NCERT Class 11 Chemistry Chapter 13 Hydrocarbons Multiple Choice Questions

NCERT Solutions For Class 11 Chemistry Chapter 13 Hydrocarbons Multiple Choice Questions

Question 1. Which one of the following alkenes produces a tertiary alcohol on acid-catalyzed hydration

1. CH₃—CH—CH=CH₂
2. CH₃—CH=CH—CH₃
3. (CH₃)₂C=CH₂
4. CH₃-CH=CH₂ 

Answer: 3. (CH₃)₂C=CH₂

Question 2. Only which one of the following compounds is obtained when excess of Cl₂ is passed through boiling toluene

Answer: 4

Question 3. The Friedel-Crafts reaction using MeCl and anhydrous AlCl₃ maybe carried out best with—

1. Benzene
2. Nitrobenzene
3. Toluene
4. Acetophenone

Answer: 3. Toluene

Due to its +1 and hyperconjugative effect, the —CH₃ group increases the electron density of the benzene ring. Thus, toluene becomes more susceptible towards electrophilic substitution reactions. So, Friedel-Crafts reaction using MeCl and anhydrous AlCl₃ is carried out best with toluene.

Question 4. Baeyer’s reagent is—

1. Alkaline potassium permanganate
2. Acidified potassium permanganate
3. Neutral potassium permanganate
4. Alkaline potassium manganate

Answer: 1. Alkaline potassium permanganate

Dilute aqueous solution of alkaline potassium permanganate (1-2%) is called Baeyer’s reagent

Question 5. 2-methylpropane monochloririation under photochemical conditions gives—1

1. 2-chloro-2-methylpropane as major product
2. (1 : 1) mixture of l-chloro-2-methylpropane and 2-chloro-2-methylpropane
3. 1-chloro-2-methylpropane as major product
4. (1:9) mixture of l-chloro-2-methylpropane and 2- chloro-2-methylpropane

Answer: 3. 1-chloro-2-methylpropane as major product

The ratio of A and B in the mixture is 5: 9, though 3° H is more active than 1° H, but in this case number of 1°H is 9 times than that of 3°H.

Question 6. Treatment of with  NaNH₂/liq.NH₃ gives—

Answer: 4.

The given reaction proceeds through the formation of the intermediate,  via the benzyne mechanism

Question 7. The best method for the preparation of 2,2-dimethylbutane is via the reaction of—

1. Me₃CBr and MeCH₂Br in Na/ ether
2. (Me₃C)₂CuLi and MeCH₂Br
3. (MeCH₂)₂CuLi and Me₃CBr
4. Me₃CMgI and MeCH₂I

Answer: 2. (Me₃C)₂CuLi and MeCH₂Br

Corey-House synthesis is the best method for preparing 2,2-dimethylbutane. The corresponding chemical reaction is given as

Question 8. The reaction of benzene with Me₃CCOCl in the presence of anhydrous AlCl₃ gives

Answer: 2

In this electrophilic substitution, removal of CO from the electrophile, acylium ion (Me₃CC⁺=O) results in a more stable tertiary butyl carbocation Me₃C⁺). Thus, C₆H₅CMe₃ is formed as the product.

Question 9. An optically active compound having molecular formula C₈H₁₆ on ozonolysis gives acetone (CH₃COCH₃) as one of the products. The structure of the compound is—

Answer: 2

Question 10. The reagents to carry out the following conversion are—

Answer: 4

Question 11.   Identify the correct method for the synthesis of the compound shown above from the following alternatives—

Answer: 2

Question 12. 1,4-dimethylbenzene on heating with anhydrous AlCl₃ and HCl produces—

1. 1,2-dimethylbenzene
2. 1,3-dimethylbenzene
3. 1,2,3-trimethylbenzene
4. Ethylbenzene

Answer: 21,3-dimethylbenzene

When 1,4-dimethylbenzene is heated with anhydrous AlCl₃ in the presence of HCl it undergoes isomerization to

Question 13.  The major product of the above reaction is—

Answer: 3

The major product in the given reaction can be determined by the following reaction mechanism

Question 14. Identify’X’ in the following sequence of reactions—

Answer: 2

Question 15. The major products obtained on ozonolysis of 2,3-dimethyl-1-butene followed by reduction with Zn and HO are—

1. Methanoic acid and 2-methyl-2-butanone
2. Methanal and 3-methyl-2-butanone
3. Methanal and 2,2-dimethyl-3-butanone
4. Methanoic acid and 2-methyl-3-butanone

Answer: 2. Methanal and 3-methyl-2-butanone

Question 16. Which one of the following compounds is not aromatic—

Answer: 2

Cyclooctatetraene is a tub-shaped compound and thus it is non-aromatic.

Question 17. An alkene on ozonolysis produces only one dicarbonyl compound. The alkene is—

Answer: 2

Question 18. The major product(s) obtained from the following reaction of1 mol of hexadeuteriobenzene is/are—

Answer: 1

Question 19. The isomerization of 1-butyne to 2-butyne can be achieved by treatment with—

1. Hydrochloric acid
2. Ammoniacal silver nitrate
3. Ammoniacal cuprous chloride
4. Ethanolic potassium hydroxide

Answer: 4. Ethanolic potassium hydroxide

Question 20. The major product(s) obtained in the following reaction is (are)—

Answer: 1 and 4

Question 21. The number of possible organobromine compounds which can be obtained in the allylic bromination of 1- butene with N-bromo succinamide is—

1. 1
2. 2
3. 3
4. 4

Answer: 4. 4

Question 22.

Species 1, 2, 3, and 4 respectively are—

1. Ethene, ethyne, ethanal, ethane
2. Ethane, ethyne, ethanal, ethene
3. Ethene, ethyne, ethanal, ethanol
4. Ehyne, ethane, ethene, ethanal

Answer: 1. Ethene, ethyne, ethanal, ethane

Question 23. The number of alkenes that can produce 2-butanol by the successive treatment of

1. B₂H₆ in tetrahydrofuran solvent and

2. Alkaline H₂O₂solution is

1. 1
2. 2
3. 3
4. 4

Answer: 1. 1

Question 24. CH₃C=CMgBr can be prepared by the reaction of—

1. CH₃ —C≡C—Br withMgBr₂
2. CH₃C≡CH with MgBr₂
3. CH₃C≡CH with KBr and Mg metal
4. HCH₃C≡CH with CHgMgBr

Answer: 4. HCH₃C≡CH with CHgMgBr

Question 25. Formaldehyde is one of the products obtained on ozonolysis of a compound. The presence of which of the following groups is proved by this observation—

1. Vinyl group
2. Isopropyl group CH₃
3. Acetylenic triple bond
4. Two ethylenic double bonds

Answer: 1. In ozonolysis, the vinyl group is converted into HCHO

Question 26. Which one of the following converts 2-hexyne into 2-hexene—

1. Li/NH₃
2. Pd/BaSO₄
3. LiAlH₄
4. Pt/H₂

Answer: 1. Li/NH₃

Question 27. The major organic compound formed by the reaction of 1,1,1-trichloroethane with silver powder is—

1. 2-butene
2. Ethene
3. Acetylene
4. 2-butyne

Answer: 4. 2-butyne

Question 28. In the reaction,  the product C is—

1. Acetyl chloride
2. Acetylene
3. Acetaldehyde
4. Ethylene

Answer: 4.  Ethylene

Question 29.  Which compound would give 5-keto-2-methyl hexanal OH upon ozonolysis?

Answer: 4

Question 30. The product (A) of the reaction given below CH₃ is—

Answer: 1

Question 31. The reaction of propene with HOCI(Cl₃ + H₂O) proceeds through the intermediate—

Answer: 1

Question 32. 2-chloro-2-methyl pentane in methanol yields on— reaction with sodium

1. Both 1 and 3
2. Only 2
3. Both 1 and 2
4. All of these

Answer: 4. All of these

Question 33. 3-methylpent-2-ene reacts with HBr in the presence of peroxide to yield an additional compound. How many three-dimensional isomers are possible for this addition compound— 

1. 2
2. 4
3. 6
4. 0

Answer: 2. 4

The resulting compound consists of two different asymmetric centers (shown by asterisks). Thus the number of three-dimensional isomers = 22 = 4

Question 34. Which one of the following compounds undergoes mononitration to yield a considerable amount of m product—

Answer: 1

During tire nitration of aniline, —NH₂ group gets protonated and form an anilinium ion ( —NH₃). The + —NH₃ group is deactivating and meta-orienting. Thus during the mono nitration of aniline, a significant amount of meta-product is obtained

Question 35. The major product of the following reaction is

Answer: 4

Due to the neopentyl type of structure, it cannot undergo S_N2 reaction

Question 36.  The trans-alkenes are formed by the reduction of alkynes with—

1. Na/liq. NH₃
2. H₂/Pd-C,BaSO₄
3. Sn/HCl
4. NaBH₄

Answer: 1. Na/liq. NH₃

Question 37.  The major products 1 and 3 are respectively

Answer: 3

Question 38. In the following reaction

Answer: 3.

Question 39. Which of the following reagents is used to distinguish between 1-butyne and 2-butyne—

1. HCl
2. OH
3. Br
4. NaNH₂

Answer: 4. NaNH₂

Question 40. Which one of the following compounds is most reactive towards electrophilic-nitration reaction—

1. Toluene
2. Benzene
3. Benzoic acid
4. nitrobenzene

Answer: 1. Toluene

Due to +1 and the hyperconjugation effect of —CH₃ group, toluene is the most reactive toward electrophilic nitration reaction

Question 41. Which of the following compounds will not undergo Friedel-Crafts reaction easily

1. Toluene
2. Cumene
3. xylene
4. Nitrobenzene

Answer: 4. Nitrobenzene

Groups like nitro ( —NO₂) withdraw electrons from the benzene ring and deactivate the ring to such an extent that it cannot be attacked by the relatively weak electrophile. So, nitrobenzene does not undergo FriedelCraft reaction

Question 42. The radical  is aromatic because it has—

1. 6p-orbitals and 7 unpaired electrons
2. 6p-orbitals and 6 unpaired electrons
3. 7p- orbitals and 6 unpaired electrons
4. 7p-orbitals and 7 impaired electrons

Answer: 3. 7p- orbitals and 6 unpaired electrons

The given free radical is aromatic because it contains a benzene ring having 6n -electrons which remain delocalised. The seventh odd electron does not play any role in determining the aromaticity of the
free radical.

