Haloalkanes and Haloarenes MCQs

Alkyl halides are synthesized through the free radical halogenation of alkanes, the addition of halogen acids to alkenes, or by substituting the -OH group of alcohols with halogens using phosphorus halides, thionyl chloride, or halogen acids. Aryl halides are produced via electrophilic substitution reactions with arenes. Fluorine and iodides are most effectively prepared using the halogen exchange method. These compounds are extensively used in both industrial applications and everyday life, serving primarily as solvents and as precursors for the synthesis of various organic compounds.

Which of the following undergoes nucleophilic substitution exclusively by the SN1 mechanism?

(a) Benzyl chloride
(b) Ethyl chloride
(c) Chlorobenzene
(d) Isopropyl chloride

(a) Benzyl chloride

A Grignard reagent may be made by reacting magnesium with

(a) methyl amine
(b) diethyl ether
(c) ethyl iodide
(d) ethyl alcohol

(c) ethyl iodide

The increasing order of nucleophilicity would be?

(a) Cl⁻ < Br⁻ < I⁻
(b) I⁻ < Cl⁻ < Br⁻
(c) Br⁻ < Cl⁻ < F⁻
(d) I⁻ < Br⁻ < Cl⁻

(a) Cl⁻ < Br⁻ < I⁻

CH₃CH₂CH₂Br + NaCN → CH₃CH₂CH₂CN + NaBr, will be fastest in

(a) ethanol
(b) methanol
(c) N, N-dimethylformamide
(d) water

(c) N, N-dimethylformamide

Which of the following is most reactive towards SN1 reaction?

(a) C₆H₅C(CH₃)C₆H₅Br
(b) C₈H₅CH₂Br
(c) C₆H₅CH(C₆H₅)Br
(d) C₆H₅CH(CH₃)Br

(a) C₆H₅C(CH₃)C₆H₅Br

The C-Cl bond of chlorobenzene in comparison to the C-Cl bond in methyl chloride is

(a) longer and weaker
(b) shorter and weaker
(c) shorter and stronger
(d) longer and stronger

(c) shorter and stronger

The decreasing order of boiling points of alkyl halides is

(a) RF > RCl > RBr > RI
(b) RBr > RCl > RF > RI
(c) RI > RBr > RCl > RF
(d) RCl > RF > RI > RBr

(c) RI > RBr > RCl > RF

Phosgene is commonly known as

(a) thionyl chloride
(b) carbonyl chloride
(c) carbon dioxide and phosphine
(d) phosphoryl chloride

(b) carbonyl chloride

A solution of (+) 2-chloro-2-phenylethane in toluene racemizes slowly in the presence of a small amount of SbCl₅, due to the formation of

(a) carbanion
(b) carbene
(c) free radical
(d) carbocation

(d) carbocation

The reaction of tert-butyl bromide with sodium methoxide produces mainly

(a) isobutane
(b) isobutylene
(c) tert-butyl methyl ether
(d) sodium tert-butoxide

(b) isobutylene