UNIT : 10- HALOALKANES & HALOARENES · Alkyl halides, though polar, are immiscible with water. Why...

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NBS GURUKUL , SCF 5 ,GTB NAGAR , JALANDHAR-0181-5072918, 2976308

NBS GURUKULTARGET X+2-2020

CHEMISTRYHALOALKANES

WORK SHEET-1TOPIC : METHODS OF PREPRATION &

PHYSICAL PROPERTIESProf. Adarsh Bhatti

M.Sc. (Gold Medalist)I. NCERT PROBLEMS1. Identify all the possible monochloro structural isomers expected to be formed on free radical

monochlorination of (CH3)2CHCH2CH3.2. Write the products of the following reactions :

3. Why is sulphuric acid not used during the reactions of alcohols with KI.4. Write structures of different dihalogen derivatives of propane.5. Among the isomeric alkanes of molecular formula C5H12. Identify the one that on photochemical

chlorination yields.(i) A single monochloride (ii) Three isomeric monochlorides (iii) Four isomeric monochlorides.

6. Arrange each set of compounds in order of increasing boiling points.(a) Bromomethane, bromoform, chloromethane, dichloromethane(b) 1-Chloropropane, isopropyl chloride, 1-chlorobutane

7. Draw the structure of major monohalo product in each of the following reactions.

8. Which of the following has highest dipole moment ? (a) CH2Cl2 (b) CHCl3 (c) CCl49. A hydrocarbon C5H10 does not react with chlorine but gives a single monochloro compound, C5H9 Cl in

bright sunlight. Identify the hydrocarbon.10. Write the isomers of the compound having formula C4H9Br.11. Write the equations for the preparation of 1-bromobutane from (a) 1-butanol (b) 1-chlorobutane

(c) but-1-ene.12. Alkyl halides, though polar, are immiscible with water. Why ?II. CBSE ProblemsCBSE 200813. Write the IUPAC names of the following compounds :

a. (CH3)3CCH2Br

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CH2Cl(ii)

14. What happens when bromine reacts with CH3 – C ≡ CH ? How would you justify this reaction ?CBSE 200915. Complete the following reaction equations :

CH3

(i) + HI (ii) CH3CH2CH = CH2 + HBr

CBSE 201016. Give the IUPAC name of the following compound :

H3C CH3

HH

CH3 BrCBSE 201117. Write the IUPAC name of the following compound :

CH2 = CHCH2BrCBSE 201218. What happens when bromine attacks CH2 = CH – CH2 – C ≡ CH ?CBSE 2013Write the IUPAC name of the following compound :

CH3 - CH - CH2 - CH - CH3

| |Br Cl

CBSE 201419. Identify the chiral molecule in the following pair :

20. (a) Draw the structures of major monohalo products in each of the following reactions :

CBSE 201621. Write the major monohalo product(s) in each of the following reactions :

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III. JEE MAINS/NEET PROBLEMS22. The reactivity of the halogen acids in reaction of alcohols with halogen acids is HI > HBr > HCl. Expalin

why?23. The reactivity of alcohols in reaction of alcohols with halogen acids is 3o > 2o > 1o Explain why?24. Treating 3-methyl-2-butanol with HBr yields 2-bromo-2-methylbutane as the sole product. Outline a

mechanism for the reaction.25. What mass of isobutylene is obtained from 37 g of tert. butyl alcohol by heating with 20% H2SO4 at 363 K,

if the yield is 65%? Ans. 18.20 g26. ROH does not react with KBr, but when H2SO4 is added, the reaction takes place. Comment.27. Starting with alcohols, outline a synthesis of each of the following : (a) benzyl bromide; (b) cyclohexyl

chloride; (c) butyl bromide.28. Monochlorination of ethane to ethyl chloride is more practicable than the monochlorination of n-pentane.

