MCQs on Amines – CBSE Class 12 Chemistry
MCQs on Amines – CBSE Class 12 Chemistry
Organic Chemistry | NCERT-Based | MCQs with Answers & Explanations
The following 50 Multiple Choice Questions (MCQs) are strictly prepared according to the NCERT syllabus for CBSE Class 12 Chemistry.
They are arranged section-wise to cover classification, nomenclature, preparation, physical properties, chemical reactions, basic strength, and applications of amines, with clear, concept-oriented explanations ideal for CBSE board exam preparation.
Section A: Classification & Nomenclature of Amines
Q1. Amines are derivatives of:
A. Ammonia
B. Alcohol
C. Aldehyde
D. Carboxylic acid
Answer: A
Explanation:
Amines are formed by replacing one or more hydrogen atoms of ammonia (NH₃) with alkyl or aryl groups.
Q2. Which of the following is a primary amine?
A. (CH₃)₃N
B. CH₃NH₂
C. (CH₃)₂NH
D. C₆H₅NHCH₃
Answer: B
Explanation:
In CH₃NH₂, nitrogen is attached to one alkyl group, making it a primary amine.
Q3. Which compound is a secondary amine?
A. CH₃NH₂
B. (CH₃)₂NH
C. (CH₃)₃N
D. C₆H₅NH₂
Answer: B
Explanation:
Secondary amines have two alkyl/aryl groups attached to nitrogen.
Q4. The IUPAC name of CH₃CH₂NH₂ is:
A. Ethylamine
B. Ethanamine
C. Methylamine
D. Aminoethane
Answer: B
Explanation:
According to IUPAC rules, the name is ethanamine.
Q5. Which of the following is an aromatic amine?
A. CH₃NH₂
B. (CH₃)₂NH
C. C₆H₅NH₂
D. CH₃CH₂NH₂
Answer: C
Explanation:
Aniline (C₆H₅NH₂) is an aromatic amine because –NH₂ is attached to a benzene ring.
Section B: Methods of Preparation of Amines
Q6. Amines can be prepared from nitro compounds by:
A. Oxidation
B. Reduction
C. Hydrolysis
D. Dehydration
Answer: B
Explanation:
Nitro compounds are reduced (using Sn/HCl, Fe/HCl, or H₂/Ni) to form amines.
Q7. Which reaction converts amides to amines with one carbon less?
A. Hofmann bromamide reaction
B. Wurtz reaction
C. Sandmeyer reaction
D. Gabriel synthesis
Answer: A
Explanation:
Hofmann bromamide reaction forms amines with one carbon less than the parent amide.
Q8. Gabriel phthalimide synthesis is used to prepare:
A. Secondary amines
B. Tertiary amines
C. Primary amines only
D. Aromatic amines only
Answer: C
Explanation:
Gabriel synthesis yields only primary aliphatic amines.
Q9. Which reagent converts nitriles into amines?
A. NaBH₄
B. LiAlH₄
C. KMnO₄
D. H₂SO₄
Answer: B
Explanation:
LiAlH₄ reduces nitriles to primary amines.
Q10. Reduction of nitrobenzene produces:
A. Aniline
B. Benzylamine
C. Phenylamine oxide
D. Benzamide
Answer: A
Explanation:
Nitrobenzene reduces to aniline, an aromatic amine.
Section C: Physical Properties of Amines
Q11. Amines have lower boiling points than alcohols of comparable molar mass because:
A. They are non-polar
B. They have weaker hydrogen bonding
C. They are volatile
D. They lack lone pairs
Answer: B
Explanation:
Hydrogen bonding in amines is weaker than in alcohols.
Q12. Which amine has the highest boiling point?
A. Primary amine
B. Secondary amine
C. Tertiary amine
D. Aromatic amine
Answer: A
Explanation:
Primary amines form the maximum number of hydrogen bonds.
Q13. Lower aliphatic amines are soluble in water because:
A. They are ionic
B. They are acidic
C. They form hydrogen bonds with water
D. They react with water
Answer: C
Explanation:
Amines form hydrogen bonds with water molecules.
Q14. Which amine has a fishy odor?
A. Aniline
B. Methylamine
C. Ammonium chloride
D. Acetamide
Answer: B
Explanation:
Lower aliphatic amines have a fishy smell.
Q15. Which compound is least soluble in water?
