Assertion (A): Diazonium salts of aromatic amines are more stable than those of aliphatic amines.
Reason (R): Diazonium salts of aromatic amines undergo resonance.
Reason (R): Diazonium salts of aromatic amines undergo resonance.
Show Hint
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
The Correct Option is A
Solution and Explanation
Diazonium salts contain the $-N_2^+$ group. Their stability determines how long they can persist in solution.
Step 2: Analysis
Aromatic diazonium salts (e.g., $C_6H_5N_2^+$) are relatively stable because the positive charge on the nitrogen is delocalized through resonance with the benzene $\pi$-system. The electrons from the benzene ring donate into the diazonium group, stabilizing it. Aliphatic diazonium salts lack this resonance stabilization and decompose almost instantly.
Step 3: Conclusion
Both the Assertion (stability of aromatic diazonium salts) and the Reason (resonance stabilization) are true, and the resonance is precisely the reason for this enhanced stability.
Final Answer: (A)
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Top CBSE CLASS XII Amines Questions
Write IUPAC names of the following compounds and classify them into primary, secondary and tertiary amines.
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Arrange the following:
(i) In decreasing order of the pKb values: C2H5NH2 , C6H5NHCH3 , (C2H5 )2NH and C6H5NH2
(ii) In increasing order of basic strength: C6H5NH2 , C6H5N(CH3 )2 , (C2H5 )2NH and CH3NH2
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How will you convert:
(i) Ethanoic acid into methanamine
(ii) Hexanenitrile into 1-aminopentane
(iii) Methanol to ethanoic acid
(iv) Ethanamine into methanamine
(v) Ethanoic acid into propanoic acid
(vi) Methanamine into ethanamine
(vii) Nitromethane into dimethylamine
(viii) Propanoic acid into ethanoic acid?
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