ORGANIC COMPOUNDS CONTAINING HALOGENS – 1

1) Which among the following is used as an anaesthetic?
a) 1-bromo-1-chloro-2,2,2-tri fluoro ethane
b) 1,1,1-tri iodomethane
c) dichloro – di fluoro methane
d) lindane

2) A chemical used as a fumigant in food storage godowns
a) 1,2-dichloro ethane
b) 1,2-dibromo ethane
c) octadecanoic acid
d) methyl ethyl ketone

3) An unknown compound A has a molecular formula C4H6. When A is treated with an excess of
Br2, a new substance B with formula C4H6Br4 is formed. A forms a white precipitate with

a) Butyne-1
b) Butyne-2
c) Butene-1
d) Butene-2.

4) When acetylene reacts with arsenic trichloride in the presence of anhydrous aluminium chloride, 7 it produces
a)
b) Trivinylarsine
c) Nitrobenzene
d) Trichlorovinylaluminium

5) The reaction,
CH2 = CHCH3 + HBr CH3CHBrCH3 is a type of

a) Electrophilic addition reaction
b) Nucleophilic addition reaction
c) Free radical addition reaction
d) Electrophilic substitution reaction.

6) Propene reacts with HBr to form
a) Propane
b) Ethane
c) Hexane
d) 2-Bromopropane.

7) Which of the following is not ferromagnetic?
a) Ni
b) Co
c)
d) none of the above

8) The reaction,
CH3CH2Br CH2 = CH2 + H20 +Bris an example of

a) Addition reaction
b) Subsbtitution reaction
c) Elimination reaction
d) Rearrangement reaction.

9) 1,2-Dibromoethane when heated with alcoholic potash gives
a) Ethane
b) Acetylene
c) Ethylene
d) Methane.

10) The reaction,

CH3CHBr – CH2Br + 2 KOH (alc.) CH3C CH + 2 KBr + 2 H2O is called
a) Dehalogenation
b) Dehydrohalogenation
c) Decarboxylation
d) Dehydration.

11) The reaction,

is an example of
a) Hydration
b) Dehydration
c) Dehydrogenation
d) Dehalogenation.

12) Electrolysis of a concentrated solution of potassium acetate gives
a) Methane
b) Ethane
c) Ethene
d) Ethyne

13) One of the following cannot be prepared by Kolbes electrolytic process
a)
b)
c)
d)

14) Which of the following hydrocarbons is formed when an electric discharge is passed between graphite electrodes in an atmosphere of hydrogen ?
a)
b)
c)
d)

15) Propyne is formed by reaction of
a)
b)
c)
d)

16) The product obtained when chloroform is heated with silver powder is
a) Ethyne
b) Ethane
c) Ethene
d) Methyl chloride.

17) The gas believed to be the cause of explosion in coal mines or damp fire is
a) Methane
b) Acetylene
c) CO
d) Hydrogen.

18) ln the following selective reaction

HCCH + H2CH2 = CH2, X is
a)
b)
c) Raney Nickel
d) Conc. HI in presence of red P.

19) Acetylene produced by the action of water on calcium carbide generally has a foul smell due to
a) its characteristic smell
b)
c)
d)

20) Addition of HBr to 2-methyl-1-propene in the presence of hydrogen peroxide mainly forms
a) 1-Bromobutane
b) 2-Bromopropane
c) 2-Bromo-2-methylpropane
d) 1 -Bromo-2-methylpropane.

21) The reaction, CH2 = CH2 + H2O + [O] HOCH2-CH2OH is called
a) Hydroxylation
b) Decarboxylation
c) Hydration
d) Dehydration.

22) Cyclohexene reacts with cold dilute alkaline KMnO4 to yield
a) cis-1, 2-Cyclohexanediol
b) trans-1, 2-Cyclohexanediol
c) Cyclohexanone
d) Hexane-1,6-dial.

23) Treatment of ethylene with ozone followed by decomposition of the product with Zn/H2O gives two moles of
a) Formaldehyde
b) Acetaldehyde
c) Formic acid
d) Acetic acid.

24) The position of double bond in an alkene can be located with the help of
a) Ozonolysis
b)
c) Hydration
d) Both (a) and (b).

25) There are three isomeric butenes (1-butene, 2-butene and 2- methylpropene). These can be distinguished from one another by
a) Bromine in carbon tetrachloride
b)
c) Ammoniacal silver nitrate solution
d) Ozonolysis.

26) Treatment of ethylene with oxygen at 575 K in presence of silver catalyst gives
a) Acetaldehyde
b) Ethylene oxide
c) Ethylene glyco
d) Ethyl alcohol.

