomers are not true isomers because energy difference between conformational isomers is very less. Hence, they are rapidly interconvertible and non-separable (cannot be isolated).