This comprehensive set of MCQs on Organic Chemistry is designed to cover all essential topics required for success in the Medical and Dental College Admission Test (MDCAT). Focused on key subjects such as Hydrocarbons, Functional Groups, Reaction Mechanisms, and Stereochemistry, these MCQs are crafted to help aspiring medical and dental students build a solid foundation in organic chemistry and its significance in health sciences.
Who should practice Organic Chemistry MCQs?
- Students preparing for the MDCAT who wish to deepen their understanding of organic compounds and their reactions, which are critical for success in medical and dental fields.
- Individuals seeking to enhance their knowledge of reaction mechanisms and functional group transformations, essential for various biological and pharmacological applications.
- University students targeting high-yield topics like spectroscopy, organic synthesis, and the biochemical roles of organic molecules.
- Anyone aiming to strengthen their foundational understanding of organic chemistry and its implications for health and disease.
- Candidates focused on developing critical thinking and analytical skills related to organic reactions and their relevance to real-world applications.
1. Organic compounds are primarily classified based on:
A) Molecular weight
B) Functional groups
C) Color
D) Density
View AnswerB
2. Which of the following is a saturated hydrocarbon?
A) Ethylene
B) Propylene
C) Butane
D) Acetylene
View AnswerC
3. An isomer that differs in the arrangement of atoms in space is called:
A) Structural isomer
B) Geometric isomer
C) Conformational isomer
D) Optical isomer
View AnswerB
4. The presence of a double bond in a hydrocarbon makes it:
A) Saturated
B) Unsaturated
C) Aromatic
D) Aliphatic
View AnswerB
5. Which of the following compounds is an example of a ketone?
A) Butanal
B) Butanone
C) Propanoic acid
D) Ethanol
View AnswerB
6. The functional group characteristic of alcohols is:
A) -OH
B) -COOH
C) -CHO
D) -C=O
View AnswerA
7. Which of the following is a type of structural isomerism?
A) Cis-trans isomerism
B) Enantiomerism
C) Conformational isomerism
D) Chain isomerism
View AnswerD
8. Which compound has the molecular formula C₆H₁₂O?
A) Glucose
B) Fructose
C) Hexanal
D) Hexan-2-one
View AnswerA
9. The simplest form of an alkane is:
A) Ethane
B) Methane
C) Propane
D) Butane
View AnswerB
10. Which of the following is an example of a carboxylic acid?
A) Ethanol
B) Acetic acid
C) Propan-1-ol
D) Benzene
View AnswerB
11. Geometric isomers arise from the:
A) Different connectivity of atoms
B) Restricted rotation around a double bond
C) Presence of chiral centers
D) Same molecular formula
View AnswerB
12. What type of isomerism does 2-butene exhibit?
A) Chain isomerism
B) Position isomerism
C) Geometric isomerism
D) Functional group isomerism
View AnswerC
13. Which of the following compounds can exhibit optical isomerism?
A) Propane
B) 2-butanol
C) Butene
D) Ethyne
View AnswerB
14. The molecular formula C₈H₁₈ represents:
A) An alkene
B) An alkane
C) An alkyne
D) An aromatic compound
View AnswerB
15. The primary functional group in aldehydes is:
A) -OH
B) -CHO
C) -C=O
D) -COOH
View AnswerB
16. Which of the following is an aromatic compound?
A) Cyclohexane
B) Benzene
C) Ethylene
D) Butyne
View AnswerB
17. Which type of isomerism is shown by glucose and fructose?
A) Geometric isomerism
B) Structural isomerism
C) Optical isomerism
D) Position isomerism
View AnswerB
18. The presence of a triple bond in a hydrocarbon makes it:
A) Saturated
B) Unsaturated
C) Aromatic
D) Aliphatic
View AnswerB
19. Which of the following is an example of a primary alcohol?
A) 1-butanol
B) 2-butanol
C) 1-pentanol
D) 2-pentanol
View AnswerA
20. Which of the following compounds is a secondary amine?
A) Methylamine
B) Dimethylamine
C) Ethylamine
D) Trimethylamine
View AnswerB
21. Which compound is an example of a thiol?
A) Ethanol
B) Methanethiol
C) Butanone
D) Benzyl alcohol
View AnswerB
22. The functional group -NH₂ is characteristic of:
A) Alcohols
B) Amines
C) Aldehydes
D) Ketones
View AnswerB
23. Which of the following has the highest boiling point?
A) Butane
B) Butanol
C) Butyric acid
D) Butyronitrile
View AnswerC
24. The process of converting unsaturated fats to saturated fats is called:
A) Saponification
B) Hydrogenation
C) Halogenation
D) Oxidation
View AnswerB
25. Which of the following is not a property of alkenes?
A) They are more reactive than alkanes.