Assign reason.29. Why are halogen acids in the dry state and not in aqueous solution are preferred while preparing alkyl halides

from alkenes ?30. The dipole moment of chloromethane is more than fluoromethane. Explain.31. RCl is hydrolysd to ROH slowly, but reaction takes place at a faster rate if catalytic amount of KI is added to

the reaction mixture. Explain.32. Why thionyl chloride method is preferred for the preparing alkyl chloride from alcohols ?33. Explain why the boiling point of bromoethane is higher than that of chloroethane.?34. Explain why alkyl halides are generally not prepared in the laboratory by free radical halogenation of alkanes.35. Explain why chlorination of n-butane in presence of light at 298K gives a mixture of 72% of 2-chlorobutane

and 28% of 1-chlorobutane.36. The order of reactivity of following alcohols with halogen acids is ……..

CH3

|(A) CH3CH2 – CH2 – OH (B) CH3CH – CH – OH (C) CH3CH2 – C – OH

| |CH3 CH3

a) (A) > (B) > (C) (b) (C) > (B) > (A) (c) (B) > (A) > (C) (d) (A) > (C) > (B)37. Which of the following alcohols will yield the corresponding alkyl chloride on reaction with

concentrated HCl at room temperature ?CH3

|a) CH3CH2 – CH2 – OH (b) CH3CH2 – CH – OH (c) CH3CH2– CH – CH2OH (d) CH3CH2–C –OH

| | |CH3 CH3 CH3

38. Which of the following is halogen exchange reaction ?

39. Which reagent will you use for the following reaction ?CH3CH2CH2CH3 → CH3CH2CH2CH2Cl + CH3CH2CHClCH3

a) Cl2/UV light (b) NaCl + H2SO4 (c) Cl2gas in dark (d) Cl2 gas in the presence of iron in dark40. Arrange the following compound in increasing order of their boiling point.

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a) II < I < III (b) I < II < III (c) III < I < II (d) III < II < I41. Which of the following is an example of vic-dihalide ?

a) Dichloromethane (b) 1, 2-Dichloroethane (c) Ethylidene chloride (d) Allyl chloride42. The position of –Br in the compound in CH3CH = CHC(Br)(CH3)2 can be classified as …….

a) Allyl (b) Aryl (c) Vinyl (d) Secondary43. Ethylidene chloride is a/an ……………

a) Vic-dihalide (b) gem-dihalide (c) Allylic halide (d) vinlic halide44. What is ‘A’ in the following reaction ?

45. Which is the correct increasing order of boiling points of the following compounds points of thefollowing compounds ?1-Iodobutane, 1-Bromobutane, 1-Chlorobutane, Butanea) Butane < 1-Chlorobutane < 1-Bromobutane < 1-Iodobutaneb) 1-Iodobutane < 1-Bromobutane < 1-Chlorobutane < Butane < 1-Butanec) Butane < 1-Iodobutane < 1-Bromobutane < 1-Chlorobutaned) Butane < 1- Chlorobutane < 1-Iodobutane < 1-Bromobutane

46. Which of the following compounds are gem-dhalides ?a) Ethylidene chloride (b) Ethylene dichloride (c) Methylene chloride (d) Benzyl chloride

47. Which of the following are secondary bromides ?a) (CH3)2CHBr (b) (CH3)3CCH2Br (c) CH3CH(Br)CH2CH3 (d) (CH3)2CBrCH2CH3

48. Alkyl halides are prepared from alcohols by treating witha) HCl + ZnCl2 (b) Red P + Br2 (c) H2SO4 + KI (d) All the above

49. Alkyl fluorides are synthesized by heating an alkyl chloride/bromide in presence of …….. of …….a) CaF2 (b) CoF2 (c) Hg2F2 (d) NaF

IV. JEE ADVANCED PROBLEMS50. Write down the structures of A and B in the following sequence of reactions.

NaNH2, MeI Na/NH3(i)PhC ≡ CH A B

51. 1-Bromo-1-methylcyclohexane can be obtained by the addition of HBr on

a) (b) (c) (d) both from (b) and (c)

52. + HBr ―――→ X

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In the above reaction, X isBr

a) (b) Br (c) (d)Br Br

Br53. Which one of the following method gives good yield for preparing cyclohexanenitrile ?

