Stereochemistry MCQs [Organic Chemistry]

By: Prof. Dr. Fazal Rehman | Last updated: May 23, 2025

1. : Cis-2-Butene on reaction with bromine gives 2,3-dibromobutane which is
(A) Dextroisomer
(B) Meso-isomer
(C) Racemic mixture
(D) Laevoisomer

2. : How many stereoisomers are possible for CH3CH=CHCHCH(Br)CH3?
(A) 2-Geometrical isomers
(B) 2 Optical isomers
(C) 2-Geometrical and 1 optical isomer
(D) 2-Geometrical and 2 optical isomers

3. : Process of separating the racemic mixture into optically active isomers is famous as
(A) Racemization
(B) Resolution
(C) Walden inversion
(D) Epimerization

4. : Lactic acid is a molecule which shows
(A) Epimersim
(B) Optical isomerism
(C) Tautomerism
(D) Metamerism

5. : Different arrangements of groups in space which can be converted into one another by rotation around a single bond are known as _____.
(A) Configuration
(B) Conformations
(C) Enantiomers
(D) Metamers

6. : Stereoisomers not related to each other as object and mirror image are known as
(A) Enantiomers
(B) Diastereoisomers
(C) Antipodes
(D) Conformations

7. : Stereoisomers that can be interconverted by rotation about a single bond are known as _____.
(A) Conformers
(B) Chain isomers
(C) Functional isomers
(D) Tautomers

8. : Geometrical isomerism emerges due to which reason?
(A) High electron density between two substituted carbon
(B) Restricted rotation of substituents around double bond
(C) Both A & B
(D) None of these

9. : In E-Z nomenclature of stereoisomers, E will be assigned to
(A) If higher priority groups are on the same direction
(B) The geometrical isomers having higher priority groups on opposite direction
(C) Both A & B
(D) None of these

10. : In optical isomerism
(A) Laevorotatory are represented by (-) sign
(B) Dextrorotatory are represented by (+)
(C) Sometimes levo and sometimes dextro are represented by (-) sign
(D) Both A & B are wrong

11. : Geometrical isomerism can be exhibited by compounds having _____.
(A) –N=N–
(C) >C=C<
(D) All of these

12. : Which of the mentioned molecules can exhibit geometrical isomerism?
(A) CH3CH=C(CH3)2
(B) CH3CH=CHCH3
(C) (CH3)2C=CH2
(D) CH3CH=CH2

13. : How many optical isomers are possible for CH(OH)COOH CH—(Br) COOH?
(A) 2
(B) 4
(C) 3
(D) 8

14. : Which of the mentioned property has a higher value for trans-isomer as compared to cis-isomer?
(A) Melting point
(B) Dipole moment
(C) Density
(D) Boiling point

15. : Which configuration has lowest potential energy?
(A) Eclipsed
(B) Skew
(C) Staggered
(D) All have same energy

16. : D(+) glyceraldehyde has the absolute configuration
(A) R-
(B) S-
(C) E-
(D) Z-

17. : According to R, S system the correct order of priority of the following groups is
18. : The angle of rotation of plane polarized light in polarimeter relies on _____.
(A) Concentration of substance
(B) Nature of the substance
(C) Length of polarimeter tube
(D) All A, B, and C

19. : Which of the mentioned compounds shows tautomerism?
(A) Nitroethane
(B) Ethanol
(C) Ethoxyethane
(D) Chloroethane

20. : 2-Butanol is optically active because it contains
(A) An asymmetric carbon atom
(B) A plane of symmetry
(C) Centre of symmetry
(D) A hydroxyl group

21. : Which of the mentioned compound will be optically active?
(A) Lactic acid
(B) Meso-tartaric acid
(C) Acetic acid
(D) Succinic acid

22. : What is the possible number of optical isomers for a compound containing 2 dissimilar asymmetric carbon atoms?
(A) 2
(B) 6
(C) 4
(D) 8

