Amines are an essential class of organic compounds characterized by the presence of a nitrogen atom bonded to one or more alkyl or aryl groups. These compounds are derived from ammonia (NH3) by replacing one or more hydrogen atoms with organic substituents. Amines are classified based on the number of organic groups attached to the nitrogen atom: primary (one organic group), secondary (two organic groups), and tertiary (three organic groups).
Amines play a crucial role in organic chemistry and biochemistry due to their widespread occurrence and diverse functions. They are found in various natural products, pharmaceuticals, and industrial chemicals. Amines are known for their basicity, which arises from the lone pair of electrons on the nitrogen atom, allowing them to accept protons and form ammonium ions.
In the study of Class 12 Chemistry, understanding the properties, synthesis, and reactions of amines is vital. This chapter covers important aspects such as the nomenclature, structure, and preparation of amines, as well as their chemical behavior in different contexts. Mastering these concepts is essential for students preparing for competitive exams and further studies in chemistry.
To help students reinforce their understanding of amines, here are a set of multiple-choice questions (MCQs) covering various topics related to amines. These questions are designed to test your knowledge and comprehension of the subject, providing a comprehensive review of key concepts and reactions involving amines.
Class 12 Chemistry Amines MCQ with Answers
Ques 1. Which of the following is the most preferred reagent for reducing nitroethane to ethylamine?
a) Sn/HCl
b) Fe/HCl
c) H2/Pt
d) Zn/HCl
Answer: b
Ques 2. What is the correct name for a molecule that has two amino groups in opposing (para) locations around a benzene ring?
a) Benzene-1,4-diamine
b) p-Aminoaniline
c) 4-Aminobenzenamine
d) Benzenediamine
Answer: a
Ques 3. By reacting with which of the following, primary amines can be separated from secondary and tertiary amines?
a) Chloroform and alcoholic KOH
b) Zinc dust
c) Methyl iodide
d) Chloroform alone
Answer: a
Ques 4. The aromatic primary amine with the formula C7H9N has an incorrect name.
a) Phenylmethanamine
b) Benzylamine
c) Benzenamine
d) Phenylaminomethane
Answer: c
Ques 5. Which test can tell the difference between p-chloroaniline and anilinium hydrochloride?
a) Carbylamine test
b) AgNO3
c) NaHCO3
d) Sandmeyer reaction
Answer: c
Ques 6. Which of the following is formed when an alkyl primary amine reacts with nitrous acid?
a) Alcohol
b) Alkyl nitrite
c) Nitroalkane
d) Secondary amine
Answer: a
Ques 7. What is the most basic aromatic amine’s common name?
a) Benzenamine
b) Benzylamine
c) Aminobenzene
d) Aniline
Answer: d
Also Check: Important Questions for Class 12 Chemistry Chapter 13 Amines
Ques 8. When acetamide is converted to methylamine, what is the name of the reaction?
a) Hinsberg reaction
b) Friedel-Craft’s reaction
c) Hofmann reaction
d) Hoffmann bromamide degradation reaction
Answer: d
Ques 9. For which of the following is the Hinsberg approach used?
a) Preparation of primary amines
b) Preparation of secondary amines
c) Separation of amine mixtures
d) Preparation of tertiary amines
Answer: c
Ques 10. The conversion of benzene diazonium chloride to bromobenzene can be accomplished by
a) Friedel-Crafts reaction
b) Reimer-Tiemann reaction
c) Azo-Coupling reaction
d) Gattermann reaction
Answer: d
Ques 11. Which of the following amines are insoluble in water?
a) Propanamine
b) Benzenamine
c) Ethanamine
d) Methanamine
Answer: b
Ques 12. The best reagent for converting 2-phenylpropanamide into 2-phenylpropanamine is:
a) LiAlH4 in ether
b) Br2 in aqueous NaOH
c) iodine in the presence of red phosphorus
d) excess H2
Answer: a
Ques 13. Amongst the given set of reactants, the most appropriate for preparing 2° amine is:
a) 2° R—Br + NaCN followed by H2/Pt
b) 1° R—Br (2 mol) + potassium phthalimide followed by H3O+/heat
c) 2° R—Br + NH3
d) 1° R—NH2 + RCHO followed by H2/Pt
Answer: d
Ques 14. Which of the following statements about primary amines is false?
a) Alkylamines are stronger bases than arylamines.
b) Alkylamines react with nitrous acid to produce alcohols.
c) Alkylamines are stronger bases than ammonia.
d) Arylamines react with nitrous acid to produce phenols.
