NEET AIPMT Chemistry Chapter Wise Solutions – Hydrocarbons

NEET AIPMT Chemistry Chapter Wise Solutions – Hydrocarbons

NEET AIPMT Chemistry Chapter Wise SolutionsPhysicsBiology

1. Which one is the correct order of acidity? (NEET 2017)

2.Predict the correct intermediate and product in the following reaction : (NEET 2017)

3.With respect to the conformers of ethane, which of the following statements is true? (NEET 2017)
(a) Bond angle changes but bond length remains same.
(b) Both bond angle and bond length change.
(c) Both bond angle and bond length remain same.
(d) Bond angle remains same but bond length changes.

4.Which of the following can be used as the halide component for Friedel-Crafts reaction? (NEET-II 2016)
(a) Chlorobenzene
(b) Bromobenzene
(c) Chloroethene
(d) Isopropyl chloride

5.In which of the following molecules, all atoms are coplanar? (NEET-II 2016)

6.pyrrole the electron density is maximum on (NEET-II 2016)

(a) 2 and 3
(b) 3 and 4
(c) 2 and 4
(d) 2 and 5

7.Which of the following compounds shall not produce propene by reaction with HBr followed by elimination or direct only elimination reaction? (NEET-II 2016)

8. In the given reaction, (NEET-II 2016)

9. The compound that will react most readily with gaseous bromine has the formula (NEET-II 2016)
(a)C₃H₆
(b) C₂H₂
(c) C₄H₁₀
(d) C₂H₄

10. The correct statement regarding the comparison of staggered and eclipsed conformations of ethane, is (NEET-I 2016)
(a) the eclipsed conformation of ethane is more stable than staggered conformation even though the eclipsed conformation has torsional strain
(b) the staggered conformation of ethane is more stable than eclipsed conformation, because staggered conformation has no torsional strain
(c) the staggered conformation of ethane is less stable than eclipsed conformation, because staggered conformation has torsional strain
(d) the eclipsed conformation of ethane is more stable than staggered conformation, because eclipsed conformation has no torsional strain.

11. Consider the nitration of benzene using mixed cone. H₂S0₄ and HN0₃. If a large amount of KHS0₄ is added to the mixture, the rate of nitration will be (NEET-I 2016)
(a) unchanged
(b) doubled
(c) faster
(d) slower.

12. The pair of electrons in the given carbanion, CH₃C≡C^–, is present in which of the following orbitals? (NEET-I 2016)
(a) sp²
(b) sp
(c) 2p
(d) sp³

13. In the reaction (NEET-I 2016)

X and Y are
(a) X= 2-Butyne, Y= 2-Hexyne
(b) X= 1-Butyne, Y= 2-Hexyne
(c) X= 1-Butyne, Y= 3-Hexyne
(d) X= 2-Butyne, Y= 3-Hexyne.

14. In the reaction with HCl, an alkene reacts in accordance with the Markovnikov’s rule to give a product 1-chloro-1 methylcyclohexane. The possible alkene is (2015)

15. 2,3-Dimethyl-2-butene can be prepared by heating which of the following compounds with a strong acid? (NEET-I 2016)

16. A single compound of the structure,

, is obtainable from ozonolysis of which of the following cyclic compounds? (2015,cancelled)

17. Given :

The enthalpy of hydrogenation of these compounds will be in the order as (2015,cancelled)
(a) II > III > I
(b) II > I > III
(c) I > II > III
(d) III > II > I

18. What products are formed when the following compound is treated with Br₂ in the presence of FeBr₃? (2014)

19. Identify Z in the sequence of reactions : (2014)

20. Which of the following organic compounds has same hybridization as its combustion product (C0₂)? (2014)
(a) Ethane
(b) Ethyne
(c) Ethene
(d) Ethanol

21. Which of the following compounds will not undergo Friedal-Craft’s reaction easily? (NEET 2013)
(a) Nitrobenzene
(b) Toluene
(c) Cumene
(d) Xylene

22. Which of the following chemical system is non aromatic? (Karnataka NEET 2013)

23. In the following reaction: (Karnataka NEET 2013)

product “P” will not give
(a) Tollen’s reagent test
(b) Brady’s reagent test
(c) Victor Meyer test
(d) Iodoform test

24. In the following reaction (2014)

25. Which of the following acids does not exhibit optical isomerism? (2012)
(a) Maleic acid
(b) α-amino acids
(c) Lactic acid
(d) Tartaric acid

26. Which of the following reagents will be able to distinguish between 1-butyne and 2-butyne? (Mains 2012)
(a) NaNH₂
(b) HCl
(c) 0₂
(d) Br₂

27. In the following the most stable conformation of n-butane is (2010)

28. Liquid hydrocarbons can be converted to a mixture of gaseous hydrocarbons by (2010)
(a) oxidation
(b) cracking
(c) distillation under reduced pressure
(d) hydrolysis.

