JEE Chemistry Haloalkanes and Haloarenes MCQs Set B

Question. Which of the following is used in fire extinguishers
(a) CCl₄
(b) CHCl₃
(c) CH₄
(d) None of these

Answer: A

Question.  Solvent which is used in the synthesis of chlorofluorocarbons
(a) carbon tetrachloride
(b) iodoform
(c) chloroform
(d) methylene chloride

Answer: A

Question. Uses of dichloromethane is
(a) All of the above
(b) metal cleansing and finishing solvent
(c) solvent in drugs manufacturing
(d) paint remover

Answer: A

Question. Chloroform on treatment with conc. HNO₃ gives
(a) Chloropicrin
(b) Picric acid
(c) Nitromethane
(d) Acetylene

Answer: A

Question. Which of the following is responsible for depletion of the ozone layer in the upper strata of the atmosphere
(a) Freons
(b) Ferrocene
(c) Polyhalogens
(d) Fullerenes

Answer: A

Question. Haloforms are trihalogen derivatives of
(a) Methane
(b) Benzene
(c) Ethane
(d) Propane

Answer: A

Question. Which of the following compounds is used as a refrigerant
(a) CCl₂F₂
(b) CCl₄
(c) CF₄
(d) Acetone

Answer: A

Question. Chloroform is used as
(a) Industrial solvent
(b) Insecticide
(c) Fire extinguisher
(d) Refrigerant

Answer: A

Question. AgNO₃ does not give precipitate with CHCl₃ because
(a) CHCl₃ does not ionise in water
(b) CHCl₃ is chemically inert
(c) None of these
(d) Both

Answer: A

Question. When chloroform is exposed to light and air, it forms
(a) phosgene gas
(b) None of these
(c) methyl chloride
(d) carbon tetrachloride

Answer: A

Question. If chloroform is left open in air in the presence of sunlight, it gives
(a) carbonyl chloride
(b) carbon tetrachloride
(c) None of these
(d) lewisite

Answer: A

Question. Freon(s) is/are
(a) All of these
(b) CFCl₃
(c) CClF₃
(d) CCl₂F₂

Answer: A

Question. Freon-12 is commonly used as
(a) refrigerant
(b) a fire extinguisher
(c) insecticide
(d) a solvent

Answer: A

Question. Freon used as refrigerant is
(a) CCl₂F₂
(b) CF₄
(c) CH₂F₂
(d) None of these

Answer: A

Question.  Methylene chloride can be used as
(a) All of these
(b) solvent in manufacturing of drugs
(c) propellant in aerosols
(d) paint remover

Answer: A

Question. Which of the following are the harmful effects of methylene chloride?
(a) All of these
(b) Skin burning
(c) Dizziness, nausea and tingling
(d) Impaired hearing and vision

Answer: A

Question. Following statements are given regarding the preparation of aryl halides from toluene. Read the following statements and choose the correct option.
(i) Aryl chlorides and bromides can be easily prepared by this method.
(ii) The ortho and para isomers formed in the reaction can not be separated easily due to small difference in their melting point.
(iii) Reactions with iodine are reversible in nature and require the presence of an oxidising agent.
(iv) Fluoro compounds are not prepared by this method due to low reactivity of fluorine.
(a) (i) and (iii) are correct
(b) (ii) and (iv) are correct
(c) (i), (ii), and (iii) are correct
(d) All statements are correct

Answer: A

Question.  Read the following statements and choose the correct option.
(i) For the same alkyl group, the boiling points of alkyl halides decreases in the order. RI > RBr > RCl > RF
(ii) With the increases in size and mass of halogen atom, the magnitude of van der Waal’s forces increases
(a) Both statements (i) and (ii) are correct
(b) Statement (i) is correct and (ii) is incorrect
(c) Statement (ii) is correct and (i) is incorrect
(d) Both statement (i) and (ii) are incorrect

