JEE Chemistry Haloalkanes and Haloarenes MCQs Set A

Question. Which of the following is a primary halide?
(a) Neohexyl chloride
(b) Secondary butyl iodide
(c) Isopropyl iodide
(d) Tertiary butyl bromide

Answer: A

Question. Gem-dibromide is
(a) CH₃CBr₂CH₃
(b) CH₂BrCH₂Br
(c) CH₂(Br)CH₂CH₂
(d) None of these

Answer: A

Question. How many structural isomers are possible for a compound with molecular formula C₃H₇Cl ?
(a) 2
(b) 7
(c) 5
(d) 9

Answer: A

Question. The compound which contains all the four 1°, 2°, 3° and 4° carbon atoms is
(a) 3-chloro-2, 3-dimethylpentane
(b) 2, 3-dimethyl pentane
(c) 2, 3, 4-trimethylpentane
(d) 3, 3-dimethylpentane

Answer: A

Question. IUPAC name of (CH₃)₃CCl
(a) 2-Chloro-2-methylpropane
(b) 3-Chlorobutane
(c) n-butyl chloride
(d) t-butyl chloride

Answer: A

Question.  Which of the following halide is 2°
(a) Isopropyl chloride
(b) n-propyl chloride
(c) n-butyl chloride
(d) Isobutyl chloride

Answer: A

Question. Benzene hexachloride is
(a) 1, 2, 3, 4, 5, 6 - hexachlorocyclohexane
(b) 1, 1, 1, 6, 6, 6 - hexachlorocyclohexane
(c) 1, 6 - phenyl - 1, 6 - chlorohexane
(d) 1, 1 - phenyl - 6, 6 -chlorohexane

Answer: A

Question. Phosgene is a common name for
(a) carbonyl chloride
(b) carbon dioxide and phosphine
(c) thionyl chloride
(d) phosphoryl chloride

Answer: A

Question. C – X bond is strongest in
(a) CH₃F
(b) CH₃Cl
(c) CH₃Br
(d) CH₃I

Answer: A

Question. Which of the following will have the maximum dipole moment?
(a) CH₃Cl
(b) CH₃I
(c) CH₃F
(d) CH₃Br

Answer: A

Question.  The decreasing order of boiling points of alkyl halides is
(a) RI > RBr > RCl > RF
(b) RF > RCl > RBr > RI
(c) RBr > RCl > RI > RF
(d) RCl > RF > RI > RBr

Answer: A

Question. Halogenation of alkanes is
(a) an oxidative process
(b) an endothermal process
(c) a reductive process
(d) an isothermal process

Answer: A

Question. Ethylene dichloride can be prepared by adding HCl to
(a) Ethylene glycol
(b) Ethylene
(c) Ethane
(d) Acetylene

Answer: A

Question. The best method for the conversion of an alcohol into an alkyl chloride is by treating the alcohol with
(a) SOCl₂ in presence of pyridine
(b) None of these
(c) dry HCl in the presence of anhydrous ZnCl₂
(d) PCl₅

Answer: A

Question. Which of the following is liquid at room temperature (b.p. is shown against it) ?
(a) CH₃I 42ºC
(b) CH₃Br 3ºC
(c) CH₃F –78ºC
(d) None of these

Answer: A

Question. The catalyst used in the preparation of an alkyl chloride by the action of dry HCl on an alcohol is
(a) anhydrous ZnCl₂
(b) anhydrous AlCl₃
(c) FeCl₃
(d) Cu

Answer: A

Question. Chlorobenzene is prepared commercially by
(a) Raschig process
(b) Wurtz Fittig reaction
(c) Friedel-Craft’s reaction
(d) Grignard reaction

Answer: A

Question. In the preparation of chlorobenzene from aniline, the most suitable reagent is
(a) Nitrous acid followed by heating with Cu₂Cl₂
(b) Chlorine in the presence of AlCl₃
(c) Chlorine in the presence of ultraviolet light
(d) None of these

Answer: A

Question. Which of the following possesses highest melting point?
(a) p-dichlorobenzene
(b) m-dichlorobenzene
(c) Chlorobenzene
(d) o-dichlorobenzene