CN- I- CN-

a) Cl ―→ CN (b) Cl ―→ I ―→ CN

c) Both methods give equally good yieldd) Neither of the two methods can be applied because each has its own drawback

NBS54. CH2 = CHCH2 CH = CH2 A. A is :

(a) CH2 = CHCHCH = CH2 (b) CH2 = CHCH = CHCH2 Br

Br(c) CH2 = CHCH2 CH = CHBr (d) CH2 = CHCH2 ( Br) C = CH2

55. The major product formed in the reactionCH2 NBS

isCCl4, ∆

CH3 CH2Br Br CH2Br

(a) (b) (c) CH3 (d)

Br56. Which of the following has the highest nucleophilicity ?

a) F− (b) OH− (c) CH3− (d) NH2

−

WORK SHEET-2TOPIC : OPTICAL ISOMERISM

I. NCERT PROBLEMS57. Identify chiral and achiral molecules in each of the following pair of compounds.

(iii) CH3CHCH2CH3 (iv) CH3CH2CH2CH2Br|Br NCERT

II. CBSE Problems58. What is meant by chirality of a compound ? Give an example CBSE-2012III. JEE MAINS/AIPMT PROBLEMS59. Which of the following acids does not exhibit optical isomerism ?

(1) Lactic acid (2) Tartaric acid (3) Maleic acid (4) α-amino acids AIPMT-2012

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60. How many chiral compounds are possible on monchlorination of 2-methyl butane ? AIEEE-2012a) 8 (b) 2 (c) 4 (d) 6

61. The number of optically active products obtained from the complete ozonolysis of the given compound is

a) 0 (b) 1 (c) 2 (d) 4 IIT-201262. In which of the following molecules carbon atom marked with asterisk (*) is asymmetric ?

a) I, II, III, IV (b) I, II, III (c) II, III, IV (d) I, III, IV NCERT63. Which of the following structures is enantiomeric with the molecule (A) given below:

NCERT

64. Which of the carbon atoms present in the molecule given below are asymmetric ?

NCERTa) I, II, III, IV (b) II, III (c) I, IV (d) I, II, III

65. Which of the following compounds has (have) a meso isomer ?(a) 2,4-dibromohexane (b) 2,3-dibromobutane. (c) 2,4-dimethyl pentane (d) Hexane-2,5-diol.

IV. JEE ADVANCED PROBLEMS66. Which of the following is (are) a pair of distereomers?

67. Which of the following is correctly matched?

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68. Which of the following compound(s) can show both enantiomerism as well as distereomerism?

69. Absence of which of the following is not essential for optical isomerism?(a) Plane of symmetry (b) Center of symmetry (c) Axis of symmetry (d) Alternating axis of symmetry

70. An optically pure compound X gave an [α] = + 200.A mixture of X and its enantiomer Y gave an [α] = +l0 0

The ratio of X to Y in the mixture is(a) 2:1 (b) 1:3 (c) 3:1 (d) 1:2

71. The following pair of isomers are related as

(a) They are enantiomers (b) They are distereomers.(c) They are identical and meso (d) They are identical and enantiomeric

72. Out of the following which are chiral?

(a) I, II (b) II, III (C) I, III (d) only III73. Dimethylcyclohexane that has a plane of symmetry is

74. The total number of stereoisomers that can exist for M is :

JEE ADVANCED-201575. Compound(s) that on hydrogenation produce(s) optically compound(s) is (are) -

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JEE ADVANCED-201576. The structure of D-(+)-glucose is

The structure of L(-)-glucose is JEE ADVANCED-2015

77. The correct statement(s) for the following addition reactions is(are)

JEE ADVANCED-2017(A) (M and O) and (N and P) are two pairs of diastereomers(B) Bromination proceeds through trans-addition in both the reactions(C) O and P are identical molecules(D) (M and 0) and (N and P) are two pairs of enantiomers

WORK SHEET-3TOPIC : CHEMICAL PROPERTIES

I. NCERT PROBLEMS78. Haloalkanes react with KCN to form alkyl cyanides as main product while AgCN forms isocyanides as the

chief product. Explain.79. Explain the following reaction :

EtOH – H2ON – BuBr + KCN ――――――→ n – BuCN.

