Ncert Solutions Chemistry Class 12th

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Tert-butyl bromide is substituted via the S_N¹ process because it may produce a stable carbocation in the first step after the halide group is cleaved. The nucleophile OH -  interacts with the carbocation next. The primary halide n-butylbromide, on the other hand, is unable to create a stable carbocation, thus it undergoes the S_N² process, which is a one-step substitution involving OH -  attack and concomitant X -  leaving to generate n-butyl alcohol.

This is a short answer type question as classified in NCERT Exemplar

Because of resonance stabilisation, aryl halides are less reactive to nucleophilic substitution. The inclusion of a -NO₂, an electron-withdrawing group in the ortho or para position, enhances the aryl halide's sensitivity to substitution. The more electron withdrawing groups there are in the aryl halide, the more reactive it is. The decreasing sequence of reactivity, according to this theory, is III > II > I.

This is a short answer type question as classified in NCERT Exemplar

Nucleophilic substitution and elimination (β-elimination) reactions are both possible with alkyl halides.

Although, with the appropriate reaction conditions and reagent selection, a specific product can be produced. In most cases, the elimination reaction is best suited to strong and bigger bases, as well as high temperatures. The substitution reaction, on the other hand, is best for weaker and smaller bases at lower temperatures.

CH₃CH₂Br+alc.KOH KCH₂=CH₂ + HBr

CH₃CH₂Br + aqKOH→CH₃CH₂OH + KBr

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The IUPAC names for DDT and benzene hexachloride are 2, 2-bis (4-chlorophenyl)-1, 1-trichloroethane and 1, 2, 3, 4, 5, 6-hexachlorocyclohexane, respectively.

They are poisonous and non-bio digestible at the same time. They are fat soluble, and their concentration in the food chain continues to rise. As a result, they are prohibited in India and other nations.

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The S_N¹  mechanism advances through the production of carbocation. The breakage of the C-halogen bond occurs during this phase. The solution of the halide ions is done with the protons of the protic solvent as a result. In this approach, polar solvents aid in the ionisation process by solvating the ions and stabilising them.

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RMgX+H₂O→RH+Mg (OH)X

Because the Grignard reagents are very reactive in nature, even residues of moisture must be avoided. Even minute amounts of water can cause these reagents to generate hydrocarbons.

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In nature, allyl chloride becomes very reactive due to the production of carbocation, which is extremely stable due to resonance. Due to carbocation, there will be no such stability in the case of n-propyl chloride.

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Due to the resonance stabilisation of the benzyl ring, compound (B) would conduct the S_N¹ reaction faster than compound (A). The carbocation C₆H₅CH₂Cl⁺  is very stable when the -Cl from the ring is cleaved, and it is driven to carry out the S_N¹ reaction.