ISOMERISM

EDUDIGM Be sincere, not serious

1. Which is not found in alkenes [AIIMS 1982; RPMT 1999]

(a) Chain isomerism (b) Geometrical isomerism (c) Metamerism (d) Position isomerism

2. Diethyl ether and methyl n-propyl ether are [MP PET 1994; AFMC 1999; MP PMT 2002]

(a) Position isomers (b) Functional isomers (c) Metamers (d) Chain isomers

3. Name the compound, that is not isomer with diethyl ether [IIT 1981; CPMT 1989; MADT Bihar 1995]

(a) n-propylmethyl ether (b) Butane-1-ol (c) 2-methylpropane-2-ol (d) Butanone

4. n-propyl alcohol and isopropyl alcohol are examples of [MP PMT 1994]

(a) Position isomerism (b) Chain isomerism (c) Tautomerism (d) Geometrical isomerism

5. An alkane forms isomers if the number of least carbon atom is [CPMT 1976; BHU 1985, 89]

(a) 1 (b) 2 (c) 3 (d) 4

6. Diethyl ether is not associated with which one of the these isomers [AFMC 1993]

(a) Butanoic acid (b) Methyl propionate (c) Stereoisomerism (d) None of these

7. How many primary amines are possible for the formula NHC 114 [MNR 1995]

(a) 1 (b) 2 (c) 3 (d) 4

8. Number of structural isomers of OHC 104 are

[CPMT 1983, 84, 89, 91; MADT Bihar 1984; MNR 1984; MP PET 1997; Pb. PMT 1999]

(a) 3 (b) 6 (c) 7 (d) 10

9. The number of isomers for the compound with molecular formula BrClFIC2 is [IIT Screening 2001]

(a) 3 (b) 4 (c) 5 (d) 6

10. An isomer of ethanol is [DPMT 1982, 88; CPMT 1973, 75, 78, 84; IIT 1986; BHU 1984, 85; EAMCET 1993;

MP PET 1995; RPET 1999; BHU 2000; AFMC 2002]

(a) Methanol (b) Dimethyl ether (c) Diethyl ether (d) Etthylene glycol

11. Which pair represents chain isomer [RPMT 2000]

(a) 23CHClCH and ClCHClCH 22 (b) n-propyl alcohol and isopropyl alcohol

(c) 2-methyl-1 propanol and 2-Methyl-2-propanol (d) 2-methyl butane and neopentane

12. The isomerism shown by n-butyl alcohol and isobutyl alcohol is [RPMT 2000]

(a) Metamerism (b) Chain (c) Position (d) Stereo

13. Total number of isomers of 146HC are [IIT 1987; DPMT 1983; CPMT 1991; MNR 1990; MP PET 1995; UPSEAT 2001]

(a) 4 (b) 5 (c) 6 (d) 7

14. 223 CHCHCHCH and 33 CHCHCHCH show [MP PAT 1996]

(a) Chain isomerism (b) Position isomerism (c) Functional isomerism (d) Metamerism

15. The number of possible alcoholic isomers for OHC 104 are [DPMT 1984; MNR 1986]

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

16. How many isomers are possible for OHC 84 [MNR 1992; UPSEAT 2001, 02]

(a) 3 (b) 4 (c) 5 (d) 6

17. The isomer of diethyl ether is [CPMT 1975]

(a) CHOHCH 23)( (b) OHCCH 33)( (c) OHHC 73 (d) CHOHHC 252 )(

18. Isomers have essentially identical [CBSE 1988;MP PMT 1983, 86]

(a) Structural formula (b) Chemical properties (c) Molecular formula (d) Physical properties

19. The total number of isomers formed by 105HC is [Bihar MEE 1996]

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

(e) None of these

20. n-butane and isobutane are examples of

(a) Chain isomers (b) Geometrical isomers (c) Position isomers (d) Tautomers

21. The number of possible isomers for compound BrClHC 232 is [MP PMT 1999]

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

22. Two compounds have the structural formulae 323 CHCHOCH and OHCHCHCH 223 . The above is an example of

(a) Metamerism (b) Functional isomerism (c) Positional isomerism (d) Chain isomerism

23. The functional isomer of ethyl alcohol is [MP PMT 2002]

(a) 33OCHCH (b) 33COCHCH (c) COOHCH 3 (d) CHOCHCH 23

24. Number of isomers of 104 HC is [CBSE 1996; AFMC 1997; RPMT 2002]

(a) 2 (b) 3 (c) 4 (d) Isomerism not exist

25. Which is the example of branch isomerization [NCERT 1976]

ISOMERISM

EDUDIGM Be sincere, not serious

(a) CC

C

CC|

and C

C

C

CC|

| (b)

C

C

C

CC|

| and C

C

C

C

C|

|

(c) CCCC

C and

C

C

CCC|

| (d) CCCC and

C

CCC|

26. NHC 97 has how many isomeric forms that contain a benzene ring [CPMT 1997, 99]

(a) 4 (b) 5 (c) 6 (d) 7

27. The number of possible structural isomers for a compound with the molecular formula 167 HC is [DCE 2001]

(a) 8 (b) 9 (c) 10 (d) 12

28. The number of possible isomers of butene are [IIT 1982; MP PMT 1985; MADT Bihar 1995; Kerala (Engg.) 2002]

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

(e) 6

29. Number of isomers of molecular formula 222 BrHC are [CPMT 1987]

(a) 1 (b) 2 (c) 3 (d) 0

30. Which of the following pairs is an example of position isomerism

(a) 3223 CHCHCHCH and 3

3

|3 CH

CH

CHCH (b) 223 CHCHCHCH and 33 CHCHCHCH

(c) OHCHCH 23 and 33 CHOCH (d)