Question 43. Some meta-directing substituents in aromatic substitution are given. Which is most deactivating— 

1. COOH
2. —NO₂
3. —C=N
4. —SO₃H

Answer: 2. —NO₂

Due to -I and -R effect, —NOa is a highly deactivating and —CN, —SO₃H and moderately deactivating meta-orienting group

Question 44. Nitrobenzene, on reaction with cone. HNO₃/H₂SO₄ at 80-100°C forms one of the following products—

1. 1,4-dinitrobenzene
2. 1,2,4-trinitrobenzene
3. 1,2-dinitrobenzene
4. 1,3-dinitrobenzene

Answer: 4. 1,3-dinitrobenzene

Question 45. Identify the sequence of reactions

1. CH₃(CH₂)₃-O-CH₂CH₃
2. (CH₃)₂CH—O—CH₂CH₃
3. CH₃(CH₂)₄—O-CH₃
4. CH₃CH₂-CH(CH₃)-O-CH₂CH₃

Answer: 1. CH₃(CH₂)₃-O-CH₂CH₃

Question 46. Which of the following organic compounds has the same hybridization as its combustion product (CO₂) —

1. Ethane
2. Ethyne
3. Ethene
4. Ethanolic

Answer: 2. Ethyne

C-atom in both ethyne and CO₂ is sp -sp-hybridized

Question 47. The oxidation of benzene by V₂O₅ in the presence of air produces—

1. Benzoic anhydride
2. Maleic anhydride
3. Benzoic acid
4. Benzaldehyde

Answer: 2. Maleic anhydride

Question 48. Which of the following is not the product of dehydration of

Answer: 2

  does not form because the intermediate carbonation  i.e is highly stable, so it does not undergo rearrangement

Question 49. In the reaction with HCI, an alkane reacts by Markownikoff’s rule, to give a product 1-chloro-1 methylcyclohexane. The possible alkane is—

Answer: 3

Question 50. Because of the absence of torsional strain, staggered conformation is more stable than eclipsed conformation.

1. The correct statement regarding the comparison of staggered and eclipsed conformations of ethane is— the staggered conformation of etha HPgi*less stable than eclipsed conformation because staggered hasÿirsional strain
2. The eclipsed conformation of ethane is more stable than staggered conformation because eclipsed conformation has no torsional strain
3. The eclipsed conformation of ethane is more stable than staggered conformation even though the eclipsed conformation has torsional strain
4. The staggered conformation of ethane is more stable than eclipsed conformation because staggered conformation has no torsional strain

Answer:  4. The staggered conformation of ethane is more stable than eclipsed conformation because staggered conformation has no torsional strain

Question 51. Consider the nitration of benzene using a mixed cone. H₂SO₄ and HNO₃.If a large amount of KH₂SO₄ is added to the mixture, the rate of nitration will be—

1. Faster
2. Slower
3. Unchanged
4. Doubled

Answer: 2. Slower

⇒ \(\mathrm{HNO}_3+2 \mathrm{H}_2 \mathrm{SO}_4 \rightleftharpoons \mathrm{H}_3 \stackrel{\oplus}{\mathrm{O}}+\stackrel{\oplus}{\mathrm{N}} \mathrm{O}_2+2 \mathrm{HSO}_4^{\ominus}\)

Addition of KHSO₄ increases the concentration of

H₂SO^–₄ and due to the common ion effect, the production of

NO⁺₂ decreases which slows down the nitration process

Question 52. In the reaction

X and 7 are—

1. X = 1 -butyne; Y- 3 -hexyne
2. X = 2 -butyne; Y = 3 -hexyne
3. X = 2 -butyne; 7=2 -hexyne
4. X = 1 -butyne; 7=2 -hexyne

Answer: 1.  X = 1 -butyne; Y- 3 -hexyne

Question 53. Which of the following compounds shall not produce propene by reaction with HBr followed by elimination or direct only elimination reaction—

1. CH₃ CH₂CH₂OH

2. CH₃ CH₂CH₂Br

3. CH₂=C=O

Answer: 2. CH₃ CH₂CH₂Br

Question 54. In the given reaction the product P is

Answer: 2

Question 55. The compound that will react most readily with gaseous bromine has the formula—

1. C₂H₂
2. C₄H₁₀
3. C₂H₄
4. C₃H₆

Answer: 4. C₃H₆

The reaction undergoes via a radical pathway. Among the given alkenes, propene can form the most stable radical intermediate and thus it undergoes the reaction faster than other alkenes.