80. In the following pairs of halogen compounds, which would undergo SN2 reacion faster ?

CH2Cl and Cl : I and Cl81. Predict the order of reactivity of the following compounds in SN1 and SN2 reactions :

(i) The four isomeric bromobutanes(ii) C6H5CH2 Br, C6H5CH (C6H5)Br, C6H5CH(CH3)Br, C6H5C(CH3) (C6H5)Br

82. Which alkyl halide from the following pairs would you expect to react more rapidly by SN2 mechanism ?

Explain your answer.CH3

(i) CH3CH2CH2CH2Br or CH3CH2― CH ― CH3 (ii) CH3CH2 ― CH ― CH3 or H3C ― C ― Br

Br Br CH3

(iii) CH3 ― CH ― CH2CH2 Br or CH3CH2 ― CH ― CH2Br

CH3 CH3

83. In the following pairs of halogen compounds, which compound undergoes faster SN1 reaction ?

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84. Identify A, B, C, D, E, R and R1 in the following :

85. Which compound in each of the following pairs will react faster in SN2 reaction with OH- ?

(a) CH3Br or CH3I (b) (CH3)3CCl or CH3Cl.86. Predict all the alkenes that would be formed by dehydrohalogenation of the following halides with sodium

ethoxide in ethanol and identify the major alkane.a) 1-Bromo-1-methylcyclohexane (b) 2-Chloro-2methylbutanec) 2, 2, 3-Trimethyl-3-bromopentane

87. How will you bring the following conversions ?(a) Ethanol to but-1-yne (b) Ethane to bromoethane (c) Propene to 1-nitropropane (d) Toluene to benzylalcohol (e) Propene to propyne (f) Ethanol to ethyl fluoride (g) Bromomethane to propanone (h) But-1-ene to but-2-ene (i) 1-Chlorobutane to n-octane (j) Benzene to biphenyl.

88. Explain why (a) the dipole moment of chlorobenzene is lower than that of cyclohexyl chloride.(b) alkyl halides, though polar, are immiscible with water.(c) Grignard reagents should be prepared under anhydrous conditions.

89. Arrange the compounds of each set in order of reactivity towards SN2 displacement :

(a) 2-Bromo-2-methylbutane, 1-Bromopentane, 2-Bromopentane(b) 1-Bromo-3-methylbutane, 2-Bromo-2-methylbutane, 2-Bromo-3-methylbutane(c) 1-Bromobutane, 1-Bromo-2, 2-dimethylpropane, 1-Bromo-2-methylbutane, 1-Bromo-3-methylbutane

90. Write the structure of the major organic product in each of the following reactions :

91. Out of C6H5CH2Cl and C6H5CHClC6H5 which is more easily hydrolysed by aqueous KOH.92. The treatment of alkyl chlorides with aqueous KOH leads to the formation of alcohols but in presence of

alcoholic KOH, alkenes are the major products. Explain why ?93. Primary alkyl halide (A) C4H9Br reacted with alcoholic KOH to give compound (B). Compound (B) is

reacted with HBr to give (C) which is an isomer of (A). When (A) was reacted with Na metal, it gave acompound (D) C8H18 that was different from the compound formed when n-butyl bromide was reacted withsodium. Give the structural formula of (A) and write the equation for all the reactions.

94. What happens when(i) n-butyl chloride is treated with alcoholic KOH(ii) bromobenzene is treated with Mg in the presence of dry ether.

