Question

Primary and secondary nitroalkanes containing α – H atom show property of:
A. Chain Isomerism
B. Tautomerism
C. Optical isomerism
D. geometrical isomerism

Answer 1

Hint: Isomerism, the existence of molecules that have the same numbers of the same kinds of atoms (and hence the same formula) but differ in chemical and physical properties. The roots of the word ‘isomer’ are Greek - isos plus meros, or “equal parts.”

Complete Step by Step Solution:

A. Chain Isomerism:
Chain isomers are made up of two or more carbon or other compounds with the same molecular formula but different atomic arrangements, or branches. It is also known as skeletal isomerism. The components of these isomers display differently branched structures. Commonly, chain isomers differ in the branching of carbon.

B. Tautomerism:
Tautomerism is the ability of certain organic compounds to react in isomeric structure that differ from each other in the position of a hydrogen atom and double bond. Since, primary and secondary nitroalkanes differ from each other in the position of α-hydrogen atom, they show property of tautomerism.

C. Optical isomerism:
Compounds that exhibit optical isomerism feature similar bonds but different spatial arrangements of atoms forming non-superimposable mirror images. These optical isomers are also known as enantiomers. Enantiomers differ from each other in their optical activities. Dextro enantiomers rotate the plane of polarized light to the right whereas laevo enantiomers rotate it to the left.

D. geometrical isomerism:
Geometrical isomerism is popularly known as cis – trans isomerism. These isomers have different spatial arrangements of atom in three – dimensional space.
Hence, primary and secondary nitroalkanes containing α – H atom show property of tautomerism.

Hence, option B is correct answer.

Notes:
Always remember, Tautomerism is the ability of certain organic compounds to react in isomeric structure that differ from each other in the position of a hydrogen atom and double bond.
Enantiomers are chiral molecules that are mirror images of one another. The molecules are non-superimposable on one another. This means that the molecules cannot be placed on top of one another and give the same molecule.
Chiral molecules with one or more stereocenters can be enantiomers.