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Hydrocarbons

Short Answer Type

231. What happens when:
Toluene is heated with concentrated sulphuric acid.

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232. What happens when:
p-xylene is heated with alkaline KMnO₄.

300 Views

233.

What happens when:
Benzene is treated with n-propyl chloride in the presence of anhydrous AlCl₃.

532 Views

Long Answer Type

234.

Discuss the mechanism of electrophilic substitution reactions of benzene?

869 Views

235. Discuss the mechanism of chlorination of benzene.

341 Views

236.
How is benzene converted to nitrobenzene? Give mechanism.

When benzene is heated with a nitrating mixture (concentrated HNO₃ + conc. H2SO4) to about 330K, nitrobenzene is produced.

Mechanism: Different steps involved in the mechanism are:
(i) Generation of nitronium ion (electrophile):

(ii) Formation of carbocation: The electrophile attacks the benzene ring to form an intermediate carbocation which is resonance stabilised. It is a slow step.

The resonance hybrid of the above resonating structures can be represented as,

(iii) Proton transfer from the carbocation to yield nitrobenzene.

161 Views

237.

How benzene is converted into benzene sulphonic acid? Give its mechanism.
Or
Explain the mechanism of sulphonation of benzene.

524 Views

238.

Discuss the mechanism of Friedel Craft’s reaction.
Or
Discuss the mechanism of Friedel Craft’s alkylation of benzene. Give the mechanism of reaction of benzene within the presence of AlCl_3.Or

How is benzene converted into aceto-phenone? Name the reaction and discuss the mechanism explaining each step.

Or

Give the mechanism of acylation of benzene.