Answer: d
Ques 15. Reduction of CH3CH2NC with hydrogen in presence of Ni or Pt as catalyst gives
a) CH3CH2NHCH2CH3
b) CH3CH2NHCH3
c) CH3CH2NH2
d) (CH3)3N
Answer: b
Ques 16. The correct IUPAC name for CH2=CHCH2NHCH3 is
a) 2-amino-4-pentene
b) Allylmethylamine
c) 4-aminopent-1-ene
d) N-methylprop-2-en-1-amine
Answer: d
Ques 17. The best reagent for converting, 2-phenylpropanamide into 1-phenylethanamine is:
a) LiAlH4/ether
b) NaOH/Br2
c) NaBH4/methanol
d) excess H2/Pt
Answer: b
Also Check: Amines Structure
Ques 18. Amongst the following, the strongest base in aqueous medium is:
a) (CH3)2NH
b) C6H5NHCH3
c) NCCH2NH2
d) CH3NH2
Answer: a
Ques 19. Hoffmann bromamide degradation is used for the preparation of
a) secondary amines
b) secondary aromatic amines
c) tertiary amines
d) primary amines
Answer: d
Ques 20. Which of the following does not react with Hinsberg reagent?
a) CH3CH(NH2)CH3
b) C2H5NH2
c) (CH3)2NH
d) (CH3)3N
Answer: d
Ques 21. The source of nitrogen in Gabriel synthesis of amines is:
a) Sodium nitrite, NaNO2
b) Sodium azide, NaN3
c) Potassium cyanide, KCN
d) Potassium phthalimide, C6H4(CO)2N–K+
Answer: d
Ques 22. What compound is formed when hydrogen gas is passed through nitrobenzene in the presence of finely divided nickel?
a) 4-Nitroaniline
b) 3-Nitroaniline
c) 2-Nitroaniline
d) Aniline
Answer: d
Ques 23. How many water molecules are formed as the by-product of the reduction of one molecule of nitropropane to one molecule of propanamine, with hydrogen gas in Pt catalyst?
a) 2
b) 3
c) 4
d) 1
Answer: a
Ques 24. Ammonolysis is a type of _________ reaction.
a) electrophilic substitution
b) nucleophilic addition
c) electrophilic addition
d) nucleophilic substitution
Answer: d
Ques 25. What is the type of amine obtained from the ammonolysis of alkyl halides?
a) Primary and secondary
b) Primary
c) Secondary and tertiary
d) Primary, secondary and tertiary
Answer: d
Ques 26. What is the most suitable condition for the ammonolysis of an alkyl halide?
a) 273K, sealed tube
b) 373K, open tube
c) 373K, sealed tube
d) 273K, open tube
Answer: c
Ques 27. Aniline can be formed from the ammonolysis of chlorobenzene.
a) True
b) False
Answer: b
Ques 28. The main product formed when the ammonolysis is carried out using excess of iodoethane is _______
a) 3° amine
b) 2° amine
c) 1° amine
d) quaternary ammonium salt
Answer: d
Ques 29. What is the correct order of reactivity of the following alkyl halides towards ammonolysis reaction?
a) CH3Cl > CH3Br > CH3I
b) CH3I > CH3Br > CH3Cl
c) CH3Br > CH3Cl > CH3I
d) CH3I > CH3Cl > CH3Br
Answer: b
Ques 30. Ammonolysis is a reaction between an alkyl halide and most preferably an ______ solution of NH3.