A. Methylamine
B. Ethylamine
C. Aniline
D. Dimethylamine
Answer: C
Explanation:
Aromatic amines like aniline are less soluble due to large hydrophobic benzene ring.
Section D: Basic Nature of Amines
Q16. Amines act as bases because:
A. They release H⁺ ions
B. They donate OH⁻ ions
C. They have a lone pair on nitrogen
D. They contain hydrogen
Answer: C
Explanation:
The lone pair of electrons on nitrogen makes amines basic.
Q17. Which aliphatic amine is the strongest base in aqueous solution?
A. Primary
B. Secondary
C. Tertiary
D. Equal strength
Answer: B
Explanation:
Secondary amines show maximum basicity due to +I effect and solvation.
Q18. Aniline is less basic than methylamine because:
A. It has higher molar mass
B. Lone pair is delocalized by resonance
C. It is aromatic
D. It is insoluble
Answer: B
Explanation:
In aniline, the lone pair participates in resonance with benzene ring, reducing availability.
Q19. The basic strength of amines in gas phase depends mainly on:
A. Solvation
B. Hydrogen bonding
C. +I effect
D. Steric hindrance
Answer: C
Explanation:
In gas phase, electron-donating inductive effect dominates.
Q20. Which amine is the weakest base?
A. Methylamine
B. Dimethylamine
C. Trimethylamine
D. Aniline
Answer: D
Explanation:
Resonance decreases basicity of aniline.
Section E: Chemical Reactions of Amines
Q21. Primary amines react with nitrous acid to form:
A. Alcohols only
B. Diazonium salts (aromatic)
C. Nitro compounds
D. Amides
Answer: B
Explanation:
Aromatic primary amines form diazonium salts with nitrous acid.
Q22. Which amine gives carbylamine test?
A. Primary amines only
B. Secondary amines
C. Tertiary amines
D. All amines
Answer: A
Explanation:
Only primary amines give carbylamine (isocyanide) test.
Q23. The reagent used in carbylamine test is:
A. CHCl₃ and KOH
B. NaOH only
C. HCl
D. KMnO₄
Answer: A
Explanation:
Primary amines react with chloroform and alcoholic KOH.
Q24. Which compound gives offensive smell in carbylamine test?
A. Alcohol
B. Amide
C. Isocyanide
D. Ammonia
Answer: C
Explanation:
Formation of isocyanides produces foul smell.
Q25. Aniline reacts with bromine water to form:
A. Bromobenzene
B. o-Bromoaniline
C. p-Bromoaniline
D. 2,4,6-Tribromoaniline
Answer: D
Explanation:
Strong activating –NH₂ group causes polybromination.
Section F: Diazonium Salts & Their Reactions
Q26. Diazonium salts are prepared at temperature:
A. 0–5°C
B. 25°C
C. 50°C
D. 100°C
Answer: A
Explanation:
Low temperature prevents decomposition of diazonium salts.
Q27. Which compound is most stable diazonium salt?
A. Methyl diazonium chloride
B. Ethyl diazonium chloride
C. Benzene diazonium chloride
D. Propyl diazonium chloride
Answer: C
Explanation:
Aromatic diazonium salts are relatively stable.
Q28. Sandmeyer reaction is used to prepare:
A. Phenols
B. Alkyl halides
C. Aryl halides
D. Amines
Answer: C
Explanation:
Sandmeyer reaction converts diazonium salts into aryl halides.
Q29. Benzene diazonium chloride reacts with water to give:
A. Benzene
B. Phenol
C. Chlorobenzene
D. Nitrobenzene
Answer: B
Explanation:
Hydrolysis of diazonium salt yields phenol.
Q30. Coupling reaction of diazonium salts produces:
A. Alcohols
B. Ketones
C. Azo dyes
D. Esters
Answer: C
Explanation:
Azo coupling forms colored azo dyes.
Section G: NCERT-Based Mixed MCQs
Q31. Which amine is used as a dye intermediate?
A. Methylamine
B. Aniline
C. Dimethylamine
D. Trimethylamine
Answer: B
Explanation:
Aniline is widely used in dye manufacturing.
Q32. Which compound does not give carbylamine test?
A. Ethylamine
B. Aniline
C. Dimethylamine
D. Methylamine
Answer: C
Explanation:
Secondary amines do not give carbylamine test.
Q33. Which amine reacts with Hinsberg reagent to give insoluble sulphonamide?
