Chemistry : Haloalkanes and Haloarenes

Presence of a nitro group in a benzene ring -

• activates the ring towards electrophilic substitution

• renders the ring basic

• deactivates the ring towards nucleophilic substitution

• deactivates the ring towards nucleophilic substitution

Which of the following is the correct order of decreasing S_N2 reactivity? 

• RCH₂X > R₃CX > R₂CHX

• RCH₂X > R₂CHX > R₃CX

• R₃CX > R₂CHX >RCH₂X

• R₃CX > R₂CHX >RCH₂X

The IUPAC name of 

• 1, 1-diethyl-2-dimethylpentane

• 4, 4-dimethyl-5, 5-diethylpentane

• 5, 5-diethyl-4, 4-dimethylpentane

• 5, 5-diethyl-4, 4-dimethylpentane

HBr reacts with CH₂ = CH – OCH₃ under anhydrous conditions at room temperature to give 

• CH₃CHO and CH₃Br

• BrCH₂CHO and CH₃OH

• BrCH₂ – CH₂ – OCH₃

• H₃C – CHBr – OCH₃

The IUPAC name of the compound shown below is

• 2-bromo-6-chlorocyclohex-1-ene

• 6-bromo-2-chlorocyclohexene

• 3-bromo-1-chlorocyclohexene

• 3-bromo-1-chlorocyclohexene

Phenyl magnesium bromide reacts with methanol to give

• a mixture of anisole and Mg(OH)Br

• a mixture of benzene and Mg(OMe)Br

• a mixture of toluene and Mg(OH)Br

• a mixture of toluene and Mg(OH)Br

The structure of the major product formed in the following reaction

Reaction of trans-2-phenyl-1-bromocyclopentane on reaction with alcoholic KOH produces 

• 4-phenylcyclopentene

• 2-phenylcyclopentene

• 1-phenylcyclopentene

• 1-phenylcyclopentene

2 methylbutane on reacting with bromine in the presence of sunlight gives mainly

• 1 – bromo -2 - methylbutane

• 2 – bromo -2 - methylbutane

• 2 – bromo -3 - methylbutane

• 2 – bromo -3 - methylbutane

Tertiary alkyl halides are practically inert to substitution by S_N2 mechanism because of

• insolubility

• instability

• inductive effect

• inductive effect