a) aqueous
b) alcoholic
c) acidic
d) alkaline
Answer: b
Also Check: Amines Class 12 Notes Chemistry Chapter 13
Ques 31. Amines play an important role in the survival of life. Naturally, they are found in:
a) Vitamins
b) Alkaloids
c) Proteins
d) All of these
Answer: d
Ques 32. Propionamide on Hofmann degradation gives:
a) ethylamine
b) methylamine
c) propylamine
d) ethyl cyanide
Answer: a
Ques 33. Secondary amines could be prepared by:
a) Reduction of nitriles
b) Reduction of isonitriles
c) Hofmann bromamide reaction
d) Reduction of amides
Answer: b
Ques 34. Gabriel’s phthalimide synthesis is used for the preparation of:
a) Primary aromatic amines
b) Secondary amines
c) Tertiary amines
d) Primary aliphatic amines
Answer: d
Ques 35. Treatment of ammonia with excess of ethyl iodide will yield:
a) Diethylamine
b) Triethylamine
c) Ethylamine
d) Tetraethylammonium iodide
Answer: d
Ques 36. The reduction of nitro compounds is most preferred in the presence of:
a) Sn + HCl
b) Finely divided Ni
c) Pd/H2 in ethanol
d) Iron scrap and HCl
Answer: d
Ques 37. An alkyl or benzyl halide on reaction with an ethanolic solution of ammonia undergoes:
a) Nucleophilic addition reaction
b) Electrophilic substitution reaction
c) Nucleophilic substitution reaction
d) Free radical mechanism
Answer: c
Ques 38. Which of the following will give primary amine only?
a) Potassium phthalimide + chlorobenzene
b) Ammonia + propyl chloride
c) Potassium phthalimide + ethyl chloride
d) (i) and (ii)
Answer: b
Ques 39. Amines have:
a) Jasmine odour
b) Bitter almonds odour
c) Garlic odour
d) Fishy odour
Answer: d
Ques 40. Amines behave as:
a) Lewis acids
b) Lewis bases
c) Aprotic acids
d) Amphoteric compounds
Answer: b
Also Check: NCERT Solutions for Class 12 Chemistry Chapter 13 Amines
Ques 41. The basic character of amines is due to:
a) High electronegativity of nitrogen
b) Tetrahedral structure
c) Presence of nitrogen atom
d) Lone pair of electrons on nitrogen atom
Answer: d
Ques 42. Aliphatic amines are…..basic than NH3 but aromatic amines are……basic than NH3.
a) More, less
b) Less, more
c) Both (a) and (b)
d) None of these
Answer: a
Ques 43. Substitution of one alkyl group by replacing hydrogen of primary amines:
a) Remains the same
b) Decreases the base strength
c) None of the above
d) Increases the base strength
Answer: d
Ques 44. Which of the following is not characteristic of amines?
a) They turn red litmus blue
b) They smell like ammonia
c) They are amphoteric in nature
d) They show the property of hydrogen bonding
Answer: c
Ques 45. Which statement is not true among the following?
a) Trimethyl amine is less basic than dimethyl amine
b) Amines yield alcohols on aqueous hydrolysis
c) Amines are bases
d) They turn red litmus blue
Answer: b
Ques 46. Aniline is used:
a) In dyeing industry
b) In crimping of wool
c) In making of glue
d) In fast-drying varnish
Answer: a
Ques 47. Which of the following statements about primary amines is false?
a) Alkyl amines react with nitrous acid to produce alcohols
b) Aryl amines react with nitrous acid to produce phenols
c) Alkyl amines are stronger bases than ammonia
d) Alkyl amines are stronger bases than aryl amines
Answer: b
Ques 48. Mark the correct statement:
a) Methylamine forms salts with alkali
b) Methylamine is less basic than ammonia
c) Methylamine is a stronger base than ammonia
d) Methylamine is slightly acidic
Answer: c
Ques 49. For carbylamine reaction, we need hot alcoholic KOH and:
a) A primary amine and an alkyl halide
b) Chloroform and silver powder
c) Any primary amine and chloroform
d) A monoalkylamine and trichloromethane
Answer: c