A. Primary amine
B. Secondary amine
C. Tertiary amine
D. Ammonium salt
Answer: B
Explanation:
Secondary amines form insoluble sulphonamides.
Q34. Which test distinguishes primary, secondary and tertiary amines?
A. Lucas test
B. Victor Meyer test
C. Hinsberg test
D. Tollens’ test
Answer: C
Explanation:
Hinsberg test differentiates all three types of amines.
Q35. Which compound is least basic in aqueous solution?
A. CH₃NH₂
B. (CH₃)₂NH
C. (CH₃)₃N
D. C₆H₅NH₂
Answer: D
Explanation:
Aniline is least basic due to resonance effect.
Q36. Which amine gives yellow oily liquid in nitrous acid test?
A. Primary aliphatic amine
B. Secondary amine
C. Primary aromatic amine
D. Tertiary amine
Answer: B
Explanation:
Secondary amines form N-nitrosoamines, yellow oily liquids.
Q37. Which compound is formed when tertiary amines react with nitrous acid?
A. Diazonium salt
B. Alcohol
C. Nitrite salt
D. No reaction
Answer: D
Explanation:
Tertiary amines do not react with nitrous acid.
Q38. Which amine is used in rubber industry?
A. Aniline
B. Ethylamine
C. Methylamine
D. Ammonia
Answer: A
Explanation:
Aniline derivatives are used as rubber processing chemicals.
Q39. Which compound reacts fastest in diazotisation?
A. Aniline
B. Benzylamine
C. Methylamine
D. Ethylamine
Answer: A
Explanation:
Aromatic primary amines readily undergo diazotisation.
Q40. Which amine forms stable salts with acids?
A. Aliphatic amines
B. Aromatic amines
C. Both A and B
D. None
Answer: C
Explanation:
All amines form ammonium salts with acids.
Q41. Which amine has maximum +I effect?
A. Methylamine
B. Ethylamine
C. Dimethylamine
D. Trimethylamine
Answer: D
Explanation:
Three alkyl groups exert strongest electron-donating effect.
Q42. Which compound is used as local anesthetic?
A. Aniline
B. Procaine
C. Ammonia
D. Urea
Answer: B
Explanation:
Procaine is an amine-based local anesthetic.
Q43. Which amine reacts with benzene sulphonyl chloride to give soluble product?
A. Primary amine
B. Secondary amine
C. Tertiary amine
D. Amide
Answer: A
Explanation:
Primary amines form soluble sulphonamides in alkali.
Q44. Which compound has highest basicity in gas phase?
A. CH₃NH₂
B. (CH₃)₂NH
C. (CH₃)₃N
D. Aniline
Answer: C
Explanation:
In gas phase, +I effect dominates, making tertiary amine strongest base.
Q45. Which amine gives purple color with nitrous acid?
A. Primary aliphatic
B. Primary aromatic
C. Secondary
D. Tertiary
Answer: B
Explanation:
Primary aromatic amines form diazonium salts.
Q46. Which compound is used in the manufacture of azo dyes?
A. Benzene
B. Aniline
C. Phenol
D. Toluene
Answer: B
Explanation:
Aniline forms diazonium salts, precursors of azo dyes.
Q47. Which amine does not form hydrogen bonding among itself?
A. Primary amine
B. Secondary amine
C. Tertiary amine
D. Aromatic amine
Answer: C
Explanation:
Tertiary amines lack N–H bond, so no self hydrogen bonding.
Q48. Which amine is most soluble in water?
A. Aniline
B. Trimethylamine
C. Ethylamine
D. Benzylamine
Answer: C
Explanation:
Lower aliphatic amines are highly soluble in water.
Q49. Which reaction is used to introduce –NH₂ group into benzene ring?
A. Friedel–Crafts reaction
B. Nitration followed by reduction
C. Sandmeyer reaction
D. Wurtz reaction
Answer: B
Explanation:
Nitration followed by reduction yields aniline.
Q50. Amines are classified as primary, secondary or tertiary based on:
A. Molecular mass
B. Basicity
C. Number of carbon atoms attached to nitrogen
D. Solubility
Answer: C
Explanation:
Classification depends on number of alkyl/aryl groups attached to nitrogen.
✅ CBSE Exam Tip:
These MCQs are fully NCERT-aligned, concept-driven, and ideal for Class 12 board exams, revision practice, and objective assessments.