23. : Which of the mentioned statements is wrong about enantiomers?
(A) Rotate plane of polarized light
(B) Have the same melting points
(C) Non superimposable mirror images
(D) Are superimposable mirror images

24. : Enantiomers have __________ characteristics?
(A) Have the same melting point
(B) Rotate ordinary light
(C) Are superimposable mirror images
(D) React with optically active molecules at the same rate

25. : It is possible to distinguish between optical isomers
(A) By polarimetry
(B) By mass spectrometry
(C) By IR spectroscopy
(D) Using chemical tests

26. : Plane polarized light is affected by
(A) Chiral molecules
(B) All polymers
(C) Identical molecules
(D) All biomolecules

27. : A molecule is said to be chiral if it __________.
(A) Contains plane of symmetry
(B) Contains center of symmetry
(C) Cannot be superimposed on its mirror image
(D) Can be superimposed on its mirror image

28. : An optically active compound _____.
(A) Must contain at least four carbons
(B) In solution always gives negative reading in polarimeter
(C) Must always contain an asymmetric carbon atom
(D) When in solution rotates the plane of polarized light

29. : Maleic acid and fumaric acid are_____.
(A) Geometrical isomers
(B) Enantiomers
(C) Homologous
(D) Diastereoisomers

30. : Which of the mentioned are structural isomers?
(A) Functional isomers
(B) Position isomers
(C) Chain isomers
(D) All A, B, and C

31. : n-Butane and 2-methylpropane are examples of ______.
(A) Functional isomers
(B) Position isomers
(C) Chain isomers
(D) Tautomers

32. : 1-Propanol and 2-propanol are examples of____.
(A) Position isomers
(B) Chain isomers
(C) Functional isomers
(D) Tautomers

33. : Acetone and diethyl ether are examples of
(A) Position isomers
(B) Chain isomers
(C) Functional isomers
(D) Tautomers

34. : Compounds HCN and HNC are _____.
(A) Conformers
(B) Metamers
(C) Functional isomers
(D) Tautomers

35. : Alkyl cyanide and alkyl isocyanides are _____.
(A) Tautomers
(B) Functional isomers
(C) Metamers
(D) Geometric isomers

36. : Several compounds corresponding to molecular formula C4H10 are _____.
(A) Functional isomers
(B) Chain isomers
(C) Tautomers
(D) Position isomers

37. : The device which is helpful and used to measure the optical activity is known as
(A) Polari scope
(B) Conductivity meter
(C) Potentiometer
(D) Photometer

38. : In Relative Configuration D & L are assigned __________.
(A) Number of chiral centers
(B) In relation to number of possible stereoisomers
(C) In relation to glyceraldehyde
(D) None of these

39. : Epimers are the stereoisomer of compound which
(A) Differ in configuration at one chiral center
(B) Differ in configuration at particular chiral center in a compound having more than one chiral center
(C) Differ in configuration at one chiral center only in cyclic compounds
(D) None of these

40. : In relative stability of conformational isomers of n-butane
(A) Anti-form lies at lowest energy
(B) Skew form lies at lower energy
(C) Both lies at lower energy but sometimes anti goes to higher energy
(D) None of these

41. : Which of the mentioned compounds show optical activity?
(A) Maleic acid
(B) Sucrose
(C) Aldehyde
(D) Oxalic acid

42. : Stereoisomers that are related like an object and its mirror image non-super imposable are known as
(A) Enantiomers
(B) Chain isomers
(C) Functional isomers
(D) Tautomers

43. : The configuration of a compound with reference to the arbitrarily assigned configuration is known as
(A) Absolute configuration
(B) Retention of configuration
(C) Relative configuration
(D) None of A, B, and C

44. : An equimolar mixture of a pair of enantiomers is known as
(A) Ideal mixture
(B) Racemate mixture
(C) Real mixture
(D) All A, B, and C

45. : Which of the mentioned is an element of symmetry?
(A) Centre of inversion
(B) Plane of symmetry
(C) Proper rotation
(D) All A, B, and C