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(iii) Chlorobenzene is subjected to hydrolysis(iv) ethyl chloride is treated with aq. KOH(v) methyl bromide is treated with sodium in presence of dry ether.(vi) methyl chloride is treated with KCN ?

II. CBSE ProblemsCBSE 201095. Identify A and B in each of the following processes :

NaCN reduction(i) CH3CH2Cl A B

Ni/H2

CBSE 201196. Rearrange the compounds of each of the following sets in order of reactivity towards SN

2 displacement :(i) 2-Bromo-2-methylbutane, 1-Bromopentane, 2-Bromopentane(ii) 1-Bromo-3-methylbutane, 2-Bromo-2-methylbutane, 3-Bromo-2-methylbutane(iii) 1-Bromobutane, 1-Bromo-2, 2-dimethylpropane, 1-Bromo-2-methylbutane.

CBSE 201297. (i) Which one of the following compounds is more easily hydrolyzed by KOH and why ?

CH3CHClCH2CH3 or CH3CH2CH2Cl(ii) Which one undergoes SN2 substitution reaction faster and why ?

I or ClCBSE 201398. Give reasons for the following :

(i)Ethyl iodide undergoes SN2 reaction faster than ethyl bromide.

(ii) (±) 2-Butanol is optically inactive.(i) C - X bond length in halobenzene is smaller than C - X bond length in CH3 - X.

CBSE 201499. Which halogen compound in each of the following pairs will react faster in SN

2 reaction :(i) CH3Br or CH3I(ii) (CH3)3C - Cl or CH3 - Cl

CBSE 2015100. Which would undergo SN1 reaction faster in the following pair and why ?

CH3

CH3 - CH2- Br and CH3 - C - CH3

Br

CBSE 2016101. Which of the following two reactions is SN2 and why ?

CBSE 2017102. The following compounds are given to you: 2-Bromopentane, 2-Bromo-2-methylbutane, 1-

Bromopentane(a) Write the compound which is most reactive towards SN2 reaction.

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(b) Write the compound which is optically active.(c) Write the compound which is most reactive towards -elimination reaction.

CBSE - 2018(c) Write the structure of the alkene formed by dehydrohalogenation of 1-bromo4-methylcyclohexane withalcoholic KOH.

CBSE 2019103.

III. JEE MAINS/NEET PROBLEMS104. A primary alkyl halide would prefer to undergo ……….

a) (SN1 reaction (b) SN

2 reaction (c) α – Elimination (d) Racemisation105. Which of the following alkyl halides will undergo SN

1 reaction most readily ?a) (CH3)3C – F (b) (CH3)3C – Cl (c) (CH3)3C – Br (d) (CH3)3C – I

106. Reaction of C6H5CH2Br with aqueous sodium hydroxide follows ……a) SN1 mechanism (b) SN2 mechanismc) Any of the above two depending upon the temperature of reaction (d) Saytzeff rule

107. Which of the following compounds will give racemic mixture on nucleophilic substitution by OH- ion ?

a) I (b) I, II, III (c) II, III (d) I, III108. KI in acetone, undergoes 2N

S reaction with each of P, Q, R and S. The rates of the reaction varyas

JEE ADVANCED 2013a) P > Q > R > S (b) S > P > R > Q (c) P > R > Q > S (d) R > P > S > Q

109.A solution of (-) - 1 - chloro-1-phenylethane in toluene racemises slowly amount SbCl5 due to theformation of JEE MAINS 2013(a) carbocation (b) free radical (c) carbanion (d) carbene

110.Which of the following compounds will undergo racemisation when solution of KOH hydrolyses?