3

3

3

|

|3

CH

CH

CHCCH and 32223 CHCHCHCHCH

31. Examine the following three pairs of possible isomers

Now state whether the pairs represent identical compounds or different isomers

(a) All three pairs represent different compounds

(b) (ia) and (ib) are identical; (iia) and (iib) are identical; and (iiia) and (iiib) are identical

(c) (ia) and (ib) are isomers; (iia) and (iib) are identical; and (iiia) and (iiib) are isomers

(d) (ia) and (ib) are identical; (iia) and (iib) are identical; and (iiia) and (iiib) are isomers

32. Tautomerism is exhibited by [CBSE 1997; KCET 2002]

(a) CNOCH 33)( (b) NHCH 23)( (c) 23CNOR (d) 22 NORCH

33. Only two isomers of monochloro product is possible of [IIT 1986, 2004; Pb. PMT 2000]

(a) n-butane (b) 2, 4-dimethyl pentane (c) Benzene (d) 1-methyl propane

(e) 2-methyl propane

34. Keto-enol tautomerism is found in [IIT 1988; MADT Bihar 1995]

(a) H

O

CCH||

65 (b) 56

||

65 HC

O

CCH (c) 3

||

65 CH

O

CCH (d) 3

||

2

||

65 CH

O

CCH

O

CCH

35. The tautomeric form which is less stable is called

(a) Anion form (b) Cation form (c) Labile form (d) All of the above

36. The total number of possible isomeric trimethyl benzene is [MP PET 1997]

(a) 2 (b) 3 (c) 4 (d) 6

37. Glucose and fructose are [AMU (Engg.) 1999]

(a) Optical isomers (b) Functional isomers (c) Position isomers (d) Chain isomers

38. Total number of isomers of a disubstituted benzene compound is

(a) 1 (b) 2 (c) 3 (d) 4

39. The compound OHC 104 can show [IIT 1981; MP PET 2000]

(a) Metamerism (b) Functional isomerism (c) Positional isomerism (d) All of the above

40. How many isomers of OHHC 115 will be primary alcohols [CBSE 1992]

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

41. Which of the following pairs are not isomeric compounds

(a) Ethyl ethanoate and methyl propanoate (b) Butanone and butanal

Cl

Cl

(ia) (iia)

CH

3

CH

3 (iiia)

COOH

HOOC

Cl

Cl (ib) (iib)

CH

3

H3

C

(iiib)

COOH

COOH

ISOMERISM

EDUDIGM Be sincere, not serious

(c) Ethoxy propane and propoxy ethane (d) Methoxy methane and ethanol

42. Tautomerism is exhibited by [IIT 1998]

(a) (b)

(c) (d)

43. NCHC 56 and CNHC 56 exhibit which type of isomerism [CPMT 1997; AFMC 1995, 97]

(a) Position (b) Functional (c) Dextro isomerism (d) Metamerism

44. Isomers of propionic acid are [MP PMT 2002]

(a) 52 HHCOOC and 33COOCHCH (b) 52 HHCOOC and 373 COOCHHC

(c) 33COOCHCH and OHHC 73 (d) OHHC 73 and 33COCHCH

45. Choose the pair of chain isomer [RPMT 2000]

(a) 23CHBrCH and BrBrCHCH 22 (b) 1-propanol and 2-propanol

(c) Neo-pentane and isopentane (d) Diethyl ether and methyl-n-

propyl ether

46. How many structural isomers are possible for a compound with molecular formula ClHC 73 [CBSE 2001]

(a) 2 (b) 5 (c) 7 (d) 9

47. Which of the following compounds shows tautomerism [MP PET 2001]

(a) HCHO (b) CHOCH 3 (c) 33COCHCH (d) HCOOH

48. What is the maximum number of open chain structures possible for 84 HC [MP PET 2001]

(a) 2 (b) 3 (c) 4 (d) 1

49. Nitrophenol, ))(( 246 NOOHHC can have

(a) No isomer (only a single compound is possible) (b) Two isomers

(c) Three isomers (d) Four isomers

50. Which of the following compounds will show metamerism [KCET 1996]

(a) 523 HCOOCCH (b) 5252 HCSHC (c) 33 CHOCH (d) 523 HCOCH

51. The number of possible isomers of the compound with molecular formula OHC 87 is [BHU 2001]

(a) 3 (b) 5 (c) 7 (d) 9

52. Which will gives colour with 3FeCl

(a) (b)

O

HCHCOC

OH

CCH||

52

|

3 (c) (d)

53. )C()B()A( 6236431063 OHCOHCOHCOH

A, B and C all give iodoform test. A and B also form oximes, A is neutral but B

gives 2CO with 3NaHCO . Hence A can be

(a) 5223 HCOOCCOCHCH (b) 3223 COOCHCOCHCHCH (c) 3223 COCOOCHCHCHCH (d)

