✓ Board-verified
Chemistry · 2025 · 3 marks
CBSE 2025 · Region 1 · Set 2 · Q24
(a) Arrange the following in decreasing order of pK_b: Aniline, p-nitroaniline, p-methylaniline (b) Account for the following: (i) Diazonium salts of…
(a)
Arrange the following in decreasing order of $\displaystyle \mathrm{pK}_{\mathrm{b}}$ : Aniline, p-nitroaniline, p-methylaniline
(b)
Account for the following :
(i)
Diazonium salts of aromatic amines are more stable than those of aliphatic amines.
(ii)
Methylamine in water reacts with $\displaystyle \mathrm{FeCl}_{3}$ to precipitate hydrated ferric oxide.
Marking-scheme solution
(a)
p-nitroaniline > Aniline > p-methylaniline
(b)(i)
Due to resonance stabilization.
(ii)
Methylamine in water acts as a base and release OH- ions which reacts with FeCl3 to
form hydrated ferric oxide. / chemical equation
More from Amines
- Assertion: Acetanilide ( -NHCOCH_3 ) is less basic than aniline. Reason (R): Acetylation of aniline results in decrease of electron density on…2024 · asked 2×
- Among the following, which is the strongest base?2023 · asked 2×
- Which of the following is least basic?2023
- Assertion: Aliphatic primary amines can be prepared by Gabriel phthalimide synthesis. Reason (R): Alkyl halides undergo nucleophilic substitution…2024
- How will you obtain the following from benzene diazonium chloride? Write chemical equations involved: 3 []2026
- A compound 'A' on reduction with iron scrap and hydrochloric acid gives compound 'B' with molecular formula C_6 H_7 N. Compound 'B' on reaction with…2022
- Assertion: Aniline is a stronger base than ammonia. Reason (R): The unshared electron pair on nitrogen atom in aniline becomes less available for…2024
- Identify the primary amine from the given options:2024
CBSE Class 12 Chemistry past-paper question from the 2025 board exam, with the answer as CBSE’s own marking scheme gives it. Where our answers come from.