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AIPMT-2014a) (i) and (ii) (b) (ii) and (iv) (c) (iii) and (iv) (d) (i) and (iv)

111. In SN2 reaction, the correct order of reactivity for the following compounds:

CH3Cl, CH3CH2Cl, (CH3)2CHCl and (CH3)3CCl is JEE MAINS 2014a) CH2CH2Cl > CH3Cl > (CH3)2CHCl > (CH3)3CCl (b) (CH3)2CHCl > CH3CH2Cl > CH3Cl > (CH3)3 CClc) CH3Cl > (CH3)2CHCl > CH3CH2Cl > (CH3)2 CCl (d) CH3Cl > CH3CH2Cl > (CH3)2 CHCl > (CH3)3CCl

112. Which of the following is the most correct electron displacement for a nucleophilic reaction totake place. AIPMT-2015

113. In the reaction AIPMT-2016

X and Y are(1) X = 2-Butyne ; Y = 2-Hexyne (2) X = 1-Butyne; Y = 2-Hexyne(3) X = 1-Butyne; Y = 3-Hexyne (4) X = 2-Butyne ; Y = 3-Hexyne

114. The product of the reaction given below is: JEE MAINS-2016

115. 2-chloro-2-methylpentane on reaction with sodium methoxide in methanol yields:

JEE MAINS-2016(1) All of these (2) (a) and (c) (3) (c) only (4) (a) and (b)

116. The major product obtained in the following reaction is

JEE MAINS-2017(1) C6H5CH = CHC6H5 (2) (+) C6H5CH(O1Bu)CH2C6H6

(3) (-)C6H5CH(O1Bu)CH2C6H5 (4) () C6H5CH(O1BuCH2C6H5

117. The increasing order of the reactivity of the following halides for the SN1 reaction is :CH3CHCH2CH3 CH3CH2CH2Cl p-H3CO - C6H4 - CH2ClCl JEE MAINS-2017

(I) (II) (III)

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(1) (II) < (I) < (III) (2) (I) < (III) < (II) (3) (II) < (III) < (I) (4) (III) < (II) < (I)

118. For the following compounds, the correct statement(s) with respect of nucleophilic substitutionreactions is(are);

JEE ADVANCED-2017

(A) I and II follow SN2 mechanism as they are primary

(B) Reactivity order IV > I > III(C) I and III follow SN

1 mechanism as they form stable carbocation(D) Compound IV undergoes inversion of configuration

119. The major product of the following reaction is JEE MAINS-2018

Sol. (4)120. The compound A on treatment with Na gives B, and with PCl5 gives C. B and C react together to give

diethyl ether. A, B and C are in the order NEET-2018

Sol. (3)

121. The compound C7H8 undergoes the following reactions: NEET-2018

The product ‘C’ is(1) m-bromotoluene (2) o-bromotoluene (3) p-bromotoluene (4) 3-bromo-2,4,6-trichlorotolueneSol. (1)

122. Hydrocarbon (A) reacts with bromine by substitution to form an alkyl bromide which by Wurtz reactionis converted to gaseous hydrocarbon containing less than four carbon atoms. (A) is NEET-2018(1) CH = CH (2) CH2 = CH2 (3) CH4 (4) CH3 – CH3

Sol. (3)

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Hence the correct option is (3)IV. JEE ADVANCED PROBLEMS123. Tert-butyl chloride reacts with aq. NaOH by SN¹ mechanism while n-butyl chloride reacts by SN²

mechanism. Why ?

124. (a) Which of the following two compounds would react faster by SN² pathway : 1-bromobutane (OR)2-bromobutane.

(b)Allyl Chloride is more reactive than n-propyl Chloride towards nucleophilic substitution reactions.Explain.

125. R—Cl is hydrolysed to R—OH slowly but the reaction is rapid if a catalytic amount of KI is added tothe reaction mixture.

