JEE Main - Diazonium salts and their synthetic importance One Line Questions & Answers

1. The product of an azo coupling reaction contains the characteristic functional group: — -N=N-

2. What is the oxidation state of nitrogen in the diazonium group (-N₂⁺)? — +1

3. The reaction of a primary aromatic amine with nitrous acid in the presence of a mineral acid at low temperature (0-5 °C) yields: — A diazonium salt

4. The Sandmeyer reaction involves the conversion of a diazonium salt to: — A halobenzene using CuX (X = Cl, Br)

5. Diazonium salts are important intermediates in the synthesis of: — A wide range of substituted aromatic compounds

6. Azo coupling reactions typically occur between a diazonium salt and: — An activated aromatic compound (like phenol or aniline)

7. The reduction of diazonium salts with hypophosphorous acid (H₃PO₂) leads to the formation of: — Aromatic hydrocarbons

8. The reaction of diazonium salts with ethanol can lead to: — Aromatic hydrocarbons and nitrogen gas

9. In the Schiemann reaction, the diazonium salt is first treated with HBF₄ to form a diazonium tetrafluoroborate salt, which is then heated. This leads to the formation of: — Aryl fluoride

10. The Balz-Schiemann reaction is specifically used for the synthesis of: — Aryl fluorides

11. The coupling of a diazonium salt with a compound containing an active methylene group is possible under specific conditions. This is an example of: — Azo coupling

12. Which reaction is most suitable for synthesizing fluorobenzene from aniline? — Balz-Schiemann reaction

13. The reaction of benzenediazonium chloride with H₃PO₂ yields: — Benzene

14. The reaction of benzenediazonium chloride with sodium borohydride (NaBH₄) can lead to: — Benzene

15. When benzenediazonium chloride is treated with ethanol, the major products are: — Benzene and nitrogen gas

16. When benzenediazonium chloride reacts with CuCN/KCN, the product is: — Benzonitrile

17. The conversion of a diazonium salt to an aryl boronic acid can be achieved using: — Boric acid and a base

18. Which product is formed when benzenediazonium chloride reacts with CuBr/HBr? — Bromobenzene

19. In the Sandmeyer reaction, what is the role of copper(I) halide (CuX)? — Catalyst for the replacement of the diazonium group by halide

20. Which product is formed when benzenediazonium chloride reacts with CuCl/HCl? — Chlorobenzene

21. The Gattermann reaction is similar to the Sandmeyer reaction but uses: — Copper powder and the corresponding acid (e.g., Cu/HCl)

22. The replacement of the diazonium group by a cyano group (-CN) can be achieved using: — CuCN/KCN

23. The azo coupling reaction is characteristic of: — Diazonium salts

24. The synthesis of 4-bromobenzoic acid from 4-aminobenzoic acid involves: — Diazotization followed by Sandmeyer reaction

25. Diazonium salts are typically prepared from primary aromatic amines by treatment with: — Dilute HCl and NaNO₂

26. Azo compounds are known for their use as: — Dyes

27. In the azo coupling reaction, the diazonium ion acts as an: — Electrophile

28. Which of the following is a characteristic property of diazonium salts that enables their use in coupling reactions? — Electrophilic nature of the diazonium ion

29. The reaction of a diazonium salt with sodium nitrite in the presence of copper powder can introduce a nitro group into the aromatic ring. This is a variation of: — Gattermann reaction

30. The Sandmeyer reaction is a method for the replacement of the diazonium group by: — Halogens or cyano group

31. Which of the following is used in the Schiemann reaction to introduce fluorine into the aromatic ring? — HBF₄

32. The replacement of the diazonium group by a hydrogen atom can be achieved using: — Hypophosphorous acid (H₃PO₂)

33. The reaction of benzenediazonium chloride with potassium iodide (KI) yields: — Iodobenzene

34. Which reagent is used to convert aniline to benzenediazonium chloride? — NaNO₂ + HCl (0-5 °C)

35. The decomposition of diazonium salts in solution is an example of: — Nucleophilic substitution

36. When benzenediazonium chloride couples with aniline in a weakly acidic medium, the product formed is: — p-Aminoazobenzene

37. When benzenediazonium chloride couples with phenol in alkaline medium, the product formed is: — p-Hydroxyazobenzene

38. When benzenediazonium chloride is heated with water, the primary product formed is: — Phenol

39. Which of the following is NOT a synthetic application of diazonium salts? — Preparation of alkenes

40. Which of the following is the general formula for diazonium salts? — R-N≡N⁺ X⁻

41. The synthesis of substituted benzoic acids from substituted anilines often involves diazotization followed by: — Reaction with CuCN/KCN and subsequent hydrolysis

42. Which of the following diazonium salt reactions is used to introduce an iodine atom into an aromatic ring? — Reaction with KI

43. Which of the following diazonium salt reactions results in the formation of nitrogen gas as a byproduct? — All of the above

44. The conversion of a diazonium salt to an aryl fluoride is known as the: — Balz-Schiemann reaction

45. What is the primary reason for the synthetic utility of diazonium salts? — The diazonium group can be easily replaced by a variety of nucleophiles

46. The reason for the instability of diazonium salts is: — The strong tendency of the N₂ molecule to leave as a stable gas

47. Which of the following is a characteristic property of diazonium salts in aqueous solution? — They are generally unstable and decompose readily

48. Why is the preparation of diazonium salts carried out at low temperatures (0-5 °C)? — To prevent decomposition of the diazonium salt

49. Azo coupling reactions are usually carried out in a medium that is: — Weakly acidic or weakly alkaline

Diazonium salts and their synthetic importance - One Line Questions