Answer: A

Question. Read the following statements and choose the correct answer
(i) The boiling points of isomeric haloalkanes decrease with increase in branching
ii) Among isomeric dihalobenzenes the para-isomers have higher melting point than their ortho and metaisomers.
(iii) The isomeric dihalobenzene have large difference in their boiling and melting points
(iv) The isomeric dihalobenzene have nearly same boiling point
(a) (i), (ii) and (iv) are correct
(b) (ii) and (iv) are correct
(c) (i) and (iii) are correct
(d) (i), (ii) and (iii) are correct

Answer: A

Question. Read the following statements and choose the correct code
(i) S_N2 reaction proceed with complete stereochemical inversion.
(ii) S_N1 reaction proceed with recimisation.
(iii) A dextrorotatory compound rotate the plane polarised light to the left.
(iv) A laevorotatory compound rotate the plane polarised light to the right
(a) TTFF
(b) TFTF
(c) TFTT
(d) FFTT

Answer: A

Question. Assertion : S_N2 reaction of an optically active aryl halide with an aqueous solution of KOH always gives an alcohol with opposite sign of rotation.
Reason : S_N2 reactions always proceed with inversion of configuration.
(a) Assertion is incorrect, reason is correct
(b) Assertion is correct, reason is incorrect
(c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer: A

Question. Assertion : Alkylbenzene is not prepared by Friedel-Crafts alkylation of benzene.
Reason : Alkyl halides are less reactive than acyl halides.
(a) Assertion is correct, reason is incorrect
(b) Assertion is incorrect, reason is correct
(c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer: A

Question. Assertion : Exposure of ultraviolet rays to human causes the skin cancer, disorder and disrupt the immune system.
Reason : Carbon tetrachloride is released into air it rises to atmosphere and deplets the ozone layer.
(a) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(b) Assertion is correct, reason is incorrect
(c) Assertion is incorrect, reason is correct
(d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer: A

Question. Assertion : CHCl₃ is stored in dark bottles.
Reason : CHCl₃ is oxidised in dark
(a) Assertion is correct, reason is incorrect
(b) Assertion is incorrect, reason is correct
(c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(d) Assertion is correct, reason is correct; reason is a correct explanation for assertion

Answer: A

Question. Assertion : CCl₄ is not a fire extinguisher.
Reason : CCl₄ is insoluble in water.
(a) Assertion is incorrect, reason is correct
(b) Assertion is correct, reason is incorrect
(c) Assertion is correct, reason is correct; reason is not a correct explanation for assertion
(d) Assertion is correct, reason is correct; reason is a correct  explanation for assertion

Answer: A

Question. A compound is formed by substitution of two chlorine for two hydrogens in propane. The number of possible isomeric compounds is
(a) 5
(b) 4
(c) 3
(d) 2

Answer: A

Question. Which one of the following is not an allylic halide
(a) 4-Bromobut-1-ene
(b) 1-Bromobut-2-ene
(c) 3-Bromo-2-methylbut-1-ene
(d) 4-Bromopent-2-ene

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) None of these

Answer: A

Question. The number of possible enantiomeric pairs that can be produced during monochlorination of 2-methylbutane is
(a) 1
(b) 3
(c) 2
(d) 4

Answer: A

Question. The number of structural and configurational isomers of a bromo compound, C₅H₉Br, formed by the addition of HBr to 2-pentyne respectively are
(a) 2 and 4
(b) 2 and 1
(c) 1 and 2
(d) 4 and 2

Answer: A

Question. Which of the following reagent produces pure alkyl halides when heated with alcohols?
(a) SOCl₂
(b) PCl₅
(c) PCl₃
(d) dry HCl

Answer: A

Question. If C₅H₁₂ undergoes reaction with chlorine in the presence of sunlight, only one product is formed, than reactant is
(a) 2, 2,-dimethylpropane
(b) 2, 3-dimethylpropane
(c) 3, 3-dimethylpropane
(d) 1, 3-dimethylpropane

Answer: A

Question.  Hydrocarbon (CH₃)₃CH undergoes reaction with Br2 and Cl₂ in the presence of sunlight, if the reaction with Cl is highly reactive and that with Br is highly selective so no.of possible products respectively is (are)
(a) 2, 1
(b) 1, 1
(c) 2, 2
(d) 1, 2