46. : Which of the mentioned methods is helpful and used for resolution of racemic mixture?
(A) Physical method
(B) Biological method
(C) Chemical method
(D) All A, B, and C

47. : The functional isomers of ether are
(A) Hydrocarbons
(B) Ketones
(C) Aldehydes
(D) Alcohol

48. : The least cyclohexane is stable
(A) Chair
(B) Boat
(C) Half chair
Answer: (C) Half chair

49. : Which of the mentioned molecules can exhibit geometrical isomerism?
(A) CH3CH=CH₂
(B) CH3CH=CHCH3
(C) (CH3)2C=CH2
(D) CH3CH=C(CH3)2

50. : Stereoisomers not related to each other as object and mirror image are known as
(A) Enantiomers
(B) Antipodes
(C) Diastereoisomers
(D) Conformations

51. : Asymmetric center is characterized by which of the following?
(A) Having more than one functional groups attached to carbon
(B) Not having mirror image after a rotation of 180 degree
(C) Sp3 carbon with 4 different groups attached to carbon
(D) All of A, B, and C

52. : Which statement is true regarding Optical activity?
(A) Measure to evaluate degree of rotation of substituents in a chiral molecule
(B) The ability to rotate the plane of plane–polarized light
(C) To identify the direction of light (right or left) when it is targeted to chiral molecule
(D) None of these

53. : Chiral compounds are _______ forever
(A) Have acidic protons
(B) Optically active
(C) Have diastereomers
(D) Have enantiomers

54. : Examples of ______ are Diethyl ether and methyl propyl ether.
(A) Chain isomers
(B) Tautomers
(C) Stereoisomers
(D) Metamers

55. : Which is not a type of stereoisomer?
(A) Tautomers
(B) Optical isomers
(C) Conformational isomers
(D) Geometrical isomers

56. : Two structural isomers which differ in the relative positions of their atoms and are readily interconvertible are known as
(A) Functional isomers
(B) Chain isomers
(C) Tautomers
(D) Position isomers

57. : Isomers that have the same structural formula but differ in the arrangement of atoms in the three dimensional space are known as __.
(A) Stereoisomers
(B) Chain isomers
(C) Functional isomers
(D) Tautomers

58. : Benzene has
(A) Axis of symmetry
(B) Plane of symmetry
(C) Centre of symmetry
(D) All of A, B, and C

59. : Asymmetric carbon is that
(A) Which is attached with four different types of substituents
(B) Which has chiral center
(C) Which is attached with three different types of substituents
(D) Both a & b

60. : Enantiomers are the stereoisomers which
(A) Have at least one chiral center
(B) Not superimposable to their mirror images
(C) Have at least two chiral centers
(D) None of these

61. : What is the formula for calculation of Number of stereoisomers?
(A) (n) is number of substituents
(B) (n) is number carbon atoms
(C) (n) is number chiral centers
(D) None of these

62. : Stereochemistry studies the compound
(A) Spatial arrangement
(B) Rotation of substituents around single bond
(C) Distribution of substituents in carbon skeleton
(D) Optical activity

63. : The energy difference between staggered and eclipsed conformation of ethane is
(A) 25 kJ/mol
(B) 30 kJ/mol
(C) 12.5 kJ/mol
(D) 100 kJ/mol

64. : What is the total number of conformations of ethane?
(A) 3
(B) Infinite
(C) 7
(D) 5

65. : What is the energy difference between boat and chair conformation of cyclohexane?
(A) 44 kJ/mol
(B) 12.5 kJ/mol
(C) 100 kJ/mol
(D) 50 kJ/mol

66. : Various compounds corresponding molecular formula C4H10 are ______.
(A) Functional isomers
(B) Position isomers
(C) Tautomers
(D) Chain isomers

67. : Which of the mentioned methods helpful and used for the determination of configuration of geometrical isomers?
(A) Dipole moment
(B) Melting point
(C) Solubility
(D) All A, B, and C

68. : Anthracene is isomeric with which of the following?
(A) Physical method
(B) Naphthalene
(C) Benzene
(D) Phenanthrene