27) @ An alkene with molecular formula C6H12 upon ozonolysis gives only one product which does not reduce Fehlings solution . The alkene is
a) 3-Hexene
b) 2-Hexene
c) 2-Methyl-2-pentene
d) 2, 3-Dimethyl-2-butene.

28) The reaction of alkenes with halogens is explosive in the case of
a)
b)
c)
d)

29) Acetylene when treated with dilute HCI at 60°C (333 K) in presence of HgCI2 produces
a) Methyl chloride
b) Vinyl chloride
c) Acetaldehyde
d) Formaldehyde.

30) Acetylenic hydrogens are acidic because
a) the sigma electron density of C-H bond in acetylene is nearer to carbon, which has 50%
b) Acetylene has only one hydrogen on each carbon
c) Acetylene contains the least number of hydrogens among the possible hydrocarbons having two carbons
d) The sigma electron density of C-H bond in acetylene is nearer to hydrogen, which has 100%

31) The chlorination of an alkane involves the attack of
a) An electrophile
b) A nucleophile
c) A base
d) A free radical.

32) Pentene-1 with HCI gives
a) 3-Chloropentane
b) 2-Chloropentane
c) 1, 2-Dichloropentane
d) 1 -Chloropentane.

33) Acetylene reacts with arsenic trichloride to form
a) Lewisite
b) Isoprene
c) Mustard gas
d) Chloropicrin.

34) Which of the following is the predominant product in the reaction of HOBr with propene ?
a) 2-Bromo-1-propanol
b) 3-Bromo-1-propanol
c) 2-Bromo-2-propanol
d) 1-Bromo-2-propanol.

35) Two gases, P and Q decolourise aqueous bromine but only one of them gives a white
precipitate with aqueous ammoniacal silver nitrate solution. P and Q are likely to be

a) Ethane and ethyne
b) But-1-yne and but-2-yne
c) Ethane and but-2-yne
d) Ethyne and propyne.

36) The products formed by the action of chlorine on ethene in saturated solution of KBr is/are
a)
b) alone
c)
d)

37) The principal organic product formed in the CH2=(CH2)8COOH + HBr is
a)
b)
c)
d)

38) The addition of HBr is easiest with
a)
b)
c)
d)

39) How many monochlorobutanes will be obtained on chlorination of n-butane ?
a) 1
b) 2
c) 3
d) 4

40) Arrange the following compounds in increasing order of reactivity towards the addition of HBr. RCH=CHR, CH2=CH2, R2C=CHR, R2C=CR2
a)
b)
c)
d)

41) 1, 3-Butadiene when treated with Br2 gives one of the following as the major product:
a) 1,4-dibromo-2-butene
b) 1,3-dibromo-2-butene
c) 3, 4-dibromo-2 -butene
d) 2, 3-dibromo-2-butene.

42) In presence of peroxide, hydrogen chloride and hydrogen iodide do not give anti-Markovnikovs addition to alkenes because
a) both are highly ionic
b) one is oxidising and the other is reducing
c) one of the steps is endothermic in both the cases
d) all the steps are exothermic in both the cases.

43) Bromination of 2 – methylpropane can be selectively performed to obtain
a) 2-Bromo-2-methylpropane
b) 1-Bromo-2-methylpropane
c) 1,3 – Dibromo-2-methylpropane
d) 1,1,1-Tribromo-2-methylpropane

44) Free radical monochlorination of tert-butyl bromide gives
a) 1 -Bromo-2-chloro-2-methylpropane
b) 2-Bromo-1 -chloro-2-methylpropane
c) 1 -Bromo-1 -chloro-2-methylpropane
d) None of the above.

45) Which one of the following explains why propene undergoes electrophilic addition with HBr, but not with HCN ?
a)
b) HBr is a stronger acid than HCN and henc a better source of protons
c) HCN reacts preferentially via the lone pair i electrons
d) The C – Br bond is stronger than C-CN.

46) An example of chlorinolysis is
a)
b)
c)
d)

47) Addition of I— Br to 2-methyl-2-butene would form
a) 2-Bromo-3-iodobutane
b) 2-Bromo-3-iodo-2-methylbutane
c) 2-lodo-3-bromobutane
d) 2-Bromo-2-iodopentane.

48) Addition of HCI to 3, 3, 3-trichloropropene give
a)
b)
c)
d)

49) lndicate the structure of the organic product expected when 2- methylpropene is heated with acetyl chloride in the presence of anhydrous zinc chloride.
a)
b)
c)
d)

50) The product formed when vinylacetylene is passed through concentrated hydrochloric acid in presence of cuprous and ammonium /chlorides is
a)
b)
c)
d)

51) Acid chlorides react with acetylene in the presence of anhydrous aluminium chloride to give
a) RCOCH = CHCI
b)
c)
d) Both (a) and (b).

52) At low temperature, the slow addition of bromine to CH2 = CH-CH2-C CH, gives
a)
b)
c)
d)

53) The addition of HBr to 2-pentene gives
a) 2-Bromopentane only
b) 3-Bromopentane only
c) Both 2-bromopentane and 3-bromopentane is nearly equal amounts
d) Both 2-bromopentane and 3-bromopentane in the ratio 5: 1.

54) Toluene when treated with Br2/Fe, gives p- bromotoluene as the major product. Which of the following is not true about this reaction?
a) CH3 is p-directing
b) CH3 is a deactivating group
c) CH3 activates the ring by hyperconjugation
d) Fe acts as a catalyst

55) Thionyl chloride method is preferred over phosphorus pentachloride method for the preparation of alkyl chlorides because
a) PCI 5
b) The by-products escape leaving behind almost pure alkyl chloride
c) Thionyl chloride is cheap
d) None of the above

56) Alkyl halides can be prepared by all the following methods except
a)
b)
c)
d)

57) The alkyl halides that can be made by free radical halogenation of alkanes are
a) RCI and RBr but not RF or Rl
b) RF, RCI and RBr but not Rl
c) RF, RCI, RBr, Rl
d) RF, RCI and Rl but not RBr.

58) Allylic bromination is carried out with
a)
b) HOBr
c)
d) NBS.

59) (CH3)3C-Cl The compound B in the above sequence is
a) 3-Chloro-2-methylpropene
b) 1-Chloro-2-methylpropene
c) 1,2-Dichloro-2-methylpropene
d) 1,2-Dichloro-2-methylpropene.

60) The product formed when benzenediazonium chloride is treated with CuBr/HBr is
a) Bromobenzene
b) Chlorobenzene
c) 1,3-Dibromobenzene
d) 1, 4-Dichlorobenzene.

61) Which of the following cannot be prepared by the direct halogenation of benzene ?
a) lodobenzene
b) Chlorobenzene
c) Bromobenzene
d) Fluorobenzene.

62) Fluorobenzene can be conveniently prepared by
a) heating benzenediazonium tetrafluoro borate
b) treating benzene with F2
c) the action of phenol with sulphur hexaflouride
d) treating benzene with freon in presence of anhyd. Aluminium chloride

63) Of the following alkyl halides, the one with the lowest boiling point is
a) Ethyl bromide
b) Isopropyl bromide
c) n-Butyl bromide
d) Methyl bromide.

64) Alkyl halides are almost insoluble in water because
a) They are covalent compounds
b) They have low polarity
c) They do not form hydrogen bonds with water
d) They have tetrahedral geometry.

65) Of the following alkyl halides, the one having the highest polarity is
a)
b)
c)
d)

66) Arrange CH3F, CH3CI, CH3Br and CH3I in the decreasing order of their dipole moment
a)
b)
c)
d)

67) Which of the following alkyl halides has the maximum density ?
a)
b)
c)
d)

68) Among the following derivatives of ethane, the one having the highest boiling point is
a)
b)
c)
d)

69) Amongst the following, the most reactive alkyl halide is
a)
b)
c)
d)

70) Which of the following is most reactive towards nucleophilic substitution reactions ?
a)
b)
c)
d) None of the above.

71) Which of the following alkyl halides is hydrolysed by SN1 mechanism ?
a)
b)
c)
d)

72) SN1 reactions occur through the intermediate formation of
a) Carbocations
b) Carbanions
c) Free radicals
d) None of these.

73) SN1 reactions are favoured by
a) Non-polar solvents
b) Bulky groups on the carbon atom attached to the halogen atom
c) Small groups on carbon atom attached to the halogen atom
d) None of these.

74) Which of the following alkyl halides is hydrolysed by mechanism ?
a)
b)
c)
d)

75) An optically active halide when allowed to react with CN gives a racemic mixture. The halide is most likely to be
a) Primary
b) Secondary
c) Tertiary
d) None of the above.

76) Which of the following is the correct order of decreasing reactivity towards the nucleophilic substitution reaction ?
a) n-Propyl chloride > Allyl chloride > Vinyl chloride
b) Allyl chloride > n-Propyl chloride > Vinyl chloride
c) Allyl chloride > Vinyl chloride > n-Propyl chloride
d) Vinyl chloride > Allyl chloride > n-Propyl chloride.