126. Why alkyl halides are generally not prepared in laboratory by free radical halogenation of alkanes ?127. Why does 2 bromopentane gives pent-2-ene as major product in elimination reaction ?128. Pentan-3-ol reacts with HBr to give a mixture of 3- and 2-bromopentane. Why ?129.Matching Type Questions

130. The major product of the following reaction isBrMe

F

NO2

PhSNa

dimethylformamide

131. An optically active 3-bromo-3-methyl hexane on hydrolysis givesa) 3-methyl-3-hexanol with retention of configuration(b) 3-methyl-3-hexanol with inversion of configurationc) a mixture of optically active 3-methyl-3-hexanol and 3-methyl-3-hexened) optically inactive 3-methyl-3-hexanol

132. What product(s) is (are) formed in the debromination of meso-2, 3-dibromobutane?a) Cis- and trans-2-butene in equal amounts (b) More cis-than trans-2-butenec) Only cis-2-butene (d) Only trans-2-butene

133. Predict the structure of the product in the following reaction

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Br

H Ph NaI―――――→ C

MeO H acetone

Ph134. The following reactions gives two products

Alc. KOH, C6H5 CH2 CHClC6H5

Write the structures of the products.

135. 1-Bromo-3-chlorocyclobutane when treated with two equivalents of Na, in the presence of ether, whichof the following will be formed ?

Br Cl

a) (b) (c) (d)WORK SHEET-4

TOPIC : HALOARENESI. NCERT PROBLEMS136. Although chlorine is an electron withdrawing group, yet it is ortho & para- directing in electrophilic

aromatic substitution reactions. Why ?137. p-Dichlorobenzene has higher melting point and lower solubility than o- and m- isomers. Discuss.138. How the following conversions can be carried out ?

a. Toluene to benzyl alcoholb. Benzene to 4-bromonitrobenzenec. Benzyl alcohol to 2-phenylethanoic acidd. Aniline to chlorobenzenee. Isopropyl alcohol to iodoformf. Chlorobenzene to p-nitrophenolg. Benzene to diphenylh. Aniline to phenylisocyanide

II. CBSE PROBLEMSCBSE-2017139.

CBSE-2018140. (a) Out of chlorobenzene and benzyl chloride, which one gets easily hydrolysed by aqueous NaOH and

why?(b) Write the structure of the product when chlorobenzene is treated with methyl chloride in the presenceof sodium metal and dry ether.

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II. JEE MAINS/AIPMT PROBLEMS141. The IUPAC name(s) of the following compound is(are) JEE ADVANCED-2017

142. Identify the compound Y in the following reactions.

143. Toluene reacts with a halogen in the presence of iron (III) chloride giving ortho and para halocompounds. The reaction isa) Electrophilic elimination reaction (b) Electrophilic substitution reactionc)Free radical addition reaction (d) Nucleophilic substitution reaction

144. Arrange the following compounds in the increasing order of their densities.

a) I < II < III < IV (b) I < III < IV < II (c) IV < III < II < I (d) II < IV < III < I145. Chlorobenzene is formed by reaction of chlorine with benzene in the presence of AlCl3 . Which

of the following species attacks the benzene ring in this reaction ?a) Cl- (b) Cl+ (c) AlCl3 (d) [AlCl4]-

146. The reaction of toluene with chlorine in the presence of iron and in the absence of light yields…….

Note : In the question 146 to 149 arrange the compounds in increasing order of rate of reactiontowards nucleophilic substitution

147.

a) I < II < III (b) III < II < I (c) I < III < II (d) III < I < II148.

a) I < II < III (b) I < III < II (c) III < II < I (d) II < III < I149.

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a) III < II < I (b) II < III < I (c) I < III < II (d) I < II < III150.

a) I < II < III (b) II < I < III (c) III < II < I (d) I < III < II151.

NEET-2013A is :a) HgSO4/H2SO4 (b) Cu2Cl2 (c) H3PO2 and H2O (d) H+/H2O

III. JEE ADVANCED PROBLEMS

152. Write the major product of the following reactions :CH3

AgCN | Anhyd. AlCl3(a) CH2 = CHBr (b) + CH3 ― C ― CH2 ― Br

Alcohol |CH3

ClNO2

153. (i) + Na2CO3 + H2O → C, Identify C

NO2

154. Explain why is Chlorobenzene difficult to hydrolyse than ethyl chloride ?155. Why preparation of aryl iodide by electrophilic substitution requires presence of an oxidising agent ?