Question 56. Which one is the correct order of acidity—

Answer: 1.

For a C-atom in the hybridised state, acidic character increases with increase of the s-character. Again the presence alkyl group reduces the acidic property due to its +1 effect. Hence the order of acidity of the given compounds:

Question 57. Nitration of aniline in a strong acidic medium also gives  -m-nitroaniline because

1. In acidic (strong) medium aniline is present as an anilinium ion
2. Inspite of substituents nitro group always goes to only m -position
3. In absence of substituents nitro group always goes to m -m-position
4. In electrophilic substitution reactions amino group is meta-directive

Answer: 1. In acidic (strong) medium aniline is present as an anilinium ion

Question 58. The compound C₇H₈ undergoes the following reactions   The Product ‘C

 is___________

1. p -bromotoluene
2. m – bromotoluene
3. 3-bromo-2,4,6-trichlorotoluene
4. o -bromotoluene

Answer: 2. m – bromotoluene

Question 59. Hydrocarbon (d) reacts with bromine by substitution to form an alkyl bromide which by Wurtz reaction is converted to a gaseous hydrocarbon containing less than four carbon atoms. A is—

1. CH₄
2. HC≡CH
3. CH₃ – CH₃
4. CH₂ = CH₂

Answer: 1.CH₄

Question 60. Identify the major products P, Q and R in the following sequence of reactions 

Answer: 1

Question 61. When trans-butene is reacted with Br₂ the product formed is

3. Meso-compounds

4. Both 2 And 3

Answer: 4. Both 2 And 3

With trans-but-2-ene, the product of Br₂ addition is Br optically inactive due to the formation of symmetric me-so-compounds

Question 62. What is ‘A’in the following—

Answer: 3

Question 63.  Which of the following aromatic—

Answer: 4

Any planar cyclic system containing (4n + 2)n electrons and having a single cyclic n -electron cloud encompassing all the carbon atoms in the ring is aromatic

Question 64. Which of the following alkenes will give the same product by any method out of hydration, hydroboration-oxidation and oxymercuration-demarcation—

Answer: 2. CH₃CH=CHCH₃

CH₃CH=CHCH₃ is symmetrical and gives the same product by any of the given methods adopted

Question 65. Which of the following species is not aromatic

1. Benzene
2. Cyclooctatetraenyl dianion
3. Tropyliumion
4. Cyclopentadienyl cation

Answer: 4.  Cyclopentadienyl cation

On applying the Huckel’s rule, [(4n + 2)n -electron] system

Question 66. What will be compound A in the following reaction—

Answer: 1.

Question 67. Identify X 

Answer: 3

Strong electron releasing group ( — OCH₃) generally predominates over the deactivating group ( —NO₂). Thus, o – and p – products will be formed. Due to steric hindrance ortho-product will be formed in lesser amount than para-product

Question 68. Which Brof the following compounds is aromatic in nature—

Answer: 1,3 and 4

1: Due to the presence of (4n + 2)πe in; it follows Huckel’s rule and therefore,it is aromatic. Due to the presence of an extra lone pair of electrons in , total electron comes out to be 4πe . Thus, it is antiaromatic.

3: In although it is cyclic and has conjugated Huckel’s (4n + 2)πe rule is not followed here and also ring is notplanar. Hence,it is non-aromatic.

4: It has 6πe in conjugation but not in the ring, hence it is non-aromatic

Question 69. In the given reaction  ‘A’is________

Answer: 2

Question 70. What is the decreasing order of boiling points for the following compounds

1. 1> 2 > 3
2. 2 >3> 1
3. 1 > 3 > 2
4. 3 > 2 > 1

Answer: 1.1> 2 > 3

Question 71. The correct order of decreasing boiling points of the following hydrocarbons is—

1. n-butane

2. 2-methylbutane

3. n-pentane

4. 2,2- dimethylpropane

1. (1) > (2) > (3) > (4)
2. (2) > (3) > (4) > (1)
3. (4) > (3) > (2) > (1)
4. (3) > (2) > (4) > (1)

Answer: 4. (3) > (2) > (4) > (1)

Question 72. Addition of HBr with 1-butane (CH₃CH₂CH=CH₂) forms a mixture consisting of 1,2 and 3

In the mixture—  

1. 1 and 2 exist as major products while 3 as minor product
2. 2 exists as major product and 3 as minor products
3. 2 exists as a minor product whileI and 3 as major products
4. 1 and II exist as minor products while 3 as majorproduct

Answer:  1and 2 exist as major products while 3 as minor product

Question 73. Which of the following alkenes does not exhibit geometrical isomerism—

1. 1 and 2 exist as major products while 3 as minor product
2. Exists as major product while and 3 as minor products
3. 2 exists as minor products while 3 as major products
4. 1 and 2 exist as minor products while 3 a major product