29. The reaction of toluene with Cl₂ in presence of FeCl₃ gives X and reaction in presence of light gives Y. Thus, X and Y are (2010)
(a) X = Benzal chloride, Y = o-chlorotoluene
(b) X = m-chlorotoluene, Y = p-chlorotoluene
(c) X = o- and p-chlorotoluene, Y = Trichloromethyl benzene
(d) X = Benzyl chloride, Y = m-chlorotoluene

30. In a set of reactions, ethylbenzene yielded a product D.(2010)

31. Which of the following conformers for ethylene glycol is most stable? (Mains 2010)

32. The state of hybridisation of C2, C3, C5 and C6 of the hydrocarbon,

is in the following sequence (2009)
(a) sp³, sp², sp² and sp
(b) sp, sp², sp² and sp³
(c) sp, sp², sp³ and sp²
(d) sp, sp³, sp²and sp³

33. Which of the following compounds will exhibit cis-trans (geometrical) isomerism? (2009)
(a) Butanol
(b) 2-Butyne
(c) 2-Butenol
(d) 2-Butene

34. Benzene reacts with CH₃Cl in the presence of anhydrous AlCl₃ to form (2009)
(a) chlorobenzene
(b) benzyl chloride
(c) xylene
(d) toluene.

35. (2008)

36. In the hydrocarbon,

The state of hybridization of carbons 1, 3 and 5 are in the following sequence (2008)
(a) sp, sp², sp³
(b) sp³, sp², sp
(c) sp², sp, sp³
(d) sp, sp³, sp²

37. Predict the product Cobtained in the following reaction of 1-butyne. (2007)

38. Which of the compound with molecular formula C₅H₁₀ yields acetone on ozonolysis? (2007)
(a) 3-Methyl-1 -butene
(b) Cyclopentane
(c) 2-Methyl-1-butene
(d) 2-Methyl-2-butene

39. Which one of the following alkenes will react faster with H₂ under catalytic hydrogenation conditions? (2005)

40.Products of the following reaction : (2005)

(a) CH₃COOH + CO₂
(b) CH₃COOH+ HOOC.CH₂CH₃
(c) CH₃CHO + CH₃CH₂CHO
(d) CH₃COOH + CH₃COCH₃

41. Using anhydrous AlCl₃ as catalyst, which one of the following reactions produces ethylbenzene (PhEt)? (2004)
(a) H₃C – CH₂OH + C₆H₆
(b) CH₃ – CH = CH₂ + C₆H₆
(c) H₂C = CH₂ + C₆H₆
(d) H₃C-CH₃ + C₆H₆

42. Reaction of HBr with propene in the presence of peroxide gives (2004)
(a) isopropyl bromide
(b) 3-bromopropane
(c) allyl bromide
(d) n-propyl bromide.

43. The compound

on reaction with NaI0₄ in the presence of KMn0₄ gives (2003)
(a) CH₃COCH₃
(b) CH₃COCH₃ + CH₃COOH
(c) CH₃COCH₃ + CH₃CHO
(d) CH₃CHO + C0₂

44. Which one of the following is a free-radical substitution reaction? (2003)

45. The correct order of reactivity towards the electrophilic substitution of the compounds aniline (I), benzene (II) and nitrobenzene (III) is (2003)
(a) III > II > I
(b) II > III > I
(c) I < II >III
(d) I > II > III

46.(2002)

47.When CH₃CH₂CHCl₂ is treated with NaNH₂, the product formed is (2002)

48. In preparation of alkene from alcohol using Al₂0₃ which is the effective factor? (2001)
(a) Porosity of Al₂0₃
(b) Temperature
(c) Concentration
(d) Surface area of Al₂0₃.

49. The correct acidic order of the following is (2001)

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

50. Increasing order of electrophilic substitution for following compounds (2000)

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

51.In Friedel-Crafts reaction, toluene can be prepared by (2000)
(a) C₆H₆+ CH₃Cl
(b) C₆H₅Cl + CH₄
(c) C₆H₆+ CH₂Cl₂
(d) C₆H₆ + CH₃COCl

52. Which reagent converts propene to 1-propanol?(2000)
(a) H₂0, H₂S0₄
(b) B₂H₆, H₂0₂, OH^–
(c) Hg(OAc)₂, NaBH₄/H₂0
(d) Aq. KOH

53. Which is maximum stable? (2000)
(a) 1-Butene
(b) cis-2-Butene
(c) trans-2-Butene
(d) All have same stability.

54. 2-Butene shows geometrical isomerism due to (2000)
(a) restricted rotation about double bond
(b) free rotation about double bond
(c) free rotation about single bond
(d) chiral carbon.