3

3|

3

CH

COOCHCHCOCH

54. B

(III) (II)

, (I)2

||3

2

H

KOHICOOHCH

O

CCH , B is

(a) 22 )(COOHCH (b) COOHCH 3 (c) OCO

COCH 2 (d) None of these

55. (C)

(B)(A)

Na/ether115

light2125 ClHCClHC . Only one structure of B is possible. (A), (B) and (C) are

(a)

3

3

3

|

|2

3

3

2

|

|3

3

3

2

|

|3

3

3

3

|

|3

CH

CH

CHCCH

CH

CH

CHCCH

CH

CH

ClCHCCH

CH

CH

CHCCH

(b)

33

33

32

|

|

|

|233

3

2

|

|33

3

2

|

3

CHCH

CHCH

CHCHCCCHCHCH

CH

Cl

CHCCHCH

CH

CHHCCH

(c) Both are correct

CH = CH – OH

O

O

OH OH NH2

O O

O

OH

ISOMERISM

EDUDIGM Be sincere, not serious

(d) None of these

56. An organic compound of formula OHC nn 2 has an acyclic skeleton with no carbon-carbon multiple bonds. If the molecular

weight of the compound is 58, which of the following may be the structure of the compound

(a) 32 CHOCHCH (b) 32 CH

O

CHCH (c) 33 CHCOCH (d) OHCHCHCH 22

57. DC)B()(A//

84Pt/

64232 HCNZnOHOH

HCHC . D has chiral carbon and can be hydrolysed to lactic acid. Hence A,

is

(a) 33 CCHCCH (b) 22 CHCHCHCH (c) (d)

58. OHC 63 (A) does not reduce Tollen’s reagent, does not give iodoform test, but reacts with HI. A can be

(a) 33COCHCH (b) CHOCHCH 23 (c) 32 CHOCHCH (d)

O

CHCHCH 23

59. benzene)(trichloro

(Y)

enzene)(dichlorob

(X)3362246 ClHCClClHC

Fe. Only one structural isomer of Y is formed. Hence, (X) is

(a) o-isomer (b) p-isomer (c) m-isomer (d) None of these

60. 246 ClHC (A), dichlorobenzene is chlorinated (without using directive influence rule) to give 336 ClHC (B). Which are correct

statements

(a) ortho-isomer of A will form two types of B (b) meta-isomer of A will form three types of B

(c) para-isomer of A will form one type of B (d) All of the above

61. 62lime soda

263464

(A)

HCOHCOHC ,(A) is

(a) 23 )(COOHCHCH (b) COOHCH

COOHCH

2

2

| (c) Both (a) and (b) (d) None of these

62. 32

||

2

||

3 CHOCH

O

CCH

O

CCH A, ( D is catalyst). A is

(a) 52

|||

3 HC

O

COCH

OH

CCH (b) 52

|||

3 HC

OH

OCCH

O

CCH (c) 52

|||

3 HCO

O

CCH

OD

CCH (d) Formation of A is not

possible

63. Which is most volatile isomer of nitrophenol

(a) o– (b) m– (c) p– (d) Equal

64. HCN and HNC are …. isomers

(a) Functional (b) Tautomers (c) Chain (d) Position

65. The molecular formula of diphenyl methane, is 1213HC . How many structural isomers are possible

when one of the hydrogen is replaced by a chlorine atom [CBSE 2004]

(a) 8 (b) 7 (c) 6 (d) 4

66. Compounds whose molecules are superimposable on their mirror images even though they contain asymmetric carbon

atoms or chiral centres are known as

(a) Enantiomers (b) Racemers (c) Mesomers (d) Conformers

67. Which one of the following will not show geometrical isomerism [MP PMT 2003]

(a)

Br

Cl

CC

H

CH 3

(b)

Br

Cl

CC

CH

CH

3

3

(c)

Br

Cl

CC

D

H

(d)

Br

Cl

CC

Br

Cl

68. Butene-2 exhibits [DPMT 2002]

(a) Metamerism (b) Geometrical isomerism (c) Optical isomerism (d) None of these

69. Geometrical isomers differ in [CBSE 2002]

(a) Position of atoms (b) Length of carbon

(c) Spatial arrangement of atoms (d) Position of functional group

70.

H

CH

CC

H

CH 33

and

3

3

CH

H

CC

H

CH

exhibit which isomerism [MP PET 2002]

CH3

D+

CH2

ISOMERISM

EDUDIGM Be sincere, not serious

(a) Position isomerism (b) Geometrical isomerism (c) Optical isomerism (d) Functional isomerism

71. Racemic mixture is formed by mixing two [AIEEE 2002]

(a) Isomeric compounds (b) Chiral compounds (c) Meso compounds (d) Optical isomers

72. Glucose has optical isomers [DCE 2001]

(a) 8 (b) 12 (c) 16 (d) Cannot be predicted

73. Which of the following is a chiral compound [AIIMS 2002]

(a) Hexane (b) Methane (c) n-butane (d) 2, 3, 4-trimethyl hexane

74. Disymmetric object is one which is [Kerala (Engg.) 2002]

(a) Superimposable on its mirror image (b) Non-superimposable on its mirror image

(c) Optically inactive (d) Achiral

75. When isomers have the same structural formula but differ in relative arrangement of atoms or groups are called

[CPMT 2000; KCET (Med.) 2000]

