Amines Mock Test – Class 12 Chemistry

1. Catalytic hydrogenation of nitrobenzene to aniline may be carried out using:

2. Consider the following statements about water solubility of neutral amines.
Statement I: Primary, secondary, and tertiary amines can accept hydrogen bonds from water.
Statement II: Solubility generally decreases as the hydrophobic carbon portion becomes larger.
Statement III: A tertiary amine must contain an bond to dissolve in water.
Select the applicable combination.

3. Assertion: The sulphonamide formed from a secondary amine remains insoluble when excess aqueous alkali is added.
Reason: The sulphonamide contains no nitrogen-bonded hydrogen that can be removed by the alkali.

4. The amino group directs an incoming electrophile mainly to the ortho and para positions because attack at these positions:

5. A sample of aniline undergoes the following sequence: is converted into acetanilide, of that material gives the desired -bromoacetanilide, and hydrolysis produces -bromoaniline in yield. Calculate the mass of -bromoaniline obtained and the amount of bromine consumed in the desired bromination step. Use , , and .

6. Match each Gabriel-synthesis limitation in Column I with its consequence in Column II.

7. Aniline is converted successively into acetanilide, mainly -nitroacetanilide, -nitroaniline, a diazonium salt, -nitrobenzonitrile, and finally a carboxylic acid. The final product is:

8. Assertion: The molecular formula can represent primary, secondary, and tertiary amines.
Reason: Three carbon atoms satisfy the minimum carbon requirements for all three amine degrees.

9. Examine the name–structure assignments below.

The valid rows are:

10. A mixture contains methylamine and dimethylamine. On complete carbylamine reaction, of isocyanide is formed. What is the mass percentage of methylamine in the mixture, and what mass of potassium hydroxide is theoretically consumed? Use and .

11. Consider the following statements about substituent effects on aromatic-amine basicity.
Statement I: Electron-donating substituents generally increase basicity.
Statement II: Electron-withdrawing substituents generally decrease basicity.
Statement III: The position of a substituent can determine whether its resonance effect directly influences the amino group.
Select the applicable combination.

12. In an important charge-separated resonance contributor of a primary amide :

13. Which reagent sequence converts nitrobenzene into phenol?

14. Examine the constant pairs below.

The internally consistent row is:

15. Assertion: Acidification of the alkaline solution obtained from a primary amine in the Hinsberg test produces a precipitate.
Reason: Acid converts the soluble sulphonamide salt back into the neutral, less water-soluble sulphonamide.

16. Interchanging the two ethyl groups in diethylamine does not produce a new constitutional isomer because:

17. Equal initial amounts of benzenediazonium ion and an aliphatic diazonium ion are maintained at the same low temperature. A graph plots the fraction of each ion remaining against time. Which description is most reasonable?

18. Conversion of -bromopropane into propan-1-amine by ammonolysis causes the total carbon count to:

19. Match each diazonium reagent or condition in Column I with its principal organic product in Column II.

20. Benzamide is treated successively with , cold , and . The principal final product is:

21. Which structural change is most likely to lower aqueous basicity when its electron-releasing effect is small but its steric effect near nitrogen is large?

22. Ethyl bromide is used in two routes.
Route I: direct ammonolysis with excess ammonia.
Route II: reaction with , followed by reduction of the nitrile.
The favoured primary-amine products from Routes I and II, respectively, are:

23. A weak amine solution is diluted so that its concentration becomes one-hundredth of its original value. If remains constant and the square-root approximation is valid, its hydroxide-ion concentration becomes:

24. Assertion: Direct nitration of aniline does not give only ortho- and para-nitroaniline.
Reason: The strongly acidic nitrating medium converts a significant fraction of aniline into anilinium ion, which is meta directing.

25. Examine the qualitative data below.

Which row gives a chemically reasonable balance of the stated factors?

26. A neutral amine is converted into its protonated ammonium ion. Its immediate nucleophilicity at nitrogen decreases mainly because:

27. Compare the two nitration procedures described below.
Two students nitrate equal amounts of aniline. Student P performs direct nitration in concentrated acids. Student Q first converts aniline into acetanilide, carries out nitration under controlled conditions, and finally hydrolyses the nitrated product. Student P obtains a mixture containing a substantial meta isomer, whereas Student Q obtains mainly one isomer.
The major final product obtained by Student Q is:

28. Benzamide is converted into aniline by Hoffmann degradation. The aniline is diazotised, treated with , and the nitrile is hydrolysed to benzoic acid. The carbon bookkeeping is:

29. Match each pair in Column I with the type of constitutional isomerism in Column II.

30. Which reagent sequence most suitably converts aniline into mainly -nitroaniline?

31. The name -dimethylaniline represents:

32. Conversion of a tertiary amine into the more water-soluble ionic form is represented by:

33. The relation between and is completed by

34. A solution initially contains each of aniline and ethylamine. Its is adjusted to . Given for anilinium ion and for ethylammonium ion, the approximate amounts present in protonated form are:

35. Assertion: Treatment of benzenediazonium chloride with hypophosphorous acid gives benzene.
Reason: Hypophosphorous acid reduces the diazonium group and replaces it by hydrogen without reducing the aromatic ring.

36. A mixture containing of ethylamine is treated with of ethanoyl chloride and of benzoyl chloride in the presence of excess sodium hydroxide. Both acyl chlorides react completely and selectively form the corresponding amides. Using molar masses for -ethylethanamide and for -ethylbenzamide, the total amide mass and the minimum sodium hydroxide mass consumed are:

37. Assertion: Aniline reacts rapidly with bromine water without addition of .
Reason: The amino group strongly activates the ring through resonance donation and stabilises the substitution intermediate.

38. The carbonyl carbon of an amide is isotopically labelled before Hoffmann degradation. The label will be found mainly:

39. Arenediazonium ions are more stable than comparable aliphatic diazonium ions mainly because:

40. The polarity of a carbon–nitrogen bond in an alkylamine is best represented as:

41. At , take . If an amine has , the of its conjugate acid is:

42. Dimethylamine gives a negative carbylamine test because:

43. For an ordinary neutral tertiary amine, the blank is filled by ______.

44. Ethylamine gives ethyl isocyanide rather than propanenitrile in the carbylamine reaction because:

45. A graph plots aromatic-amine basicity on the vertical axis and the electron-withdrawing strength of a para substituent on the horizontal axis. The expected overall trend is:

46. Nitrobenzene is converted into aniline in a molar ratio. What mass of aniline is obtained from of nitrobenzene at yield? Use molar masses for nitrobenzene and for aniline.

47. Ethyldimethylamine, , is classified as:

48. Which statement best expresses the limitation of the common rule that ortho-substituted anilines are less basic than their para isomers?

49. When of methylamine is mixed with of hydrochloric acid, neglecting the weak acidity of the methylammonium ion in the presence of excess strong acid, the is:

50. A sample of benzamide undergoes Hoffmann degradation with conversion to aniline. Diazotisation converts of the aniline formed, and Sandmeyer chlorination converts of the diazonium salt into chlorobenzene. Chlorobenzene is isolated in yield. Calculate the isolated chlorobenzene mass and the volume of nitrogen formed during the Sandmeyer step at STP. Use , , and at STP.