B) They contain a carbon-carbon double bond.
C) They can undergo electrophilic addition reactions.
D) They have a higher boiling point than alkanes.
View AnswerD
26. The molecular formula C₅H₁₀ indicates that the compound is:
A) An alkane
B) An alkene
C) An alkyne
D) An aromatic compound
View AnswerB
27. The functional group of esters is characterized by:
A) -OH
B) -C=O
C) -COOR
D) -NH₂
View AnswerC
28. Which of the following compounds exhibits cis-trans isomerism?
A) Butyne
B) 2-butene
C) 2-pentanol
D) Methanol
View AnswerB
29. Which type of isomerism arises due to different connectivity of atoms?
A) Geometric isomerism
B) Functional group isomerism
C) Structural isomerism
D) Optical isomerism
View AnswerC
30. The main type of isomerism exhibited by butane and isobutane is:
A) Geometric isomerism
B) Chain isomerism
C) Position isomerism
D) Functional group isomerism
View AnswerB
31. Which of the following compounds has a chiral center?
A) 2-butanol
B) Ethanol
C) Propanol
D) 1-butanol
View AnswerA
32. The term “chiral” refers to a molecule that:
A) Has no optical activity
B) Is superimposable on its mirror image
C) Is not superimposable on its mirror image
D) Has identical functional groups
View AnswerC
33. Which compound can exhibit tautomerism?
A) Ethanol
B) Acetaldehyde
C) 2-butanol
D) 1-butyne
View AnswerB
34. The compound with the formula C₃H₈ is known as:
A) Propylene
B) Propane
C) Acetylene
D) Butane
View AnswerB
35. The main characteristic of aromatic compounds is:
A) They have a single bond between carbon atoms.
B) They can exhibit geometric isomerism.
C) They contain a benzene ring.
D) They are saturated hydrocarbons.
View AnswerC
36. Which of the following compounds is a primary amine?
A) Ethanolamine
B) Dimethylamine
C) Ethylamine
D) Trimethylamine
View AnswerC
37. Which of the following is a characteristic of aliphatic compounds?
A) They contain a benzene ring.
B) They are cyclic in nature.
C) They can be straight-chain or branched.
D) They do not contain carbon.
View AnswerC
38. Which of the following is a characteristic feature of structural isomers?
A) Same molecular formula
B) Same physical properties
C) Different functional groups
D) Same connectivity of atoms
View AnswerA
39. Which of the following pairs of compounds are functional group isomers?
A) Ethanol and dimethyl ether
B) Propane and propene
C) Butane and isobutane
D) 1-butanol and 2-butanol
View AnswerA
40. The presence of a hydroxyl group (-OH) classifies a compound as:
A) Alcohol
B) Ether
C) Aldehyde
D) Ketone
View AnswerA
41. Which of the following is a characteristic of cyclic compounds?
A) They are always saturated.
B) They have a closed ring structure.
C) They contain only single bonds.
D) They cannot exhibit isomerism.
View AnswerB
42. Which of the following compounds exhibits resonance?
A) Benzene
B) Ethylene
C) Propane
D) Cyclohexane
View AnswerA
43. The term “functional group” refers to:
A) The hydrocarbon chain of a compound
B) A specific group of atoms that determines the compound’s properties
C) The molecular weight of a compound
D) The number of carbon atoms in a compound
View AnswerB
44. Which of the following compounds is a diene?
A) Butadiene
B) Ethylene
C) Propylene
D) Isobutane
View AnswerA
45. The molecular formula C₄H₈ can represent:
A) Butane only
B) 1-butene only
C) Both butane and 1-butene
D) Neither butane nor 1-butene
View AnswerC
46. Which of the following is a characteristic of alkenes?
A) They can undergo addition reactions.
B) They are completely saturated.
C) They have only single bonds.
D) They have a linear structure.