(a) Mesomers (b) Stereoisomers (c) Optical isomers (d) Geometrical mesomers

76. A similarity between optical and geometrical isomerism is that [AIEEE 2002]

(a) Each forms equal number of isomers for a given compound (b) If in a compound one is present

then so is the other

(c) Both are included in stereoisomerism (d) They have no similarity

77. Optical isomerism arises due to the presence of [RPMT 2000]

(a) An asymmetric carbon atom (b) Centre of symmetry

(c) Axis of symmetry (d) Plane of symmetry

78. Which of the following statements is not true about enantiomers [DCE 2001]

(a) They have same physical properties

(b) They have different biological properties

(c) They have same chemical properties towards chiral compounds

(d) None of these

79. Chirality of carbon compound is because of its [Kerala (Med.) 2002]

(a) Tetrahedral nature of carbon (b) Monovalent nature of carbon

(c) Divalent nature of carbon (d) Trivalent nature of carbon

80. Which one of the following contains asymmetric carbon atom [IIT 1989; Roorkee 2000]

(a)

BrCl

HH

HCCH|

|

|

| (b)

ClH

HH

ClCCH|

|

|

| (c) H

H

H

C

H

H

CH|

|

|

| (d)

HH

OHBr

CHCCH 3

|

|

|

|

81. An organic compound exhibits optical isomerism when [CPMT 1971, 78, 81; MP PET 1999]

(a) Four groups linked to carbon atom are different (b) Three groups linked to carbon atom are different

(c) Two groups linked to carbon atom are different (d) All the groups linked to carbon atom are same

82. Stereoisomers which are not the mirror images of one another are called [RPMT 2000]

(a) Enantiomers (b) Mesomers (c) Tautomers (d) Diastereoisomers

83. Which one is asymmetric C-atom [Roorkee 1995]

(a)

Br

CHCHCH|

223 (b) 3

3

||3 CH

CH

CH

Br

CHCH (c) 3|

23 CH

Br

CHCHCH (d) 32

3

2

|

|3 CHCH

CH

Br

CHCCH

84. Which one of the following objects is ‘achiral’

(a) Letter P (b) Letter F (c) Ball (d) A pair of hand

85. The following compound can exhibits

COOH

H

C

H

CH

CC

CH

CH

3

3

3

[IIT 1995; DCE 2000]

(a) Tautomerism (b) Optical isomerism

(c) Geometrical isomerism (d) Geometrical and optical isomerism

86. cis and trans 2-butene are [BHU 1998]

(a) Conformational isomers (b) Optical isomers (c) Position isomers (d) Geometrical isomers

87. Which of the following compounds will exhibit geometrical isomerism [IIT Screening 2000]

(a) 1-phenyl-2-butene (b) 3-phenyl-1-butene (c) 2-phenyl-1-butene (d) 1, 1-Diphenyl-1-propene

88. Reason for geometrical isomerism by 2-butene is [CBSE 2000]

ISOMERISM

EDUDIGM Be sincere, not serious

(a) Chiral carbon (b) Free rotation about single bond

(c) Free rotation about double bond free (d) Restricted rotation about double bond

89. Which one of the following exhibits geometrical isomerism [NCERT 1979; DPMT 1984; CBSE 1990; AIIMS 2004]

(a)

33 CH

H

CC

CH

H

(b)

H

H

CC

H

CH 2

(c)

H

H

CC

CH

CH

3

3

(d)

H

H

C

CH

H

C

H

CH

3

|

|

|

90. Which of the following will not lose asymmetry on reduction with 4LiAlH [Roorkee 2000]

(a)

CHO

CHCH

CHCHCHOH

2

322 (b)

3

32

2

CH

CHCH

CHOHCCH (c)

3

2

CH

CHC

COOHCHOH (d)

CHO

NHCH

NCCH

22

3

91. Which of the following will show geometrical isomerism [CPMT 2001]

(a) 33 CHCHCHCH (b) 2323 )()( CHCCCH (c) 2323 )()( CHCCCH (d) 233 )(CHCCHCH

92. Which one of the following pairs represents the stereoisomerism [AIIMS 1992]

(a) Geometrical isomerism, position isomerism (b) Geometrical isomerism, conformational isomerism

(c) Optical isomerism, geometrical isomerism (d) Optical isomerism, metamerism

93. Meso-tartaric acid is optically inactive due to the presence of [AIIMS 1982; MP PMT 1987]

(a) Molecular symmetry (b) Molecular asymmetry (c) External compensation (d) Two asymmetric C-atoms

94. It is possible to distinguish between optical isomers by [Manipal MEE 1995; AFMC 1995]

(a) Infrared spectroscopy (b) Mass spectrometry (c) Melting point determination (d) Polarimetry