Answer: A

Question. Conant Finkelstein reaction for the preparation of alkyl iodide is based upon the fact that
(a) Sodium iodide is soluble in methanol, while NaCl and NaBr are insoluble in methanol
(b) Sodium iodide is insoluble in methanol, while NaCl and NaBr are soluble
(c) The three halogens differ considerably in their electronegativity
(d) Sodium iodide is soluble in methanol, while sodium chloride is insoluble in methanol

Answer: A

Question. A Grignard reagent may be made by reacting magnesium with
(a) Ethyl iodide
(b) Methyl amine
(c) Diethyl ether
(d) Ethyl alcohol

Answer: A

Question. Which one of the following halogen compounds is difficult to be hydrolysed by S_N1 mechanism?
(a) Chlorobenzene
(b) Isopropyl chloride
(c) Tertiary butyl chloride
(d) Benzyl chloride

Answer: A

Question. The order of reactivity of the given haloalkanes towards nucleophile is
(a) RI > RBr > KCl
(b) RBr > RCl > RI
(c) RCl > RBr > RI
(d) RBr > RI > RCl

Answer: A

Question. In S_N1 reaction, the recemization takes place. It is due to
(a) Both
(b) inversion of configuration
(c) retention of configuration
(d) None of these

Answer: A

Question. The order of reactivities of the following alkyl halides for a S_N2 reaction is
(a) RI > RBr > RCl > RF
(b) RF > RBr > RCl > RI
(c) RF > RCl > RBr > RI
(d) RCl > RBr > RF > RI

Answer: A

Question. S_N2 mechanism proceeds through intervention of
(a) transition state
(b) carbanion
(c) carbonium ion
(d) free radical

Answer: A

Question. Which among MeX, RCH₂X, R₂CHX and R₃CX is most reactive towards S_N2 reaction?
(a) MeX
(b) RCH₂X
(c) R₃CX
(d) R₂CHX

Answer: A

Question. Isopropyl chloride undergoes hydrolysis by
(a) S_N1 and S_N2 mechanisms
(b) S_N2 mechanism
(c) S_N1 mechanism
(d) None of these

Answer: A

Question. Tertiary alkyl halides are practically inert to substitution by S_N2 mechanism because of
(a) inductive effect
(b) insolubility
(c) instability
(d) steric hindrance

Answer: A

Question. Which of the following is an optically active compound ?
(a) 2-Chlorobutane
(b) 1-Butanol
(c) 1-Propanol
(d) 4-Hydroxyheptane

Answer: A

Question. An important chemical method to resolve a racemic mixture makes use of the formation of
(a) diasteromers
(b) a meso compound
(c) enantiomers
(d) racemates

Answer: A

Question. Which of the following will have a mesoisomer also
(a) 2, 3-Dichlorobutane
(b) 2-Chlorobutane
(c) 2-Hydroxypropanoic acid
(d) 2, 3- Dichloropentane

Answer: A

Question. Which of the following compounds is optically active
(a) CH₃CHClCOOH
(b) (CH₃)₂CHOH
(c) (CH₃)₃CCl
(d) None of these

Answer: A

Question. Racemic compound has
(a) equimolar mixture of enantiomers
(b) 1 : 1 mixture of enantiomer and diastereomer
(c) 1 : 1 mixture of diastereomers
(d) 1 : 2 mixture of enantiomers

Answer: A

Question. An organic molecule necessarily shows optical activity if it
(a) is non-superimposable on its mirror image
(b) is superimposable on its mirror image
(c) is non-polar
(d) contains asymmetric carbon atoms

Answer: A

Question. Optically active isomers but not mirror images are called
(a) diastereomers
(b) mesomers
(c) enantiomers
(d) tautomers

Answer: A

Question. Which of the following alkyl halides is used as a methylating agent?
(a) CH₃I
(b) C₆H₅Cl
(c) C₂H₅Cl
(d) None of these

Answer: A

Question. 2-Bromopentane is heated with potassium ethoxide in ethanol. The major product obtained is
(a) trans-2-pentene
(b) 2-ethoxypentane
(c) pentene-1
(d) cis-pentene-2

Answer: A

Question. An alkyl halide reacts with metallic sodium in dry ether. The reaction is known as
(a) Wurtz reaction
(b) Frankland’s reaction
(c) Sandmeyer’s reaction
(d) Kolbe’s reaction

Answer: A

Question. When 2-bromobutane reacts with alcoholic KOH, the reaction is called
(a) dehydrohalogenation
(b) chlorination
(c) halogenation
(d) hydrogenation