Answer:  4. 1 and 2 exist as minor products while 3 as major product

Question 74. When a mixture of concentrated aqueous solutions of sodium salts of two monocarboxylic acids is electrolysed, a mixture of ethane, propane and butane is obtained at the anode. The two acids are
—
CH₂COOH, CH₃CH₂COOH

1. CH₃COOH, HCOOH
2. CH₃CH₂COOH,CH₃CH₂CH₂COOH
3. (CH₃)₂CHCOOH, CHCOOH

Answer:  1. CH₂COOH, CH₃CH₂COOH

Question 75.  The products formed when CH₃I, CH₃CHO and CH₃CH₂COOH are respectively reduced by HI in presence of red phosphorus are—

1. CH₃CH₃, CH₃CH₃, CH₃CH₂CH₃
2. CH₄, CH₃CH₃, CH₃CH₂CH₃
3. CH₃CH₂CH₃, CH₄, CH₃CH₃
4. CH₄, CH₃CH₂CH₃, CH₃CH₂CH₂CH₃

Answer: 2. CH₄, CH₃CH₃, CH₃CH₂CH₃

Question 76. The decreasing order of boiling points of isomeric pentanes is—

1. n-pentane > isopentane > neopentane
2. Isopentane > n-pentane > neopentane
3. Neopentane > isopentane > n-pentane
4. n-pentane > neopentane > isopentane

Answer: 1. n-pentane > isopentane > neopentane

Question 77. The reactivity of different types of hydrogen during halogenation of alkanes follows the order—

1. 2°H > 1°H > 3°H
2. 1°H >2°H > 3°H
3. 2°H > 3°H > 1°H
4. 3°H > 2°H > 1°H

Answer: 4. 3°H > 2°H > 1°H

Question 78. The correct IUPAC name of the monochord derivative that forms as the major product during chlorination of 3-ethyl pentane is—

1. 1-chloro-3-ethyl pentane
2. 2-chloro-3-ethyl pentane
3. 3-chloro-3-ethyl pentane
4. 3-ethyl-3-chloroethane

Answer:  3. 3-chloro-3-ethyl pentane

Question 79. Which of the following symmetrical alkanes is not prepared by Wurtz reaction—

1. Ethane
2. Butane
3. 2,2,3,3-tetramethyl butane
4. 2,3-dimethylbutane

Answer: 3. 2,2,3,3-tetramethyl butane

Question 80. The octane numbers of 2,2,4-trimethylpentane isooctane) and n-pentane are respectively—

1. 50,50
2. 100,0
3. 0,100
4. 50,0

Answer: 2. 2. 100,0

Question 81. The increasing order of octane numberis

1. n-alkane < branched alkane < cycloalkane < aromatic hydrocarbon
2. Aromatic hydrocarbon < cycloalkane < branched alkane < n-alkane
3. Cycloalkane < branched alkane < aromatic hydrocarbon < n-alkane
4. Aromatic hydrocarbon < cycloalkane < n-alkane < branched alkane

Answer: 1. n-alkane < branched alkane < cycloalkane < aromatic hydrocarbon

Question 82. The amount of oxygen (in mole) required for the combustion of1 mol hydrocarbon (CÿHÿ,) is—

1. \(\left(x+\frac{y}{4}\right)\)
2. \(\left(y+\frac{x}{4}\right)\)
3. (x+y)
4. \(\left(x+\frac{y}{2}\right)\)

Answer: 1. \(\left(x+\frac{y}{4}\right)\)

Question 83. Which of the following compounds on reacting with Grignard reagent (RMgX) does not form an alkane—

1. CH₃C=CH
2. CH₃CH₂OCH₂CH
3. C₂H₅OH
4. H₂O

Answer:  2. CH₃CH₂OCH₂CH

Question 84. The change in the hybridisation state of carbon in ethane duringits combustion is—

1. sp³→sp
2. sp²→sp³
3. sp→sp³
4. sp→sp²

Answer: 1. sp³→sp

Question 85. The intermediate formed during chlorination of methane in diffused sunlight is

1. \(\stackrel{\oplus}{\mathrm{C}} \mathrm{H}_3\)
2. :CH₂
3. ^•CH₃
4. :C^–H₃

Answer:   3. ^•CH₃

Question 86. The product formed when 2 equivalent ofmetallic sodium reacts with l-bromo-3-chlorocyclobutane in ether medium is

Answer: 4

Question 87. Which of the following compounds are not formed when a mixture of ethyl iodide and n-propyl iodide is subjected to Wurtz reaction—

1. Butane
2. Propane
3. Pentane
4. Hexane

Answer: 2. Propane

Question 88. In Kolbe’s electrolytic process which of the following compounds does not lead to the formation of an alkane—