95. Geometrical isomerism is not possible in [CPMT 2000]

(a) Propene (b) 3-hexene (c) Butenedioic acid (d) Cyclic compound

96. Which one of the following compounds shows optical isomerism [MP PET 1990]

(a) 323 CHCHCHClCH (b) 3223 CHCHCHClCHCH

(c) 3222 CHCHCHClCH (d) 322 CHCHClCH

97. The property by virtue of which a compound can turn the plane polarised light is known as [BHU 1979]

(a) Photolysis (b) Phosphorescence (c) Optical activity (d) Polarization

98. The number of optical isomers of an organic compound having n asymmetric carbon atoms will be [MP PET 1994]

(a) 12n (b) 2n (c) n2 (d) 12n

99. Which of the following exhibits optical isomerism [BHU 1980; NCERT 1983; AIIMS 1992; MNR 1993; MP PMT 1990, 94]

(a) Butanol-1 (b) Butanol-2 (c) Butene-1 (d) Butene-2

100. Which of the following cannot be given to exemplify chiral structure [JIPMER 1997]

(a) A shoe (b) A screw (c) A screw driver (d) All of the above

101. Which of the following can exhibit cis-trans isomerism [CBSE 1989]

(a) HC CH (b) ClCH = CHCl (c) COOHCHClCH ..3 (d) ClCHClCH 22

102. The number of enantiomers of the compound CH3CHBrCHBrCOOH is [AIIMS 1997]

(a) 0 (b) 1 (c) 3 (d) 4

103. Optically active isomers but not mirror images are called [MP PET 1999]

(a) Enantiomers (b) Mesomers (c) Tautomers (d) Diastereoisomers

104. Chirality is lost when

(a)

OH

CHCOOHCH|

3 is heated (b) is heated

(c) COOH

OH

CHCHCH|

23 is heated (d)

COOHCH

CHCOOHCH

2

|3 is heated

105. and are …. isomer

(a) Position (b) Optical (c) Geometrical (d) Diastereomer

106. The prefixes syn and anti are used to denote [DPMT 2002]

(a) Structural isomers (b) Conformational isomers (c) Geometrical isomers (d) Optical isomers

107. Which will form geometrical isomers

O

CH3

HOOC

Cl

Cl

Cl

Cl

Cl

Cl

ISOMERISM

EDUDIGM Be sincere, not serious

(a) (b) NOHCHCH 3 (c) (d) All of the above

108. -D-glucose and -D glucose have a specific rotation of o112 and o19 respectively. In aqueous solution the rotation

becomes o52 . This process is called

(a) Inversion (b) Racemisation (c) Mutarotation (d) Enolisation

109. Glucose and mannose are [AIEEE 2004]

(a) Epimers (b) Anomers (c) Ketohexoses (d) Disaccharides

110. Which of the following will have a mesoisomer also [AIEEE 2004]

(a) 2, 3-dichloropentane (b) 2, 3-dichlorobutane

(c) 2-chlorobutane (d) 2-hydroxy propanoic acid

111. 32

|

|3 CH

CHO

CH

H

CCH In this compound chiral carbon has configuration

(a) R (b) S (c) Both (a) and (b) (d) None of these

112. Which is/are correct statements about P and Q

(a) P is cis- and Q is trans- (b) P is Z and Q is E

(c) P is R and Q is S (d) P and Q are same structure

113. ClCCH

BrCCl

3|| is

(a) trans (b) Z (c) Both (a) and (b) (d) None of these

114.

COOH

HHO

OHH

COOH

configuration at 1C and 2C atoms are

(a) d and d (b) l and l (c) R and R (d) R and S

115.

H

OHMe

Et

* has chiral centre (*). It is

(a) R (b) S (c) Both (a) and (b) (d) None of these

116. Which are correct statements

(a) and are enantiomers

(b) 32

|

|3 CHCH

Cl

H

CCH and

3

32

|

|

CH

CHCH

HCCl are same structures

(c) Argol (sodium potassium tartrate) will show optical isomerism

(d) CHOCH 3 on reaction with HCN gives racemic mixture

117. 3/ NHLiA, A is

(a) cis-2-butene (b) trans-2-butene (c) Isobutene (d) 1-butene

118. I and II are

(a) Achiral-identical mirror images (b) Chiral-enantiomers

(c) Geometrical isomer (each separately) (d) Racemic mixture

119. Number of chiral carbon atoms in is

(a) 2 (b) 3 (c) 4 (d) 1

120. 444 OHC can be

Q P

1

2

O

O

O

O

H

H

CH3

CH3

(I)

H

H

CH3

CH3

(II)

Cl

CH3

ISOMERISM

EDUDIGM Be sincere, not serious

(a) A cyclic ester (b) cis- and trans- dibasic acid

(c) gem- , -unsaturated dibasic acid (d) All of the above

121. In which case chiral carbon is generated

(a) OHHCNCOCHCH 3

33 (b) OHHCNCHOCH 3

3

(c) OHHCNCOCOOHCH 3

3 (d)

122. The optically active tartaric acid is named as D – (+) – tartaric acid because it has a positive [IIT 1999]

(a) Optical rotation and is derived from D-glucose

(b) pH in organic solvent

(c) Optical rotation and is derived from D – (+) – glyceraldehyde

(d) Optical rotation when substituted by deuterium

123.