Answer: A

Question. Possible major product formed in the reaction of neopentylalcohol with HCl is
(a) 2 -chloro-2-methylbutane
(b) 2, 2 -dimethyl 1-chloropropane
(c) 2 -chloro -3-methylbutane
(d) 3, chloro -3-methylbutane

Answer: A

Question. Fluorobenzene (C₆H₅F) can be synthesized in the laboratory
(a) from aniline by diazotisation followed by heating the diazonium salt with HBF₄
(b) by heating phenol with HF and KF
(c) by reacting bromobenzene with NaF solution
(d) by direct fluorination of benzene with F₂ gas

Answer: A

Question. The correct order of reactivity of the halides, ethyl chloride (I) iso-propyl chloride (II) and benzyl chloride (III) in S_N1 reaction is
(a) III > II > I
(b) I > III > II
(c) I > II > III
(d) II > I > III

Answer: A

Question. Which of the following represents correct set of ambident nucleophiles?
(a) CN^–, NO₂
(b) CN^–, OH^–
(c) OH^–, RO^–
(d) None of these

Answer: A

Question.  Which of the following statements is correct
(a) All of the above
(b) Carbocation formed in S_N1 reaction is sp² hybridized
(c) S_N1 reactions of optically active halides are accompanied by racemisation
(d) S_N2 reactions of optically active halides are accompanied by inversion of configuration

Answer: A

Question. The replacement of chlorine of chlorobenzene to give phenol requires drastic conditions, but the chlorine of 2, 4-dinitrochlorobenzene is readily replaced since
(a) nitro groups withdraw electrons from ortho/para positions of the aromatic ring
(b) nitro groups donate electrons at meta position
(c) nitro groups withdraw electrons from the meta position of the aromatic ring
(d) nitro groups make the aromatic ring electron rich at ortho/para positions

Answer: A

Question. A set of compounds in which the reactivity of halogen atom in the ascending order is
(a) chlorobenzene, vinyl chloride, chloroethane
(b) chloroethane, chlorobenzene, vinyl chloride
(c) vinyl chloride, chlorobenzene, chloroethane
(d) vinyl chloride, chloroethane, chlorobenzene

Answer: A

Question.  Aryl halides are extremely less reactive towards nucleophilic substitution than alkylhalides. Which of the following accounts for this ?
(i) Due to resonance in aryl halides.
(ii) In alkyl halides carbon atom in C–X bond is sp² hybridised whereas in aryl halides carbon atom in C–X bond is sp³ hybridized.
(iii) Due to stability of phenyl cation.
(iv) Due to possible repulsion there are less chances of nucleophile to approach electron rich arenes.
(a) (i) and (iv)
(b) (i), (ii) and (iv)
(c) (i), (ii) and (iii)
(d) (ii), (iii) and (iv)

Answer: A

Question. The organic compound used as feedstock in the synthesis of chlorofluorocarbons is
(a) CCl₄
(b) CHCl₃
(c) CH₂Cl₂
(d) CH₃Cl

Answer: A

Question. CCl₄ is well known fire extinguisher. However after using it to extinguish fire, the room should be well ventilated. This is because
(a) It produces phosgene by reaction with water vapour at higher temperatures
(b) It is toxic
(c) It is flammable at higher temperatures
(d) It is corrosive

Answer: A

Question. In which part of the atmosphere, does the freon remain unchanged ?
(a) Stratosphere
(b) Mesosphere
(c) Troposphere
(d) Thermosphere

Answer: A

Question. Natural ozone layer is unbalanced due to
(a) initiation of radical chain by freon
(b) presence of rain in the atmosphere
(c) cloudiness of poisonous gases
(d) All of the above

Answer: A

Question. Exposure of CCl₄ causes
(a) All of these
(b) Coma, unconsciousness
(c) Damage to nerve cells
(d) Liver cancer in human

Answer: A

Question. Chloroform cannot be prepared from which of the following
(a) CH₃OH
(b) C₂H₅OH
(c) CH₃CHO
(d) None of these

Answer: A