Answer: A

Question. An alkyl halide by formation of its Grignard reagent and heating with water yields propane. What is the original alkyl halide ?
(a) Propyl bromide
(b) Ethyl iodide
(c) Methyl iodide
(d) Ethyl bromide

Answer: A

Question. An organic compound A (C₄H₉Cl) on reaction with Na/diethyl ether gives a hydrocarbon which on monochlorination gives only one chloro derivative, then A is
(a) tert-butyl chloride
(b) isobutyl chloride
(c) sec-butyl chloride
(d) n-butyl chloride

Answer: A

Question. Elimination of bromine from 2-bromobutane results in the formation of –
(a) predominantly 2-butene
(b) predominantly 1-butene
(c) predominantly 2-butyne
(d) equimolar mixture of 1 and 2-butene

Answer: A

Question. Reactivity order of halides for dehydrohalogenation is
(a) R –I > R – Br > R – Cl > R – F
(b) R – F > R – Cl > R – Br > R –I
(c) R –I > R – Cl > R – Br > R – F
(d) R – F > R –I > R – Br > R – Cl

Answer: A

Question. Which of following can be used as solvent for grignard reagent ?
(a) C₂H₅OC₂H₅
(b) C₂H₅OH
(c) H₂O
(d) None of these

Answer: A

Question. Benzene reacts with CH₃Cl in the presence of anhydrous AlCl₃ to form
(a) toluene
(b) benzylchloride
(c) chlorobenzene
(d) xylene

Answer: A

Question. Chlorobenzene reacts with Mg in dry ether to give a compound (A) which further reacts with ethanol to yield
(a) Benzene
(b) Phenyl ether
(c) Phenol
(d) Ethylbenzene

Answer: A

Question. Benzene reacts with n-propyl chloride in the presence of anhydrous AlCl₃ to give
(a) Isopropylbenzene
(b) No reaction
(c) n-Propylbenzene
(d) 3 – Propyl – 1 – chlorobenzene

Answer: A

Question. On sulphonation of C₆H₅Cl
(a) ortho and para chlorobenzene sulphonic acids are formed
(b) orthochlorobenzene sulphonic acid is formed
(c) metachlorobenzene sulphonic acid is formed
(d) benzene sulphonic acid is formed

Answer: A

Question. C – Cl bond of chlorobenzene in comparison to C – Cl bon in methyl chloride is
(a) Shorter and stronger
(b) Longer and weaker
(c) Shorter and weaker
(d) Longer and stronger

Answer: A

Question.  Which of the following is not used in Friedel-Crafts reaction?
(a) N–Phenyl acetanilide
(b) Benzene
(c) Bromobenzene
(d) Chlorobenzene

Answer: A

Question. Chlorobenzene can be prepared by reacting aniline with
(a) nitrous acid followed by heating with cuprous chloride
(b) chlorine in presence of anhydrous aluminium chloride
(c) cuprous chloride
(d) hydrochloric acid

Answer: A

Question. Aryl halides can not be prepared by the reaction of aryl alcohols with PCl₃, PCl₅ or SOCl₂ because
(a) carbon-oxygen bond in phenols has a partial double bond character
(b) carbon-oxygen bond is highly polar
(c) all of these
(d) phenols are highly stable compounds

Answer: A

Question. Haloarenes are ortho and para directing due to
(a) Both
(b) + I effect of halogen atom
(c) – I effect of halogen atom
(d) Resonance in aryl halide

Answer: A

Question. Chloropicrin is obtained by the reaction of
(a) nitric acid on chloroform
(b) chlorine on picric acid
(c) nitric acid on chlorobenzene
(d) steam on carbon tetrachloride

Answer: A

Question. Which of these can be used as moth repellant
(a) Hexachloroethane
(b) Benzene hexachloride
(c) Benzal chloride
(d) Tetrachloroethane

Answer: A

Question. Freon (dichlorodifluoro methane) is used
(a) in refrigerator
(b) for dissolving impurities in metallurgical process
(c) as local anaesthetic
(d) in printing industry

Answer: A

Question. Use of chlorofluorocarbons is not encouraged because
(a) They eat away the ozone in the atmosphere
(b) They destroy the oxygen layer
(c) They damage the refrigerators and air conditioners
(d) They are harmful to the eyes of people that use it

Answer: A