:

: 3||

2

O

CHCCH and

::

3|

2

O

CHCCH are [CBSE PMT 2002]

(a) Resonating structures (b) Tautomers (c) Geometrical isomers (d) Optical isomers

124. The compound, whose stereo-chemical formula is written below, exhibits x geometrical isomers and y optical isomers

2

3

CH

H

CC

H

CH

. The values of x and y are

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

125. Maximum enolisation takes place of

(a) 33COCHCH (b) CHOCOCHCH 23 (c) 323 COCHCOCHCH (d)

126. are

(a) Enantiomers (b) Diastereomers (c) Geometrical isomers (d) Same structure

127. Which are correct statements

(a) Methyl malonic acid is converted into propanoic acid on heating

(b) Succinic acid forms succinic anhydride on heating

(c) 3-hydroxy propanoic acid forms acrylic acid on heating

(d) COOHCH

O

CCH 2

||

3 forms acetone on heating

128. By Fischer projections glyceryl aldehyde is represented as

(a)

CHO

OHCH

OHCH

2

(b)

OHH

OHCH

CHO

C 2

|

(c) Both (a) and (b) (d) None of these

129. How many asymmetric carbon atoms are present in

(i) 1, 2-dimethyl cyclohexane (ii) 3-methyl cyclopentene (iii) 3-methyl cyclohexene

(a) Two, one, one (b) One, one, one (c) Two, none,two (d) Two, none, one

130. )(C)B()(Alime Soda

263464 OHCOHC , C is hydrocarbon occupying 0.75 litre per g approximately. Hence A and B are

(a) Methyl malonic acid, propanoic acid (b) Succinic acid,succinic anhydride

(c) Maleic acid, maleic anhydride (d) Tartaric acid, propanoic

anhydride

131. Select correct statements

(a) and both give colour with neutral 3FeCl solution

(b) 2-pentanone and 3-pentanone are position as well as metamers

O

H H3C

H CH3

CH3 H

CH3 H

CH3 H

H H3C

OH OH

ISOMERISM

EDUDIGM Be sincere, not serious

(c) Product formed when benzaldehyde reacts with hydroxylamine shows geometrical isomerism

(d) 1, 2-dibromocyclohexane shows geometrical and optical isomerism

132. Which of the following has Z-configuration

(i) HCCH

HCCHC

3

5273

|| (ii) HCCH

HCCHC

3

7352

|| (iii) BrCCl

FCH

|| (iv) BrCCl

HCF

||

(a) Only (i) (b) Only (iii) (c) Both (i) and (iii) (d) Both (i) and (iv)

133. An enantiomerically pure acid is treated with racemic mixture of an alcohol having one chiral carbon. The ester formed

will be

[IITS 2003]

(a) Optically active mixture (b) Pure enantiomer (c) Meso compound (d) Racemic mixture

134. The process of converting d form to l or vice-versa is known as

(a) Walden inversion (b) Resolution (c) Racemisation (d) None of these

135. Which is incorrect about enantiomorphs

(a) They have different biological properties (b) They have identical physical properties

(c) They can rotate the plane polarised light (d) They have same shape of crystal

136. Diastereomers can be separated by

(a) Simple distillation (b) Fractional crystallisation (c) Electrophoresis (d) None of these

137. The least number of carbon atoms for an alkane to show stereoisomerism is

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

138. Which of the following is threo isomer

I

|

|

|

Y

A

ZCX

ZCX

II

|

|

|

Y

A

ZCX

XCZ

III

|

|

|

X

A

YCX

XCZ

(a) Only I (b) Only II (c) Only III (d) All of the above

139. In the reaction CNOHCHCHHCNCHOCH )(33 a chiral centre is produced. Thus product would be

[CBSE 1995; Pb. PMT 1998]

(a) Meso compound (b) Racemic mixture (c) Laevorotatory (d) Dextrorotatory

140. meso-Tartaric acid is optically inactive due to the presence of

(a) Molecular symmetry (b) Molecular asymmetry (c) External compensation (d) Two asymmetric C-atoms

141. Which of the following compound exhibit stereoisomerism [IIT Screening 2002]

(a) 2-Methylbutene-1 (b) 3-Methylbutyne-3 (c) 3-Methylbutanoic acid (d) 2-Methylbutanoic acid

142. Which of the following pairs of compounds are enantiomers [CBSE 2003]

(a)

3

3

CH

OHH

HHO

CH

and

3

3

CH

HHO

HHO

CH

(b)

3

3

CH

HHO

OHH

CH

and

3

3

CH

OHH

HHO

CH

(c)

3

3

CH

HHO

OHH

CH

and

3

3

CH

HHO

HHO

CH

(d)

3

3

CH

HHO

OHH

CH

and

3

3

CH

OHH

OHH

CH

143. The correct statement about the compounds A, B and C is

(A)

3

COOH

OHH

OHH

COOCH

(B)3COOCH

OHH

OHH

COOH

(C)3COOCH

HHO

OHH

COOH

[IIT 1997]

(a) A and B are identical (b) A and B are diastereomers (c) A and C are enantiomers (d) A and B are enantiomers

144. Which of the following may exist in enantiomorphs [CBSE 1988]

(a)

3|

3

CH

COOHCHCH (b) 3222 CHCHCHCHCH (c)

2

3

|

3

NH

CHCHCH (d)