55. Dihedral angle in staggered form of ethane is (2000)
(a) 0°
(b) 120°
(c) 60°
(d) 180°

56. When acetylene is passed through dil. H₂S0₄ in the presence of HgS0₄, the compound formed is (1999)
(a) acetic acid
(b) ketone
(c) ether
(d) acetaldehyde

57. In Friedel-Craft’s alkylation, besides AlCl₃ the other reactants are (1999)
(a) C₆H₆ + CH₃Cl
(b)C₆H₆+CH₄
(c) C₆H₆ + NH₃
(d) C₆H₆+CH₃C0Cl

58. Which of the following compounds will be most easily attacked by an electrophile? (1999, 1998)

59. Which’ one of these is not compatible with arenes? (1998)
(a) Electrophilic additions
(b) Delocalisation of π-electrons
(c) Greater stability
(d) Resonance

60. 2-Bromopentane is heated with potassium ethoxide in ethanol. The major product obtained is (1998)
(a) trans-2-pentene
(b) 1-pentene
(c) 2-ethoxy pentane
(d) 2-cis-pentene

61. Which of the following reaction is expected to readily give a hydrocarbon product in good yields? (1997)

62. (1997)

where M = Molecule and R = Reagent. M and R are
(a) CH₃CH₂OH and HCl
(b) CH₂ = CH₂ and heat
(c) CH₃CH₂Cl and NaOH
(d) CH₂Cl – CH₂OH and aq. NaHC0₃.

63. The cylindrical shape of an alkyne is due to (1997)
(a) two sigma C – C and one π C – C bonds
(b) one sigma C – C and two π C-C bonds
(c) three sigma C – C bonds
(d) three π C – C bonds.

64. In the commercial gasolines, the type of hydrocarbons which are more desirable is (1997)
(a) linear unsaturated hydrocarbon
(b) toluene
(c) branched hydrocarbon
(d) straight-chain hydrocarbon.

65. Among the following compounds (I-III) the correct reaction with electrophile is (1997)

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

66. The most stable conformation of n-butane is (1997)
(a) gauche
(b) staggered
(c) skew boat
(d) eclipsed.

67. Electrophile in the case of chlorination of benzene in the presence of FeCl₃ is (1996)
(a) Cl
(b) FeCl₃
(c) Cl⁺
(d) Cl^–

68. The reaction, CH₂ = CH – CH₃ + HBr—> CH₃CHBr – CH₃ is (1996)
(a) electrophilic substitution
(b) free radical addition
(c) nucleophilic addition
(d) electrophilic addition.

69. Which of the following has zero dipole moment? (1996)
(a) 1 -Butene
(b) 2-Methyl-1 -propene
(c) cis-2-Butene
(d) trans-2-Butene

70. The alkene R – CH = CH₂ reacts readily with B₂H₆ and the product on oxidation with alkaline hydrogen peroxides produces (1995)

71. One of the following which does not observe the anti-Markownikoff ‘s addition of HBr, is (1994)
(a) pent-2-ene
(b) propene
(c) but-2-ene
(d) but-l-ene

72. The reactive species in the nitration of benzene is (1994)
(a) NO₃
(b) HN0₃
(c) N0₂₊
(d) N0_2-

73.

The reagent is (1993)
(a) Na
(b) HCl in H₂0
(c) KOH in C₂H₅OH
(d) Zn in alcohol.

74. Reduction of 2-butyne with sodium in liquid ammonia gives predominantly (1993)
(a) cis-2-butene
(b) no reaction
(c) trans-2-butene
(d) n-butane.

75. A compound is treated with NaNH₂ to give sodium salt. Identify the compound. (1993)
(a) C₂H₂
(b) C₂H₂
(c) C₂H₂
(d) C₂H₄

76. Reactivity of hydrogen atoms attached to different carbon atoms in alkanes has the order (1993)
(a) tertiary > primary > secondary
(b) primary > secondary > tertiary
(c) both (a) and (b)
(d) tertiary > secondary > primary.

77. Which is the correct symbol relating the two Kekule structures of benzene? (1993)

78. Select the true statement about benzene amongst the following (1992)
(a) because of unsaturation benzene easily undergoes addition
(b) there are two types of C – C bonds in benzene molecule
(c) there is cyclic delocalisation of π-electrons in benzene
(d) monosubstitution of benzene gives three isomeric products.

79. Acetylenic hydrogens are acidic because (1989)
(a) sigma electron density of C – H bond in acetylene is nearer to carbon, which has 50% .s-character
(b) acetylene has only open hydrogen in each carbon
(c) acetylene contains least number of hydrogens among the possible hydrocarbons having two carbons
(d) Acetylene belongs to the class of alkynes with molecular formula, C_nH_2n-2

80. Which is the most suitable reagent among the following to distinguish compound (3) from rest of the compounds? (1989)
(1) CH₃ – C ≡ C – CH₃
(2) CH₃ – CH₂ – CH₂ – CH₃
(3) CH₃ – CH₂C = CH
(4) CH₃ – CH = CH₂
(a) Bromine in carbon tetrachloride
(b) Bromine in acetic acid
(c) Alk. KMn0₄
(d) Ammoniacal silver nitrate.

Answer Key

Explanations