View AnswerA
47. Which type of structural isomerism arises from the difference in the position of the functional group?
A) Chain isomerism
B) Geometric isomerism
C) Position isomerism
D) Functional group isomerism
View AnswerC
48. The presence of a carbon-carbon triple bond in a compound identifies it as an:
A) Alkane
B) Alkene
C) Alkyne
D) Aromatic compound
View AnswerC
49. Which of the following compounds can exhibit geometric isomerism?
A) 1-butene
B) 2-butene
C) Propane
D) 1-pentyne
View AnswerB
50. The chemical structure of butyric acid features:
A) An ester group
B) A carboxyl group
C) An alcohol group
D) A ketone group
View AnswerB
51. The term “conformational isomer” refers to:
A) Isomers that differ in the arrangement of atoms in space due to rotation around single bonds
B) Isomers that differ in the connectivity of atoms
C) Isomers that have the same molecular formula but different functional groups
D) Isomers that cannot be converted into each other
View AnswerA
52. Which of the following compounds has the same molecular formula but different structural formulas?
A) Ethanol and dimethyl ether
B) Propane and propene
C) Butane and isobutane
D) Both A and C
View AnswerD
53. Which functional group is present in aldehydes?
A) -OH
B) -CHO
C) -C=O
D) -NH₂
View AnswerB
54. The main characteristic of aromatic hydrocarbons is:
A) They have a carbon-carbon double bond.
B) They are cyclic and planar.
C) They are linear in structure.
D) They do not contain carbon.
View AnswerB
55. Which of the following compounds exhibits optical isomerism?
A) 2-butanol
B) 2-pentene
C) Ethylene
D) Propane
View AnswerA
56. The simplest alcohol is:
A) Ethanol
B) Methanol
C) Propanol
D) Butanol
View AnswerB
57. Which of the following compounds is an ether?
A) Methanol
B) Ethyl acetate
C) Dimethyl ether
D) Butanoic acid
View AnswerC
58. Which type of isomerism is shown by glucose and mannose?
A) Geometric isomerism
B) Structural isomerism
C) Optical isomerism
D) Position isomerism
View AnswerC
59. The compound with the formula C₄H₁₀ can be classified as:
A) An alkane
B) An alkene
C) An alkyne
D) An aromatic compound
View AnswerA
60. Which of the following is a feature of tertiary alcohols?
A) They have one hydroxyl group.
B) They do not exhibit oxidation.
C) They have a carbon atom bonded to three alkyl groups.
D) They cannot undergo dehydration.
View AnswerC
61. Which of the following compounds is a saturated fatty acid?
A) Oleic acid
B) Stearic acid
C) Linoleic acid
D) Palmitoleic acid
View AnswerB
62. Which of the following compounds is a conjugated diene?
A) Butadiene
B) 1,3-hexadiene
C) 1,4-hexadiene
D) 2,4-hexadiene
View AnswerB
63. The presence of a carbonyl group in a compound classifies it as:
A) Alcohol
B) Aldehyde
C) Ketone
D) Both B and C
View AnswerD
64. The compound with the formula C₁₁H₂₂ is:
A) Nonane
B) Undecane
C) Dodecane
D) Decane
View AnswerB
65. Which of the following is true for isomerism?
A) Isomers have the same molecular formula.
B) Isomers have different properties.
C) Isomers can be structural or stereoisomers.
D) All of the above.
View AnswerD
66. Which of the following compounds contains a double bond?
A) Butane
B) Butene
C) Butyne
D) All of the above
View AnswerB
67. The process of breaking down a larger organic molecule into smaller ones is called:
A) Synthesis
B) Decomposition
C) Polymerization
D) Isomerization
View AnswerB
68. Which of the following is an example of a cyclic alkane?
A) Hexane
B) Cyclohexane
C) Butane
D) Propane
View AnswerB
69. Which functional group is characteristic of amides?
A) -COOH
B) -NH₂
C) -CONH₂
D) -C=O
View AnswerC
70. Which of the following is an example of a ketone?
A) Acetone
B) Ethanol
C) Propanoic acid
D) Methanol
View AnswerA
71. Which of the following is true for enantiomers?
A) They have the same physical properties.
B) They are non-superimposable mirror images.
C) They cannot rotate plane-polarized light.
D) They have identical boiling points.
