Amines Mock Test – Class 12 Chemistry

1. Amide reduction and nitrile reduction are similar in that:

2. A benzene ring carries at carbon , chlorine at carbon , and methyl at carbon . The name is:

3. Assertion: Molecular nitrogen is an excellent leaving group in reactions of arenediazonium salts.
Reason: is a highly stable neutral molecule, so its formation provides a strong driving force for loss of the diazonium group.

4. An organic solution contains a neutral amine mixed with a neutral hydrocarbon. Shaking the solution with dilute hydrochloric acid transfers the amine mainly into the aqueous layer because:

5. Examine the Hoffmann-degradation products below.

The valid row is:

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

7. In an arenediazonium ion, the charge on the group is ______.

8. Reduction of with gives:

9. The preferred conditions for preparing a primary alkylamine by ammonolysis of a haloalkane are:

10. From the Lewis acid–base viewpoint, a neutral amine is classified as a Lewis base because it:

11. Complete conversion of of an unknown monofunctional amine gives its hydrochloride. The isolated hydrochloride weighs , and the isolation yield is . Assuming one mole of amine binds one mole of hydrochloric acid, the amine is:

12. Which species is least able to accept another proton through nitrogen under ordinary conditions?

13. Assertion: Many azo compounds are strongly coloured.
Reason: Their aromatic rings and azo linkage form an extended conjugated system capable of absorbing visible light.

14. Complete the balanced carbylamine equation:

The missing coefficient is:

15. In the balanced overall equation

the missing coefficient of is:

16. Consider the following statements about nitrile reduction.
Statement I: can reduce a nitrile to a primary amine.
Statement II: Catalytic hydrogenation may also convert a nitrile into a primary amine.
Statement III: The nitrile carbon is lost during the reduction.
Select the applicable combination.

17. Which decreasing order of electrophilic-substitution reactivity is most reasonable under conditions where each species remains mainly in the form shown?

18. Use the following passage.
An ortho substituent can twist an amino group away from perfect conjugation with the aromatic ring. Such twisting may make the nitrogen lone pair more localised. The same substituent can also obstruct proton approach and hydration of the conjugate acid.
Which conclusion follows most appropriately?

19. Examine the structural descriptions below.

The correctly classified row is:

20. Base P has , and base Q has . The ratio is:

21. Assertion: Protonation generally decreases the nucleophilicity of an amine nitrogen.
Reason: The lone pair used for nucleophilic attack becomes part of the new nitrogen–hydrogen bond.

22. Ethane-1,2-diamine, , is accurately described as:

23. An organic mixture of mass contains aniline and a neutral compound. The aniline is completely extracted as its hydrochloride, regenerated with base, and isolated. The recovered aniline has a mass of , corresponding to an overall recovery. The original mass percentage of aniline and the minimum volume of hydrochloric acid required for extraction are:

24. Examine the diazotisation records below.

The valid row is:

25. Cyclohexylamine is much more basic than aniline even though both compounds contain a six-membered carbon ring. The decisive difference is that:

26. A sample of ethylamine is treated with nitrous acid. Only of the amine reacts, and of the nitrogen formed is collected over water at . The total pressure is , and the vapour pressure of water is . Calculate the collected wet-gas volume. Use and .

27. Assertion: Strongly acidifying an aniline coupling mixture can decrease the yield of the azo product.
Reason: Protonation converts aniline into anilinium ion, whose ring is less activated toward electrophilic coupling.

28. Protonation of dimethylamine produces:

29. Assertion: The carbon skeleton of the migrating group remains intact during Hoffmann rearrangement.
Reason: The group migrates with its bonding electron pair from the carbonyl carbon to nitrogen.

30. For a saturated acyclic monoamine containing carbon atoms, the molecular formula is completed by ______.

31. The structure corresponding to -ethyl--methylbutan-1-amine is:

32. Examine the coupling records below.

The valid rows are:

33. Assertion: Reduction of benzamide gives benzylamine rather than aniline.
Reason: The carbonyl carbon of benzamide is retained and becomes the group between the phenyl ring and nitrogen.

34. Use the inversion pathway described below. A pyramidal amine begins with nitrogen above the plane defined by its three substituents, passes through an intermediate arrangement, and ends with nitrogen below that plane. The correct interpretation is:

35. Dimethylamine gives a negative carbylamine test because:

36. An unknown amine forms no sulphonamide with Hinsberg reagent, remains unreacted in excess alkali, and dissolves when dilute acid is added. The amine is:

37. A neutral nitrogen atom in an ordinary amine is most consistently described as having:

38. A graph compares aqueous basicity for a series of corresponding ortho- and para-substituted anilines as substituent bulk increases. If electronic effects are otherwise similar, the most likely trend is:

39. Examine the formulas below.

The valid rows are:

40. Addition of can reduce the electrophilic-substitution reactivity of aniline because:

41. A compound with structure has been named -aminobutane. When the amine is treated as the principal functional group, the preferred repair is:

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

43. Comparing the usual aqueous orders of methylamines and ethylamines shows that:

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

45. A graph plots moles of phenol formed against moles of benzenediazonium chloride warmed in excess water. The hydrolysis is quantitative. The graph shows:

46. -Methoxyaniline is generally more basic than aniline because the para methoxy group:

47. Use the following passage.
A student argues that trimethylamine must be the strongest methylamine in water because it has three electron-releasing methyl groups. Another student points out that aqueous basicity depends on the stability of both the neutral base and its protonated form.
Which observation most directly supports the second student?

48. A student wants to prepare by reducing an amide. The most suitable starting amide is:

49. To prepare propan-1-amine, the appropriate starting amides for reduction and Hoffmann degradation, respectively, are:

50. A molecular model shows nitrogen bonded to three groups, with all three groups lying in one plane and no fourth electron domain represented. The main defect in this model of an ordinary neutral amine is that it: