ALKYL HALIDES & ARYL HALIDES

Topper Package chemistry-XII

Permutation and Combinations

Alkyl Halides & Aryl Halides

MULTIPLE CHOICE QUESTIONS

HALIDE & PHYSICAL PROPERTIES

1. The boiling points of alkyl halides and their parent hydrocarbons (RH) are in the order (a) RH > RI > RBr > RCl > RF

(b) RI > RBr > RCl > RF > RH (c) RH > RF > RI > RBr > RCl (d) none of these

2. How many trichloro ethanes would be produced when 1, 1-dichloroethane reacts with chlorine

(a) 1 (b) 2

(c) 3 (d) 4

3. Best yield of alkyl halide





2 2 2

RCO AgX RX CO AgX when X₂is: (a) Cl₂ (b) Br₂

(c) I₂ (d) F₂

4. Iodoform can be prepared from all except: (a) ethyl methyl ketone

(b) isopropyl alcohol (c) 3-methyl-2-butanone (d) isobutyl alcohol

5. Which branched chain isomer of the hydrocar-bon with molecular mass 72u gives only one iso-mer of mono substituted alkyl halide?

(a) Tertiary butyl chloride (b) Neopentane

(c) Isohexane (d) Neohexane

6. The reaction conditions leading to the best yields of C₂H₅Cl are:

(a) C₂H₆ (excess) + Cl₂ UV light  (b) C₂H₆ + Cl_{2 room temperature}dark

(c) C₂H₆ + Cl₂ (excess) UV light  (d) C₂H₆ + Cl₂ UV light  7. (a) (b) (c) (d)

8. Which of the following is added to chloroform in a small quantity before it is bottled for sale? (a) CH₃OH (b) C₂H₅Cl

(c) C₂H₅OH (d) AgNO₃

TOPIC (2) CHEMICAL PROPERTIES

9. The structure of the major product formed in the

following reaction is Cl I NaCN DMF (a) CN CN (b) Cl I NC (c) Cl CN (d) CN I

10. A mixt ure of 1 -chl oro prop ane and 2-chloropropane when treated with alcoholic KOH, gives

(a) prop-1-ene (b) prop-2-ene (c) isopropylene (d) both a & b 11. Identify C in the series,

alc. KOH NB S alc. KC N 3 7

C H I

A

B

C

  

 



  

12. The organic chloro compound, which shows complete stereochemical inversion during a

2

N

S reaction, is

(a) (CH_{3 2}) CHCl (b) CH Cl₃

(c) (C H_{2 5 2}) CHCl (d) (CH_{3 3}) CCl

13. Vicinal and gem dihalides can be distinguished by

(a) aqueous KOH (b) alcoholic KOH (c) Zn dust (d) none of these

14. AgNO d oe s not give pre cip itat e wi th₃

chloroform because

(a) CHCl is insoluble in water₃

Unit

Permutation and Combinations

Alkyl Halides & Aryl Halides

(d) AgNO is insoluble in ₃ CHCl₃

15. The final product formed by distilling ethyl alcohol with excess of Cl₂ and Ca OH( ) is₂ (a) CH CHO₃ (b) CCl CHO₃ (c) CHCl₃ (d) (CH_{3 2}) O

16. The end product (B) in the following sequence of

reactions is CH Cl KCN A H O H2 / B

3



 

(a) CH COOH₃ (b) HCOOH (c) CH NH_{3 2} (d) CH COCH_{3 3}

17. Which one of the following is most reactive towards nucleophilic substitution reaction? (a) CH2 CHCl (b) C H Cl6 5

(c) CH CH₃ CHCl (d) ClCH CH₂ CH₂. 18. In _SN1_{(substitution, nucleophilic, unimolecular)}

reaction, the racemization takes place, it is due to

(a) inversion of configuration (b) retention of configuration (c) conversion of configuration (d) both A and B.

19. Grignard reagent is not prepared in aqueous medium but prepared in ether medium, because (a) the reagent is highly reactive in ether (b) the reagent does not react with water (c) the reagent becomes inactive in water (d) the reagent reacts with water.

20. Tertiary alkyl halides are practically inert to substitution by 2

SN mechanism because of (a) insolubility (b) instability

(c) inductive effect (d) steric hindrance 21. In which of the following reactions, the product

is an ether?

(a) C H_{6 6}CH COCl₃ / anhydrous AlCl₃ (b) C H Cl_{2 5} + aq. KOH

(c) C H6 6C H COCl6 5 /anhydrous AlCl3

(d) C H Cl_{2 5} C H ONa_{2 5}

22. Phosgene is a common name of (a) mixture of CO₂ and Cl₂ (b) POCl₃

(c) carbonyl chloride (d) carbon tetrachloride.

23. Arrange the following halides in the decreasing order of

N

S 1 reactivity

(I) CH CH CH Cl_{3 2 2} (II) CH2 CHCH Cl CH( ) 3

(III) CH CH CH Cl CH_{3 2} ( ) ₃

(a) I > II > III (b) II > I > III (c) II > III > I (d) III > II > I

24. End product of following sequence of reaction is:

Br NH3 _A O3/H O2 _B BaO _C     (a) O (b) OH (c) O (d) HOOC COOH

25. In the following reaction final product is

Br NaI acetone X (a) I X (b) _I X

(c) both (a) and (b) (d) none of these

26. How many chiral compound are possible on monochlorination of 2-methyl butane?

(a) 2 (b) 4

(c) 6 (d) 8

27. Which of the following is the major product of the following reaction?

(a)

Permutation and Combinations

Alkyl Halides & Aryl Halides

The decreasing order of the rate of the above reaction with nucleophiles (Nu–) A to D is: [Nu– _{= (A) PhO}–_{, (B) AcO}–_{, (C) HO}–_{, (D) CH}

3O] (a) D > C > A > B (b) D > C > B > A (c) A > B > C > D (d) B > D > C > A

29. In Finkelstein Reaction, which reactants are used

(a) NaI + C₂H₅OH (b) NaF + acetone (c) NaBr + CH₃OH (d) NaI + acetone

30. Racemic mixture is obtained due to the haloge-nation of

(a) isopentane (b) n-pentane (c) neopentane (d) both (1) and (2) 31. The reaction of SOCl₂ on alkanols to form alkyl

chlorides gives good yields because

(a) alkyl chlorides are immiscible with SOCl₂ (b) the reaction does not occur via intermediate

formation of an alkyl chlorosulphate (c) alcohol and SOCl₂ are soluble in water (d) the other products of the reaction are

gas-eous and escape out 32. For CH₃Br + OH– _{ CH}

3OH + Br

– _{the rate of} reaction is given by the expression

(a) rate = k[CH₃Br] (b) rate = k [OH–_]

(c) rate = k [CH₃Br] [OH–_] (c) rate = k[CH₃Br]0 _[OH–_]0

33. Consider the following reactions, which are car-ried out at the same temperature.

EtOH 3 3 CH _Br_OH _{}CH _OH_Br_...(i) DMSO 3 3 CH _Br_OH _{}CH _OH_Br ...(ii) Which of the following statement is correct about these reactions.

(a) Both the reactions take place at the same rate

(b) The first reaction takes place faster than second reaction

(c) The second reaction takes place faster than first reaction

(d) Both the reactions take place by S_N1 mecha-nism

34. Which of the following is the example of SN2 re-action?

(a)

(b)

(c) (d)

35. Which of the correct reaction coordinate diagram for the following solvolysis reaction?

(a) (b) (c) (d) 36. CH – CH – C (Br) CH 3 3 H3C CH3 MeO K– + X Major Y Major Et COK3

X and Y are respectively: (a) CH3 CH3 C C CH3 CH₃ and C C H H (CH3) CH2 CH3 (b) CH3 CH3 C C CH3 CH3 and C C H H (CH3) CH2 CH3 (c) CH3 CH3 C C CH3 CH3 and C H2 5 C C CH3 C H2 5 C H2 5 (d) H H C C CH3 (CH3)3 and C C CH3 CH3 CH3 CH3

Permutation and Combinations

Alkyl Halides & Aryl Halides

CH₃CH = CHCH₃. The product is: (a) Hoffmann product

(b) Saytzeff product (c) Hoffmann-Saytzeff product (d) Markownikoff product 38. alc.KOH Br A A may be: (a) (b) (c) (d) All of these 39. Br CH CH₃ CH CH₃ CHO C CH₃ OHC C H CH₃

Path of the reaction mechanism: (a) E1 _{(b) E}2 (c) E1

CB (d) both E

1 _{& E}2

40. Consider the following sequence of reaction.

2 3 2 3 NaNH (excess ) CH CH Br 3 2 NH (I) CH CHBrCH Br(A)(B) The two products (A) and (B) are respectively (a) CH C₃ CH and CH CH C_{3 2} CCH₃

(b) CH C3 CNa and (CH ) CHC3 2 CH (c) CH C3 CNa and CH CH C3 2 CCH3 (d) CH C₃ CH and CH CH CH_{3 2} CHCH₃

41. A compound (X), C₄H₈Cl₂, on hydrolysis with aque-ous KOH gives a product (Y) which on heating with I₂ and dilute NaOH gives a yellow precipi-tate of iodoform. The compound (X) is expected to be: (a) CH₃CH₂CH₂CHCl₂ (b) CH₃CH₂CCl₂CH₃ (c) CH₃CH₂CHClCH₂Cl (d) ClCH₂CH₂CH₂CH₂Cl Y = Br₂/CHCl₃ 42. H Br H F+ NaI (1 mole)   2 A ce to ne S N Major (A)_;

Major product of this reaction is:

(a) H I H F _(b) I H H F (c) H Br H I (d) H Br I H

43. Rank the following in order of decreasing rate of solvolysis with aqueous ethanol (fastest  slow-est) (1) H C₂ C Br CH₃ (2) CH₃ Br (3) C CHCH CH(CH )_{2 32} Br CH₃ (a) 2 > 1 > 3 (b) 1 > 2 > 3 (c) 2 > 3 > 1 (d) 1 > 3 > 2

44. Arrange the following three chlorides in decreas-ing order towards SN1 _reactivity.

(1)

Cl (2) _Cl (3) _Cl

(a) 1 > 2 > 3 (b) 2 > 3 > 1 (c) 2 > 1 > 3 (d) 3 > 2 > 1

45. Which of the following alkyl halide undergo rearrangement in SN1 _reaction? (a) C CH CH₃ CH₃ CH₃ CH₃ I (b) Cl CH₃ (c) l (d) All of these 46. Which of the following reactant will not favour

nucleophilic substitution reaction?

(a) Br (b) Ph – Br (c) C CH₂ CH₃ Br CH₃ CH₃

(d) All the above

47. Among the pairs, in which pair first compound reacts faster then second compound in SN1 re-action? (a) CH₃– CH₂– CH₂ – CH₂ – Br or CH₂ CH₃ Br CH CH3 (b) CH₃ C Br CH₂ CH₃ CH₃ or CH_{3 CH} Br CH CH₃ CH₃

Permutation and Combinations

Alkyl Halides & Aryl Halides

(d) Both (a) and (b)

51. CH2–– lC O 3 a 3 N CH ON CH OH(S 1)  Product

Which of the following products can be obtained from above reaction?

(a) CH2–– OCH3 O (b) _O CH₃O (c) O OCH₃ CH₃ (d) All of these

52. What is the principal product of the following re-action? CH₃ CH₃ Cl H Br H H H + NaN3 Product (a) CH₃ CH₃ Cl H N₃ H H H (b) CH₃ CH₃ H H H N₃ H Cl (c) CH₃ CH₃ Cl H H N₃ H H (d) CH₃ CH₃ H H N₃ H H Cl (c) Br or Br (d) CH3 C Br CH₃ CH₃ or CH3 C I CH₃ CH₃ 48. lo g ( ra te ) CH – X3 Me– CH X2– Me CH – X2 Me C – X3 A SN² SN1 B

Which of the following is true about given graphs A and B?

(a) A  S_N1 BS_N2 (b) A S_N2, BS_N1 (c) A & BE₁ (d) A & BE₂

49. In each of the following groups, which is the strongest (best) nucleophile?

(I) (1) H₃C – O– ₍₂₎ O– (3) H₃ C – S– _{in CH} 3OH (II) (1) OH– _{(2) H} 2O (3) NH – 2 in DMF (III) (1) O– (2) _O–(3) CH 3O – _{in DMSO} (a) I,3; II,3; III, 2 (b) I,1; II,1; III, 3(c) I, 1; II, 2;, III, 1 (d) I,3; II, 1; III, 3

50. Which of the following reaction is an elimina-tion reacelimina-tion? (a) H OH _H SO2 4 _ + H (b) H Br H Br KI  + IBr + KBr

Permutation and Combinations

Alkyl Halides & Aryl Halides

(b) B reacts faster than A

(c) Both A and B reacts at the same rate (d) Neither A nor B reacts

58. Most reactive compound toward SN1

(a) CH₂ I (b) CH₂ I (b) CH₂ I (d) CH₂ I 59. C CH OH 2 3 2 3 2 4 1.NaNH (2eq.) __ 2.CH CH I __ 3.CH I __ 4.H /Pd BaSO _{Product (X) is:} (a) CH CH_{2 3} CH ₂ O CH₃ (b) OCH₃ CH CH_{2 3} (c) CH₂ OCH CH_{2 3} CH₃ (d) O CH CH2 3 CH₃

53. Which of the following is most reactive toward SN2 _reaction? (a) CH₂ = CH – CH₂ – Cl (b) Ph – CH₂ – Cl (c) _{Me – O Cl} (d) O Ph – C – CH – Cl2 54. 4-chloro-1-butanol + NaOH (B) Product (B) of the above reaction is:

(a) O (b) O (c) O CH₃ (d) CH₂–CH₃ O

55. Energy profile diagram for an exothermic

reac-tion, 1 2 3

ABCD, is given below:

The slowest rate of step of the reaction is: (a) A  B (b) B  C (c) C  D (d) cannot predict 56. Me₂C = CH – CH₂ – CH₂ – Cl 2 3 H O CaCO (X); Major product of the reaction is:

(a) Me C Me CH₂ CH₂ CH₂ OH (b) Me₂C = CH – CH₂ – CH₂ – OH (c) Me C₂ CH OH CH CH₂ OH (d) _CMe 2 OH

57. Which of the following statements is correct re-garding the rate of hydrolysis of the compounds (A) and (B) by SN1 _{reaction ?}

A

Br O

B

Permutation and Combinations

Alkyl Halides & Aryl Halides

H OH HBr [ ]x  (a) Br H (b) H (c) H Br (d) H OH

TOPIC (3) PREPARATION & PHYSICAL PROPERTIES OF ARYL HALIDE 61. Chlorobenzene is

(a) less reactive than benzyl chloride (b) more reactive than ethyl bromide (c) nearly as reactive as methyl chloride (d) more reactive than isopropyl chloride 62. Westron is

(a) vinyl chloride (b) allyl chloride

(c) dichloroacetaldehyde (d) acetylene tetrachloride

63. C H_{7 8}3Cl2,HeatAFe Br/ 2 BZn HCl/ C

Here, the compound C is

(a) 3-Bromo, 2,4, 6-trichlorotoluene (b) o-bromotoluene

(c) p-bromotoluene (d) m-bromotoluene

64. A solution of (+)-2chloro-2-phenylethane in toluene racemises slowly in the presence of small amount of SbCl₅ due to the formation of (a) Carbanion (b) Carbene

(c) Free-radical (d) Carbocation 65. CH2—CH3 O2N Br2. U.V. light Br2/Fe (A) (B)

(A) & (B) are respectively

(a) CH2CH3 O2N Br and CH2CH3 O₂N Br (b) CH2CH3 ON Br and CH—CH3 Br (c) C2H5 O2N Br and CH—CH3 O2N Br (d) CH—CH3 O2N Br and CH2CH3 O2N Br 66. Consider the two reaction

(I) (C6H )6 Br H + Br2 FeBr₃ (II) D D D D D D + Br2 FeBr3 (C D )6 6 Br D D D D D

Which is the correct statement ?

(a) The rate of bromination is same in both the cases

(b) The rate of bromination in (I) is more than in (II)

(c) The rate of bromination in (II) is more than in (I)

(d) The rate of bromination in (I) is double than in (II)

67. The compound ‘X’ in the following reaction is:

(a) (b)

Permutation and Combinations

Alkyl Halides & Aryl Halides

sunlight to give a product which on hydrolysis followed by reaction with NaOH gives

(a) COOH Cl (b) COOH (c) COONa Na (d) None of these TOPIC (4) CHEMICAL PROPERTIES

69. Aryl halides and Alkyl halides are distinguished by

(a) Alcoholic AgNO₃ (b) Aq. AgNO₃

(c) AgNO /ether₃ (d) AgNO₃/NH₃

70. Silver benzoate will react with bromine in acetone to form (a) (b) Br (c) COOAg Br (d) O || C Br

71. The reaction of toluene with chlorine in the presence of FeCl gives mainly₃

(a) m-chlorobenzene (b) o- and p-chlor toluene (c) benzyl chloride

(d) Benzoyl chloride

72. Which chloroderivative of benzene among the following would undergo hydrolysis most readily with aqueous sodium hydroxide to furnish the corresponding hydroxyderivative? (a) O N2 Cl NO₂ NO₂ (b) O N₂ Cl (c) Me₂N Cl (d) C H_{6 5}Cl

73. Whi ch re pre se nt s nu cle o phil ic aromatic substitution reaction?

(a) reaction of benzene with Cl₂ in sunlight (b) benzyl bromide hydrolysis with water

(c) reaction of NaOH with dinitrofluoro benzene (d) sulphonation of benzene.

74. Chlorination of toluene in presence of light and heat followed by treatment with aqueous NaOH and acidification gives

(a) o-Cresol (b) p-Cresol

(c) 2,4-Dihydroxytoluene (d) benzoic acid

75. The major product obtained when Br2/Fe is

treated with HN CH₃ O H C₃ is (a) HN CH₃ O H C₃ Br (b) HN CH₃ O H C₃ Br (c) HN CH₃ O H C₃ Br (d) HN CH₃ O H C₃ Br

76. The decreasing order of reactivity towards OH

ions is

(I) m-nitrobromobenzene (II) 2,4,6-trinitrobromobenzene (III) p-nitrobromobenzene (IV) 2,4-dinitro bromobenzene

(a) I > II > III > IV (b) II > IV > III > I (c) IV > II > III > I (d) II > IV > I > III

Permutation and Combinations

Alkyl Halides & Aryl Halides

(a) Cl CO H₂ (b) Br CO H₂ CH₃ (c) Br CO H₂ CH₃ (d) Br CO H₂ CH₃

78. In the reaction of p-chlorotoluene with KNH₂ in liq. NH₃, the major product is

(a) o-toluidine (b) m-toluidine (c) p-toluidine (d) p-chloroaniline 79. Which is not the Wurtz-Fittig reaction?

(a) CH2Cl + CH3Cl Na ether/ (b) CH2C +l Cl Na ether/ (c) Cl +CH C3 l Na ether/ (d) None of these 80. H C3 CH3 Cl CH3 FeCl3 CH3NO , 0°C2 A ; A is (a) CH3 CH3 CH3 (b) CH2CH3 CH3 H C3

(c) both are correct (d) none is correct 81. Cl Cl C H CCl3

The above structural formula refers to :

(a) BHC (b) DNA

(c) DDT (d) RNA

82. Which of the following is most reactive towards SN2 _{reaction ?} (a) CH₃ Cl (b) Cl (c) Cl Cl (d) NO₂ Cl 83. S (CH ) – CH – Cl_{2 2} O O 4 2 NaNH

dimethoxy ethane (A);Product(A)

 is: (a) S (CH ) –CH CH2 3 2 O O (b) _S O O (c) S (CH ) –CH NH2 4 2 2 O O (d) None of these

Permutation and Combinations

Alkyl Halides & Aryl Halides

 Major product is (A) is:

(a) Br (b) Br (c) Br (d) Br 85. CH3 Br 2 2 SO Cl NBS KSH hv (A) (B) (C)    , Product (C) is: (a) SH Br (b) SH Cl (c) Br SH (d) Br 86. C CH₃ C14 CH₃ CH₃ H OTs

Major product of the

reaction is: (a) CH₃ CH₃ C 14 C Ph CH₃ (b) HC3 C CH₃ CH Ph CH₂ 14 (c) CH₃ CH₃ C 14 C Ph CH₃ (d) CH₃ CH₃ C 14 C Ph CH₃ 87. Br H H CH3 + OH– SN2  A; The product A is: (a) HO H H CH3 (b) HO H H CH3

(c) Both (a) and (b) are correct (d) None is correct 88. OH CH OH2 HBr Δ  (A), OH OCH3 HBr Δ  (B) Product (A) and (B) respectively are:

(a) OH CH Br2 and OH Br (b) OH CH Br2 and OH OH (c) OH HO CH3 and Br OCH3 (d) Br CH OH2 and Br OCH3

Permutation and Combinations

Alkyl Halides & Aryl Halides

INTEGER TYPE QUESTION

1 . CH C C CH3 3 Br Br Br Br (a ) NaNH 2  (b) CH I3  CH C C C C CH3 3 a and b mole consumed. Value of a + b = 2 . a. Br alc. KOH (A) products b. Br alc. KOH  (B) c. Br alc. KOH (C) d. CH3 CH3 Br Br H alc. KOH (D) Sum of A + B + C + D = 3. a. OH H  (A) b. OH H  (B) c. OH H   (C) d . OH H  (D)

Total number of product obtained in above re-actions including minor product is (includ-ing stereoisomer) 4 . Cl Cl Cl Cl (a ) alC.KOH 

Moles of alc. KOH consumed are:

5 . CH OH2 OH (A) HBr ; Value of (A) is: 6 . Ph CH CH 2 Br Br (X) NaNH2  Ph C C Na+ –

(X = No. of moles of NaNH₂)

7 . O a PCl5  b NaNH2 CH I₃  C C CH3 Cl Sum of a + b = 8 . Cl CH3 CH OH3 _? 

X = Total number of substitution and elimi-nation product (s). Find the value of X. 9 . 1, 2-Dibromopropane on treatment with X

moles of NaNH₂ followed by treatment with C₂H₅Br gives a pentyne. The value of X is :

Permutation and Combinations

Alkyl Halides & Aryl Halides

ANSWER’S

UNIT : 7. ALKYL, ARYL & HALIDE

1. b 2. b 3. b 4. d 5. b 6. a 7. b 8. c 9. d 10. a 11. b 12. b 13. a 14. b 15. c 16. a 17. d 18. d 19. d 20. d 21. d 22. c 23. c 24. c 25. b 26. b 27. b 28. a 29. d 30. d 31. d 32. c 33. c 34. d 35. a 36. a 37. b 38. d 39. c 40. c 41. b 42. b 43. c 44. b 45. d 46. d 47. b 48. b 49. d 50. d 51. d 52. c 53. d 54. b 55. a 56. d 57. b 58. d 59. b 60. c 61. a 62. d 63. d 64. d 65. b 66. a 67. b 68. b 69. a 70. b 71. b 72. a 73. c 74. d 75. a 76. b 77. c 78. b 79. a 80. b 81. c 82. d 83. b 84. a 85. b 86. c 87. b 88. b INTEGER QUESTIONS 1. 8 2. 8 3. 9 4. 2 5. 1 6. 3 7. 5 8. 4 9. 3