2

3

|

23

NH

CHCHCHCH

145. Hydrogenation of the adjoining compound in the presence of poisoned palladium catalyst gives [IIT Screening 2001]

Me

Me

Me

H

H

H

ISOMERISM

EDUDIGM Be sincere, not serious

(a) An optically active compound (b) An optically inactive compound

(c) A racemic mixture (d) A diastereomeric mixture

146. Which of the following contains asymmetric centre [CPMT 1996]

(a) 2-butene (b) 2, 2-dimethylpropane (c) 2-hexyne (d) Lactic acid

147. Which of the following is expected to be optically active [JIPMER 1997]

(a) CCH 43)( (b) 73352 )( HCCHCHHC (c) 3252 )( CHCHHC (d) 33 CHCHCHCH

148. Which compound does not show geometrical isomerism [RPMT 1997]

(a) 2-butene (b) 2-pentene (c) 2, 3-dibromo-2-butene (d) 2-methyl propene

149. The optically active tartaric acid is named as D – (+) – tartaric acid because it has a positive [IIT 1999]

(a) Optical rotation and is derived from D-glucose

(b) pH in organic solvent

(c) Optical rotation and is derived from D – (+) – glyceraldehyde

(d) Optical rotation only when substituted by deuterium

150. Which one of the following is an optically active compound [CBSE 1988; DPMT 1983]

(a) n-propanol (b) 2-chlorobutane (c) n-butanol (d) 4-hydroxyheptane

151. Lactic acid in which a methyl group, a hydroxyl group, a carboxylic acid group and a hydrogen atom are attached to a

central carbon atom, shown optical isomerism due to the molecular geometry at the [Pb. PMT 2000]

(a) Central carbon atom (b) Carbon atom of the methyl group

(c) Carbon atom of the carboxylic acid group (d) Oxygen of the hydroxyl groups

152. . How many structures of F is possible (Geometrical) [IIT Screening 2003]

(a) 2 (b) 5 (c) 6 (d) 3

153. Separating of d- and l- enantiomorphs from a racemic mixture is called [CBSE 1988; DPMT 1983; KCET 2002]

(a) Resolution (b) Dehydration (c) Rotation (d) Dehydrohalogenation

154. Meso-tartaric acid is [BHU 2001]

(a) Optically inactive (b) Optically active because of molecular symmetry

(c) Optically inactive due to external compensation (d) Optically active because of asymmetric carbon atom

155. 1, 2-dichloroethene shows [RPET 1999]

(a) Geometrical isomerism (b) Optical isomerism (c) Ring-chain isomerism (d) Resonance

156. Which of the following does not show geometrical isomerism [AIEEE 2002]

(a) 1, 2-dichloro-1-pentene (b) 1, 3-dichloro-2-pentene (c) 1, 1-dichloro-1-pentene (d) 1, 4-dichloro-2-pentene

157. Methyl acetate and propionic acid are [RPMT 2002]

(a) Functional isomer (b) Structural isomer (c) Stereoisomer (d) Geometrical isomer

158. Lactic acid shows which type of isomerism [CPMT 1987; MP PMT 1987]

(a) Geometrical isomerism (b) Tautomerism (c) Optical isomerism (d) Metamerism

159. On bromination, propionic acid yields two isomeric 2-bromopropionic acids. This pair is an important example of[BHU 2000]

(a) Chain isomers (b) Optical isomers (c) Cis-trans isomers (d) Position isomers

160. The maximum number of stereoisomers possible for 2-hydroxy-2-methyl butanoic acid is [Roorkee 1992]

(a) 1 (b) 2 (c) 3 (d) 4

161. d-tartaric acid and l-tartaric acid are [MH CET 1999]

(a) Enantiomers (b) Tautomers (c) Diastereoisomers (d) Structural isomers

162. Which of the following compounds does not contain a chiral carbon

(a) 1-chlorobutane (b) 2-chlorobutane (c) 3-chloro-3-methylhexane (d) 2-butanol

163. Which of the following compounds may not exist as enantiomers [CPMT 1987]

(a) HCOOHCHCH 23 )( (b) OHCHCHCHCHCH 2323 )( (c) 3256 CHCHHC (d) 356 CHClCHHC

164. Which compound is optically active [DCE 1999]

CH3

H3C OH

ISOMERISM

EDUDIGM Be sincere, not serious

(a) 4-chloro-1-hydroxy butane (b) 3o-butyl alcohol

(c) Secondary butyl amine (d) n-butyl alcohol

165. Which compound shows cis-trans isomerism [CPMT 2002]

(a) 1-butene (b) 2-propene (c) 2-butene (d) Benzene

166. Which compound is chiral [RPMT 2002]

(a) Butane (b) 1-chloro-2-methyl butane (c) 2-methyl butane (d) 2-methyl propane

167. Which of the following compounds exhibit optical isomerism [BHU 1983; AFMC 1990; CPMT 1993; MP PMT 1999, 2000]

(a) COOHCHCH 23 (b) CHOHCOOHCH 3 (c) OHCHCHCH 223 (d) 33CHOHCHCH

168. The number of geometrical isomers in case of a compound with the structure 523 HCCHCHCHCHCH is[NCERT 1980]

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

169. Geometrical isomerism is shown by [IIT 1983; CPMT 1990, 94; CBSE 1992; MP PET 1997; AMU (Engg.) 1999]

(a) 2-butene (b) 2-butyne (c) 2-butanol (d) Butanal

170. An enantiomerically pure acid is treated with racemic mixture of an alcohol having one chiral carbon. The ester formed

will be

[IIT Screening 2003]

(a) Optically active mixture (b) Pure enantiomer (c) Meso compound (d) Racemic mixture