View AnswerB
72. Which of the following compounds is a secondary alcohol?
A) Methanol
B) 2-propanol
C) 1-butanol
D) Ethanol
View AnswerB
73. The chemical structure of acetic acid features:
A) An alcohol group
B) A carboxyl group
C) A carbonyl group
D) An ester group
View AnswerB
74. Which of the following pairs are positional isomers?
A) Ethanol and methoxymethane
B) 1-butanol and 2-butanol
C) Butane and isobutane
D) Ethylene and acetylene
View AnswerB
75. The IUPAC name for the compound CH₃(CH₂)₃COOH is:
A) Propanoic acid
B) Butanoic acid
C) Pentanoic acid
D) Hexanoic acid
View AnswerB
76. Which of the following compounds is an alkyne?
A) Ethylene
B) Acetylene
C) Propylene
D) Benzene
View AnswerB
77. Which functional group is present in carboxylic acids?
A) -OH
B) -COOH
C) -C=O
D) -NH₂
View AnswerB
78. The simplest ketone is:
A) Acetone
B) Propan-1-one
C) Butan-2-one
D) Ethanol
View AnswerA
79. Which of the following is a characteristic of an aldehyde?
A) They cannot be oxidized.
B) They have a carbonyl group at the end of the carbon chain.
C) They cannot undergo reduction.
D) They are always saturated.
View AnswerB
80. Which of the following compounds can undergo dehydration to form an alkene?
A) Alcohols
B) Ethers
C) Ketones
D) Carboxylic acids
View AnswerA
81. Which type of isomerism occurs in compounds with the same molecular formula but different spatial arrangements?
A) Structural isomerism
B) Geometric isomerism
C) Optical isomerism
D) Both B and C
View AnswerD
82. The presence of a nitrogen atom in an organic compound classifies it as:
A) An alcohol
B) An amine
C) An aldehyde
D) A ketone
View AnswerB
83. The molecular formula C₇H₁₄ represents:
A) A saturated hydrocarbon
B) An unsaturated hydrocarbon
C) An aromatic compound
D) A cyclic compound
View AnswerA
84. Which of the following compounds is a primary amine?
A) Ethylamine
B) Aniline
C) Dimethylamine
D) Trimethylamine
View AnswerA
85. Which of the following compounds contains an ester functional group?
A) Ethanol
B) Ethyl acetate
C) Butanoic acid
D) Acetic acid
View AnswerB
86. Which of the following is true about stereoisomers?
A) They have different connectivity of atoms.
B) They have the same molecular formula but different arrangements in space.
C) They have different boiling points.
D) They are always structural isomers.
View AnswerB
87. Which of the following compounds is an example of a cyclic alkene?
A) Cyclopentene
B) Cyclohexane
C) Cyclohexanol
D) Cyclobutane
View AnswerA
88. The compound with the formula C₈H₁₈ is:
A) Octane
B) Nonane
C) Decane
D) Hexane
View AnswerA
89. Which of the following compounds can be classified as a heterocyclic compound?
A) Benzene
B) Pyridine
C) Cyclohexane
D) Cyclobutane
View AnswerB
90. The functional group of a phenol is:
A) -OH
B) -COOH
C) -C=O
D) -NH₂
View AnswerA
91. Which of the following is a property of alcohols?
A) They have high boiling points.
B) They are generally nonpolar.
C) They do not participate in hydrogen bonding.
D) They are weak acids.
View AnswerA
92. Which of the following compounds is an aromatic compound?
A) Cyclopropane
B) Toluene
C) Propane
D) Butane
View AnswerB
93. Which of the following compounds can form hydrogen bonds?
A) Ethylene
B) Ethanol
C) Benzene
D) Cyclohexane
View AnswerB
94. Which of the following compounds is a tertiary amine?
A) Methylamine
B) Dimethylamine
C) Trimethylamine
D) Ethylamine
View AnswerC
95. Which of the following is a characteristic of a ketone?
A) They cannot be oxidized.
B) They have a carbonyl group located at the end of the carbon chain.
C) They have a carbonyl group located within the carbon chain.
D) They are always saturated.
View AnswerC
96. Which of the following compounds is a cyclic compound?
A) Butane
B) Ethene
C) Cyclobutane
D) Propylene
View AnswerC
97. The simplest alkene is:
A) Propylene
B) Ethylene
C) Butylene
D) Isobutylene
View AnswerB
98. Which of the following compounds can act as a Lewis acid?
A) Water
B) Boron trifluoride
C) Ethylene
D) Ammonia
View AnswerB
99. The chemical formula for glucose is:
A) C₆H₁₂O₆
B) C₆H₁₁O₆
C) C₇H₁₂O₆
D) C₇H₁₁O₇
View AnswerA
100. The term “aromatic” refers to:
A) Compounds with a pleasant smell.
B) Compounds that are cyclic and have delocalized π-electrons.
C) Compounds that do not contain any double bonds.
D) Compounds with high molecular weight.
View AnswerB