Why can aryl flouride not be prepared by this method ?156. With Br2 in sunlight, toluene forms benzyl bromide and not o- and p-bromotoluene. Comment.157. Chloral hydrate is a stable compound although it has two OH groups attached to same carbon.

Comment.158. Reaction of p-Bromotoluene with NaOH at high temperature gives equal amounts of p- and m-cresols.

Explain.159. Which halogen best delocalises electron density to benzene ring ?160. Arrange the following in order of increasing ease towards nucleophilic substitution. 4-

chloronitrobenzene, chlorobenzene, 2, 4, 6-trinitrochlorobenzene, 2, 4-dinitrochlorobenzene.161. Give at least one characteristic test which can distinguish between

(i) n-Propyl bromide and isopropyl bromide(ii) Chlorobenzene and n-hexyl chloride(iii) Chlorobenzene and Cyclohexyl chloride.(iv) CH2 = CH ― CH2Br and CH3CH2CH2Br

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(v) Ethyl bromide and bromobenzene(vi) o-Chlorobenzyl bromide and o-bromobenzyl chloride.

162. In the following groups : OAc (I), OMe(II), OSO2Me(III) OSO2CF3(IV)the order of leaving group ability isa) I > II > III > IV (b) IV > III > I > II (c) III > II > I > IV (d) II > III > IV > I

163. Which of the following statement is true regarding the reaction of 2, 6-dimethylchlorobenzenewith aqueous NaOH ?a) It reacts only at high temperatureb) It does not react even at high temperature because it has two electro-withdrawing groups.c) It does not react even at high temperature because it has no ortho hydrogend) None of the above is correct.

164. Bottles containing C6H5I and C6H5CH2I lost their original labels. They were labeled A and B fortesting. A and B were separately taken in test tubes and boiled with NaOH solution. The endsolution in each tube was made acidic with dilute HNO3 and then some AgNO3 solution wasadded. Substance B gave a yellow precipitate. Which one of the following statements is true forthis experiment ?a) A was C6H5I (b) A was C6H5CH2I (c) B was C6H5I (d) Addition of HNO3 was unnecessary

AIEEE-2003165. Arrange the following compounds in decreasing order of their reactivity with sodium methoxide

in methanol at 50oC.Cl Cl Cl Cl

NO2

NO2

NO2

I II III IVa) II > III > IV > I (b) II = IV > III > I (c) II = III > I > IV (d) II = IV = III > I

166. The compound formed on heating chlorobenzene with chloral in the presence of conc. H2SO4 is:a) Hexachloroethane (b) DDT (c) Freon (d) Gammaxane AIEEE-2004

167. Fluorobenzene (C6H5F) can be synthesized in the laboratorya) by heating phenol with HF and KFb) from aniline by diazotization followed by heating the diazonium salt with HBF4

c) by direct fluorination of benzene with F2 gasd) by reacting bromobenzene with NaF solution AIEEE-2006

CH3 H CH3

168. CH3O NO2

H Cl CH3

On hydrolysis in aqueous acetone gives.CH3 H CH3

CH3O NO2 (K)

H OH CH3

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CH3 H CH3 CH3 H CH3

CH3O NO2 (L) CH3O NO2

OH H CH3 H CH3 OH (M)a) K and L (b) only K (c) K and M (d) only M

169. The structure of the major product formed in the following reaction is AIEEE-2006

a) (b) (c) (d)170. The major product of the following reaction is IIT 2011

(a) (b)

(c) (d)

1. The major product of the following reaction is JEE – MAINS 2019

Sol. (c)

UNIT : 10- HALOALKANES & HALOARENES · Alkyl halides, though polar, are immiscible with water. Why...

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