77) Arrange the following, CH3CH2CH2CI (I),CH3CH2-CHCI-CH3 (II) (CH3)2CHCH2CI (III)
and (CH3)3C-CI (IV) in the order of decreasing tendency towards SN2 reaction

a) l>lll > II > IV
b) III > IV > II > I
c) ll>l > III > IV
d) IV > Ill > II > I

78) A dextrorotatory optically active alkyl halide undergoes hydrolysis by mechanism. The resulting alcohol is
a) Dextrorotatory
b) Laevorotatory
c) Optically inactive due to racemization
d) dextro-or laevorotatory.

79) Acetonitrile is prepared by treating an alcoholic solution of methyl iodide with
a) Silver cyanide
b) Potassium cyanide
c) Hydrogen cyanide
d) Ammonia

80) The major product formed when methyl iodide reacts with sodium nitrite is
a) Methyl nitrite
b) Nitromethane
c) Nitrous acid
d) Nitroethane.

81) Alkyl halides react with an alcoholic solution of ammonia to give a mixture of
a) Primary and secondary amines only
b) Primary and tertiary amines only
c) Primary, secondary and tertiary amines only
d) Primary, secondary, tertiary amines and the quarternary ammonium salts

82) For the preparation of ethyl propionate from ethyl bromide, the other reactant can be
a) Silver acetate
b) Propionic anhydride
c) Propanoyl chloride
d) Silver propionate

83) Identify Z in the following sequence of reactions
a)
b)
c)
d)

84) What is the correct order of reactivity of the following alkyl halides : CH3CH2CI, CH3CHCICH3 and (CH3)3CCI , towards dehydrohalogenation ?
a)
b)
c)
d)

85) When two alkenes may be formed by dehydrohalogenation of an alkyl halide, the alkene which is most highly substituted predominates. This generalization is called the
a) Markownikov rule
b) Saytzeff rule
c) Hoffmann rule
d) Peroxide effect.

86) When 2-chlorobutane is treated with alcoholic KOH, the major product formed is
a) 1-Butene
b) 2-Butene
c) 1-Butyne
d) 2-Butyne

87) A mixture of 1-chlorobutane and 2-chlorobutane when treated with alcoholic KOH gives
a) 1-Butene
b) 2-Butene
c) Isobutylene
d) A mixture of 1-butene + 2-butene.

88) Which of the following alkyl halides when subjected to dehydrohalogenation by the action of
ethanoeic KOH would yield CH3CH = C(CH3)2 as the major product?

a)
b)
c)
d)

89) Choose the incorrect reaction
a)
b)
c)
d)

90) @ The halide which will not react with benzene in the presence of anhydrous AICI3 is
a)
b)
c)
d)

91) Chlorobenzene on treatment with acetyl chloride and anhyd. AICI3 gives
a) o-Chloroacetophenone
b) p-Chloroacetophenone
c) o- and p-Chloroacetophenone
d) m-Chloroacetophenone.

92) A convenient reagent for the conversion of bromobenzene into benzonitrile is
a) Alc. KCN alone
b) KCN and pyridine
c) Silver cyanide
d) CuCN and pyridine.

93) Wurtz-Fittig reaction involves the action of sodium metal on
a) Two molecules of an alkyl halide
b) One molecule of an alkyl halide and one molecule of an aryl halide
c) Two molecules of an aryl halide
d) Two molecules of chloroform.

94) ,   The compound X is
a) Phenol
b) Benzene
c) o- and p-Chlorophenol
d) Benzol

95) Which of the following is least reactive towards the nucleophilic displacement reaction when treated with aqueous KOH ?
a) 2, 4,6-Trinitrochlorobenzene
b) 2, 4-Dinitrochlorobenzene
c) 4-Nitrochlorobenzene
d) 3-Nitrochlorobenzene.

96) Which of the following is not formed when CI2 is passed through boiling toluene in the presence of light?
a) Benzyl chloride
b) Benzal chloride
c) Benzotrichloride
d) o- and p-chlorotoluene.

97) Among the following which one has the weakest carbon-halogen bond ?
a) Benzyl bromide
b) Bromobenzene
c) Vinyl bromide
d) Benzyl chloride.

98) Ethyl bromide (A) can be differentiated from bromobenzene (b) by treating with aqueous
KOH solution because

a) A forms alcohol easily
b) B forms phenol easily
c) A does not react
d) B gives o-bromophenol

99) X on treatment with NaOH at room temperature followed by acidification with dil. HNO3 and addition of AgNO3 gives a white precipitate soluble in NH4OH solution. The compound X is
a) Chlorobenzene
b) Benzyl chloride
c) Ethyl bromide
d) Vinyl chloride.

100) The halide which does not give precipitate when warmed with alcoholic AgNO3 solution is
a) Chlorobenzene
b) Benzyl chloride
c) Allyl chloride
d) Tert-Butyl chloride.


Answer

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