1. CH₃COONa
2. CH₃CH₂COONa
3. HCOONa
4. CH₃CH₂CH₂COOK

Answer: 3. HCOONa

Question 89. —I + Zn +I —R—>R —R + Znl2; The reaction is—

1. Frankland reaction
2. Grignard reaction
3. Wurtzreaction
4. Corey-House synthesis

Answer: 1. Frankland reaction

Question 90. Which of the following statements is not true—

1. Alkanes are non-polar compounds
2. Alkanes are insoluble in polar solvents like water
3. Among isomeric alkanes, n-alkane has the lowest boiling point
4. Higher alkanes (> C₁₇) are hard like wax

Answer: 3. Among isomeric alkanes, n-alkane has the lowest boiling point

Question 91. The reagent which is not used in the preparation of propene from 1-bromopropane is

1. Water/KOH
2. Ethanol/ C₂H₅O^–Na⁺
3. Ethanol/KOH
4. Tert-butylalcohol/(CH₃)₃CO^–K⁺

Answer: 1. Water/KOH

Question 92. The reducing agent which is not used to prepare RCH=CHR from RC=CR is—

1. Na/liq.NH₃
2. H₂/Lindlar’s catalyst
3. B₂H₆ /tetrahydrofuran
4. H₂/PtorPd

Answer: 4. H₂/PtorPd

Question 93. Decreasing order of stability of the given carbanions is—

1. CH₃—C≡^–C:

2. H —C=C^–:

3. CH₃—:C^–H₂

1. 1 > 2 > 3
2. 2 > 1> 3
3. 3 > 2 > 1
4. 3 > 1 > 2

Answer: 2. 2 > 1> 3

Question 94. Baeyer’s reagent which is used in the Baeyer’s test for detecting ethylenic unsaturation is—

1. An acidic solution of potassium permanganate
2. A dilute alkaline solution of potassium permanganate
3. An aqueous solution of bromine
4. A solution ofbrominein acetic acid

Answer: 2. A dilute alkaline solution of potassium permanganate

Question 95. Which of the following compounds on ozonolysis forms C02 along with other products—

1. CH₂=C=CHCH₃
2. CH₃CH=CH—CH=CH₂
3. CH₃CH=CH—CH=CH₂
4. CH₃CH=CH—CH=CH₂

Answer: 1. CH₂=C=CHCH₃

Question 96. Which of the following compounds on ozonolysis forms a carbonyl compound

1. CH₃CH=CH₂
2. (CH₃)₂C=CHCH₃
3. (CH₃)₂C=C(CH₃)₂
4. CH₂=CH —CH=CH₂

Answer:  3. (CH₃)₂C=C(CH₃)₂

Question 97. Alkene which forms CH₃COCH₂CH₂CH₂CH₂COCH₃ on ozonolysis is

Answer:  4.

Question 98. An alkene, on ozonolysis forms HCHO, CH₃COCHO and CH₃CHO. The alkene is—

1. CH₂=C(CH₃)—CH=CHCH₃
2. CH₂=C(CH₃) —CH₂ —CH=CH2
3.  CH₃—CH=CH—CH=CHCH₃
4. CH₃—CH=CH—CH₂—CH=CH₂

Answer: 1. CH₂=C(CH₃)—CH=CHCH₃

Question 99. CH₃COCOCH₃, CH₃COCHO and OHC—CHO are formed due to the ozonolysis of o-xylene. The ratio in which the compounds are formed—

1. 3:2:1
2. 2:3:1
3. 1:2:3
4. 3:1:2

Answer: 3. 1:2:3

Question 100. Which of the following reactions occurs following Markownikoff’s rule

Answer:  4

Question 101. For which of the following reaction, Markownikoff’s rule is applicable—

Answer:  3

Question 102. The intermediate which is formed in the first step of the reaction between CH₃CH=CH₂ and HBr is a

1. Carbanion
2. Carbocation
3. Free radical
4. Carbene

Answer: 2.

Question 103. Among all the HX compounds, only HBr reacts with CH₃CH=CH₂ in the presence ofperoxide according to antiMarkownikoff’s rule. This is because, in case of HBr, the third and fourth steps

1. CH₃—CH=CH₂ + Br→CH₃CHCH2Br and

2. CH₃CHCH₂Br + H —Br→CH₃CH₂CH₂Br + Br )

1. The third step is exothermic while the fourth step is endothermic
2. Both the steps are exothermic
3. The third step is endothermic while the fourth step is exothermic and the fourth steps
4. Both the steps are endothermic

Answer: 2. Both the steps are exothermic

Question 104. Which of the given compounds on reacting with HBr forms the same product in the presence and absence of peroxide—

Answer: 3

Question 105. The order of acidity of ethyne (1), ethane (2) and ethene (3) is

1.  2 >1 >3
2. 1 >3 >2
3. 1 >2 >3
4. 2 >3 >1

Answer: 3. 1 >2 >3

Question 106. The compound which does not form a red precipitate on reacting with ammoniacal cuprous chloride solution is—

Answer: 2

Question 107. The reagent that cannot be used to distinguish between ethylene and acetylene is—

1. Ammoniacal cuprous chloride
2. Br₂/H₂O
3. Dil. H₂SO₄/Hg²⁺
4. Ammoniacal silvernitrate solution

Answer:  2. Br₂/H₂O

Question 108. Two compounds, when subjected to ozonolysis separately,  CH₃COCH₂CH₃(2mol)  The compounds are— each form and

1. Enantiomers
2. Diastereomers
3. Metamers
4. Tautomers

Answer:  1. Enantiomers

Question 109. The compound Y in the given reaction is –

Answer: 1

Question 120. The addition of HBr occurs most readily for—

Answer: 4.