171. Which of the following compounds will show geometrical isomerism [IIT 1998]

(a) 2-butene (b) Propene (c) 1-phenylpropene (d) 2-methyl-2-butene

172. Which pair show cis-trans isomerism [RPET 1999]

(a) Maleic-fumaric acid (b) Lactic-tartaric acid (c) Malonic-succinic acid (d) Crotonic-acrylic acid

173. The isomeric cis-2-butene and trans-2-butene can be distinguished on the basis of [NTSE 1991]

(a) Their physical state (b) Their reduction products

(c) The products they give on ozonolysis (d) The products they give on addition to bromine

174. Number of optical isomers of lactic acid are

(a) 1 (b) 2 (c) 3 (d) 4

175. Which of the following compounds is not chiral [CBSE 1998]

(a) ClCHCHDCH 222 (b) CHDClCHCH 23 (c) ClCHCHDCHCH 223 (d) DCHClCHCH 22

176. What is the possible number of optical isomers for a compound containing 2-dissimilar asymmetric carbon atom

[CPMT 1999; UPSEAT 1999, 2000, 02]

(a) 2 (b) 4 (c) 6 (d) 8

177. Which of the following compounds which is an optically active compound [UPSEAT 1999]

(a) 1-butanol (b) 2-butanol (c) 3-butanol (d) 4-heptanol

178. Optically active compound is [UPSEAT 2002]

(a) 3-chloropentane (b) 2-chlorobutane (c) 2-chloropropane (d) None of these

179. The most stable conformation of n-butane is [CBSE 1997]

(a) Skew boat (b) Eclipsed (c) Gauche (d) Staggered

180. Isomerism due to rotation round single bond of carbon-carbon is [UPSEAT 2003]

(a) Conformation (b) Enantiomerism (c) Diastereo isomerism (d) Position isomerism

181. Which statement is true for cyclohexane [MP PET 1996]

(a) It has two possible isomers (b) It has three conformations

(c) Boat conformation is most stable (d) Chair and boat conformations differ in energy by 44

kJ/mol

182. What are the type of isomers in following pairs

(a) Conformers (b) Position (c) Optical (d) Geometrical

H H

H CH3

(I)

CH3 H

H H

H

CH3 H

(II

)

CH3

and

ISOMERISM

EDUDIGM Be sincere, not serious

183. Which type of conformation is shown by I and II

(a) I is eclipsed, II is staggered (b) II is eclipsed, I is staggered

(c) Both are eclipsed (d) Both are staggered

184. The dihedral angle between the hydrogen atoms of the two methyl groups in staggered conformation of ethane is

[CBSE 2000; IIT 2004]

(a) o120 (b) o60 (c) o180 (d) o90

185. Which of the following molecule can exhibit conformational isomers

(a) 62HC (b) 22OH (c) 22 NHNH (d) All of the above

186. Least hindered rotation about carbon-carbon bond is observed in [RPMT 2000]

(a) Ethane (b) Ethylene (c) Ethyne (d) Hexachloroethane

187. In ethane and cyclohexane which one of the following pairs of conformations are more stable

(a) Eclipsed and chair conformations (b) Staggered and chair conformations

(c) Staggered and boat conformations (d) Eclipsed and boat conformations

188. The isomers which can be converted into another forms by rotation of the molecules around single bond are [AIIMS 1997]

(a) Geometrical isomers (b) Conformers (c) Enantiomers (d) Diastereomers

189. Which one of the following represents eclipsed form of ethane

(a) (b) (c) (d) None of these

190. Which are the staggered forms of ethane

(a) (1) and (4) (b) (3) and (4) (c) (2) and (4) (d) (1) and (3)

191. Example of chlorinolysis is [CPMT 1992]

(a) 242222 ClHCCHCH

Cl (b) HClCOClOHCCl 2224

(c) OHNaClHCOONaNaOHCHCl 23 234 (d) HClClCCClHCCl

8624832

192. What is the order of reactivity of the alkenes )I()( 223 CHCCH , 23 CHCHCH (II) and 22 CHCH (III) when subjected to

acid-catalysed hydration

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

193. The most unlikely representation of resonance structures of p-nitrophenoxide ion is

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

194. The compounds

3

3

CHH

CC

HCH

and

HH

CC

CHCH 33

can be distinguished by their

(a) Chlorinated products (b) Products formed by addition of bromine

H H

H

H

H H

(I)

H H

H

H

H

H

(II)

(2)

C H H

H C

H H

H

H

H

(1)

H H H

H

H

H

(4)

H

H H

H (3) C

H H

H

C H

H

H

O

N + O

–

O –

O O

N +

O –

O N +

O

O –

H

H H

H H

H

H

H H H H

H H H

H

H H

H

O O

N +

O –

–

ISOMERISM

EDUDIGM Be sincere, not serious

(c) Reaction with NiH /2 (d) None of these

195. During elimination reactions, the hybrid state of carbon atoms involved in change shows

(a) 3sp to 2sp nature (b) 2sp to sp nature

(c) No change in hybridised state (d) Either of the above

196. An unknown compound A has a molecular formula 64 HC . When A is treated with an excess of 2Br a new substance B with

formula 464 BrHC is formed. A forms a white ppt. with ammoniacal silver nitrate solution. A may be [MP PMT 1998]

(a) But-1-yne (b) But-2-yne (c) But-1-ene (d) But-2-ene