Question

ASSERTION: The second substituent may enter the mono-substituted benzene ring at either ortho, para or at meta position.
REASON: The position of the incoming group is determined by the nature of the group present in the monosubstituted benzene ring.

A.Both assertion and reason are correct and reason is the correct explanation of assertion.
B.Both assertion and reason are correct but reason is not the correct explanation of assertion.
C.Assertion is correct but reason is not correct
D.Both assertion and reason are incorrect

Answer 1

Hint: Ortho position: In benzene ring when two groups or atoms are at position $1,2$ i.e. at adjacent positions, are known as ortho position.
Meta-position: In benzene rings when two or more groups or atoms are alternate to each other i.e. $1,3$ or $1,5$ positions, is known as meta-position.
Para-position: In a benzene ring when two or more groups or atoms are at opposite positions i.e. $1,6$ is known as para-position.

Complete step by step solution:
First of all we will discuss different positions in benzene.
Ortho position: In a benzene ring when two groups or atoms are at position $1,2$ i.e. at adjacent positions, are known as ortho position. For example: if groups are nitro groups and they placed at position $1,2$ then they are said to be ortho nitro benzene.
Meta-position: In benzene rings when two or more groups or atoms are alternate to each other i.e. $1,3$ or $1,5$ positions, is known as meta-position. For example: if groups are nitro and they are placed at $1,3$ or $1,5$ positions then they are said to be meta nitro benzene.
Para-position: In a benzene ring when two or more groups or atoms are at opposite positions i.e. $1,6$ is known as para-position. For example: if groups are nitro and they are placed at $1,6$ positions then they are said to be para nitro benzene.
EWG ( electron-withdrawing group ) on benzene creates more electron density at the meta position and less electron density at ortho and para position. For example: carboxylic acid group, cyanide group. When these groups are attached to the benzene ring then the second group will come on meta position.
EDG(electron donating group) on benzene increases electron density at ortho and para position. For example: alcohol group and amine group. When these groups are attached to the benzene ring then the second group will come on ortho and para position.
Hence, the position (i.e. either ortho, para or at meta position) of the incoming group is determined by the nature of the group present in the monosubstituted benzene ring.

So option A is right i.e. both assertion and reason are correct and reason is the correct explanation of assertion.

Note:
Nitration: It is defined as the reaction in which the product formed will be a nitro compound i.e. nitro group will be present in that compound.
Nitrobenzene: It is the benzene ring in which one hydrogen of the benzene ring is replaced by nitro group.