Question 121.   In this reaction a is

Answer: 1.

Question 122. Which of the following compounds undergoes hydrolysis to form propyne-

1. Al₄C₃
2. Mg₂C₃
3. B₄C
4. La₄C₃

Answer: 2.Mg₂C₃

Question 123. Hydration of alkenes (except ethylene) in presence of acid produce—

1. 1° alcohols
2. 2° or 3° alcohols
3. Mixture of1° and 2° alcohols
4. Mixture of 2° and 3° alcohols

Answer: 2. 2° or 3° alcohols

Question 124. Cyclohexanone   react with witting reagents (Ph3P—CHR) to form—

Answer: 3

Question 125. When ethylene gas is passed through an aqueous solution of NaCl and Br₂ the compound whose formation is not possible is—

Answer: 3

Question 126.  Here , X is

1. Cyclobutane
2. Cyclopropane
3. Cyclopentane
4. Cyclohexane

Answer: 2. Cyclopropane

Question 127. Which of the following alkynes cannot be converted into a terminal alkyne when heated with NaNH₂/ paraffin—

1. CHC₃=CCH₃
2. CH₃CH₂C=CCH₂CH₃
3. CH₃CH₂CH₂C=CCH₂CH₃
4. (CH₃)₂CHC=CCH(CH3)₂

Answer: 4. (CH₃)₂CHC=CCH(CH₃)₂

Question 128. Correct order of decreasing reactivity of the given com¬ pounds towards electrophilic substitution reaction is –

1. 3 > 1 > 2 > 4
2. 4 > 1 > 2 > 3
3. 1 > 2 > 3 > 4
4. 2 > 1 > 3 > 4

Answer: 1. 3 > 1 > 2 > 4

Question 129. Number of monochloride derivatives possible for diphenylmethane

1. 4
2. 8
3. 7
4. 18

Answer: 1. 4

Question 130. The compound which is formed in excess when Cl₂ reacts with toluene in presence of FeCl₃ is—

1. Benzyl chloride
2. o – and p -chlorotoluene
3. m -chlorotoluene
4. Benzoyl chloride

Answer: 2. o – and p -chlorotoluene

Question 131. The major product obtained when undergoes monobromination(with Fe Br)is 

Answer: 2

Question 132. Polysubstitution occurs for which of the following reactions—

Answer: 2

Question 133.   compound X is________________

Answer: 2.

Question 134. The compound which is most reactive in case of electrophilic attack is-

Answer: 1

Question 135. Benzene does not form additional compound because—

1. It has ring structure
2. Its double bond is verystrong
3. It has 6 equivalent h-atoms
4. Its aromatic stability is lost

Answer: 4. Its aromatic stability is lost

Question 136. In strong acidic and alkaline medium, p-aminophenol exists in (X) and (Y) forms respectively

Thus, in acidic and alkaline medium, electrophilic substitution occurs at-

1. a,c
2. a,d
3. b,c
4. b,d

Answer: 1. a,c

Question 137. In electrophilic substitution reaction of benzene—

1. The first step is exothermic but the second step is endothermic
2. The first step is endothermic but the second step is exothermic
3. Both the steps are exothermic
4. Both the steps are endothermic

Answer: 2.  The first step is endothermic but the second step is exothermic

Question 138. The method suitable for converting benzene into propylbenzene is 

Answer: 3

Question 139. An aromatic compound of molecular formula C₈H₁₀ reacts with a mixture of concentrated HNO₃ and concentrated H₂SO₄ to form a mononitro compound. The structural formula of C₈H₁₀ is

Answer: 4

Question 140. Nitrobenzene is prepared from benzene by using conc. HNO₃ and cone. H₂SO₄ . In the nitrating mixture, nitric acid acts as a/an—

1. Base
2. Acid
3. Reducing agent
4. Catalyst

Answer: 1.  Base

Question 141. On passing excess Cl₂(g) through boiling toluene, the only compound that forms is—

Answer: 4

Question 142. Which of the given participates in Friedel-Crafts reaction—

Answer: 4

Question 143. In which of the following compounds the ring on the left side undergoes electrophilic substitution reaction—

Answer: 4

Question 144. The increasing order of the rate of nitration reaction of the following compounds is- 

1. 2 < 3 < 1 < 4 < 5
2. 4 < 5 < 1 = 3 < 2
3. 4 < 1 = 3 < 5 < 2
4. 1 < 3 < 2 < 5 < 4

Answer: 2.  4 < 5 < 1 = 3 < 2

Question 145. The major product formed in the following reaction is-

Answer: 4.

