Question

Assertion:Toluene on Friedel craft methylation gives o- and p-xylene
Reason: $C{{H}_{3}}$-group bonded to the benzene ring increases electron density at o- and p-position.
A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion.
B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion.
C. Assertion is correct but Reason is incorrect.
D. Both Assertion and Reason are incorrect.

Answer 1

Electrophilic aromatic substitution reactions are generally organic reactions in which an electrophile replaces an atom which is attached to an aromatic ring. These reactions involve the replacement of a hydrogen atom belonging to a benzene ring with an electrophile.

Complete answer:
There are many type of aromatic substitution out of which the most important electrophilic aromatic substitutions are aromatic nitration, aromatic halogenation, aromatic sulfonation, aromatic alkylation and aromatic acylation Friedel–Crafts reaction. The aromaticity of the aromatic system remains as such in an electrophilic aromatic substitution reaction.
In the given reaction when toluene undergo through the process of Friedel craft methylation then it gives both gives o- and p-xylene this can be explained as toluene has methyl group i.e. $C{{H}_{3}}$ group attached by itself through benzene ring this deactivates the benzene ring due to hyperconjugation effect which as a result increase the electron density at ortho and para position for the attack of electrophiles.

Hence we can say that option A is the correct answer.

Note:
By using inductive effects we can predict the acidity and basicity of compounds. It tells us about the electron withdrawing group and electron donating group. electron withdrawing groups increase the acidity of a compound while presence of electron donating groups decrease the basicity of the compound.