Question 146.

Answer: 2

Question 147. The acidity of which of the following compounds is quite high compared to the rest of the given compounds—

Answer: 3

Question 148. Bromination takes place most rapidly in—

Answer: 2

Question 149. 

Answer: 1

Question 158. Benezene when subjected to ozonolysis (03 followed by Zn/H₂O ) forms—

Answer: 1

Question 159. BHC is a/an—

1. Fertiliser
2. Insecticide
3. Explosive
4. Solvent

Answer: 2.  Insecticide

Question 160. (CH₃)₃CMgCl reacts with D₂O to form—

1. (CH₃)₃CD
2. (CH₃)₃OD
3. (CD₃)₃CD
4. (CD₃)₃OD

Answer: 1.  (CH₃)₃CD

Question 161. Which two compounds undergo ozonolysis to produce CH₃CHO, CH₃COCHO and HCHO —

Answer: 2, 3

Question 162. Among the following oxidation reactions of methane, which two are controlled oxidation reactions —

Answer: 3,4

Question 163. Which of the following alkenes undergo ozonolysis to form a mixture of two ketones—

Answer: 3,4

Question 164. Which of the following compounds form the same product with HBr in presence and absence of peroxide—

1. Cyclohexene
2. But-2-ene
3. Hex-3-ene
4. 1-methylcyclohexene

Answer: 1,2,3

Question 165. The compounds which react with dilute H₂SO₄ in the presence of HgS04 to form methyl ketone are—

Answer: 2,3,4

Question 166. The compounds which only form glyoxal when subjected to ozonolysis are—

1. Ethene
2. Benzene
3. Toluene
4. Ethyne

Answer: 2,4

Question 167. In which of the following compounds, nitration take place at the para-position—

Answer: 2,4

Question 168. Which of the following groups are deactivating but ortho-J para-orienting—

1. —Cl
2. —CH=CH—COOH
3. —N=O
4. -CF₃

Answer: 1,2,3

Question 169. Which two of the following groups are used to block a definite position in the benzene ring-

1. -SO₃H
2. — CH₃
3. — CF₃
4. —CMe₃

Answer: 1,4

Question 170. Which of the following reactions do not occur—

Answer: 1,2

question 171. Which of the following reactions do not take place easily in the benzene ring—

1. Polyadenylation
2. Polynitration
3. Poly sulphonation
4. Polyalkylation

Answer: 1,2,3

Question 172. Polybrominated takes place in which of the given cases—

Answer: 2,3

Question 173. In which of the following reactions, toluene is obtained— When methanol reacts with PhMgBr

1. Na-salt of o -toluic acid is heated with sodalime
2. p-cresol is distilled in presence of Zn dust
3. Benzyl alcohol is heated in the presence of red
4. Phosphorous and concentrated HI

Answer: 2,3,4

Question 174. In which of the reactions, ferf-butylbenzene is formed—

Answer: 1,3,4

Question 175. Which on ozonolysis forms a mixture of two ketones—

Answer: 1,3,4

Question 176. Which of the following compounds undergo chlorination to produce a type of monochloroalkane—

Answer: 1,2,4

Question 177. Which undergoes nitration reaction faster than benzene-

1. C₆H₅CH₃
2. C₆H₅NHCOCH₃
3. C₆H₅COOH
4. C₆H₅CHO

Answer: 1,2

Question 178. Which undergoes nitration reaction slower than benzene—

1. C₆H₅CH=CHCOOH
2. C₆H₅CH=CH-NO₂
3. C₆H₅CMe₃
4. C₆H₅OCH₃

Answer: 1,2

Question 179. Which of the following σ -complexes are more stable than the cr -complex of benzene—

Answer: 1,4

Question 180. Which of the following compounds has 10 isomers—

1. CI₂C₆H₃NH₂
2. CH₃C6H4NO₂
3. BrClC6H₃CHO
4. O₂NC₆H₃BrCH₃

Answer: 3,4

Question 181. The compounds which get oxidised by alkaline KMn04 to form benzoic acid are —

1. Toluene
2. Ethylbenzene
3. Tert-butyl benzene
4. Benzyl chloride

Answer: 1,2,4

Question 182. Which of the following can be used to distinguish between ethylene and acetylene—

1. Bromine water
2. Ammoniacal Cu₂Cl₂
3. Ammoniacal AgNO solution
4. Dilute alkaline kmnO₄ solution

Answer: 2,3

Question 183. In which two compounds, homolytic cleavage of the C—Ha bond takes place most readily—

Answer: 1,2

Question 184. The compounds which do not participate in Friedel Crafts reaction are —

Answer: 1,2,4

Question 185. Which of the following cannot be used as an alkylating reagent in Friedel-Crafts reaction—

Answer: 2,4

Question 186. Which of the following facts are correct

Answer: 1,3

Question 190. Markownikoff’s rule is applicable for which of the following reactions—

Answer: 1,2