Give plausible explanation for the following:
(a) Diazonium salts of aromatic amines are stable.
(b) Aniline does not undergo Friedel–Crafts reaction.
(c) Aniline on nitration gives a substantial amount of meta product.
(b) Aniline does not undergo Friedel–Crafts reaction.
(c) Aniline on nitration gives a substantial amount of meta product.
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Solution and Explanation
(a) Stability due to resonance and delocalization of \(\ce{N_2^+}\) over benzene ring. (b) Aniline forms a Lewis acid–base complex with AlCl\(_3\) → deactivates ring. (c) In acidic medium, aniline gets protonated to \(\ce{Ph–NH3^+}\), a meta-directing group. \[ \boxed{\text{Acidic conditions lead to meta product due to protonation}} \]
Top Questions on Amines
- Hoffmann Bromamide degradation reaction is given by:
- An amine 'X' reacts with Hinsberg reagent and the product obtained is soluble in alkali. The amine 'X' is:
- Arrange the following compounds as asked:
(a) In decreasing order of pKb, values: C$_6$H$_5$NH$_2$, (C$_2$H$_5$)$_2$NH, C$_6$H$_5$NHCH$_2$CH$_3$, C$_6$H$_5$NH$_3$
(b) Increasing order of boiling point: C$_6$H$_5$OH, C$_2$H$_5$NH$_2$, (C$_2$H$_5$)$_2$NH, C$_6$H$_5$NH$_2$
(c) Increasing order of solubility in water: C$_6$H$_5$NH$_2$, (C$_2$H$_5$)$_2$NH, C$_6$H$_5$NHCH$_2$CH$_3$ - Give plausible explanation for each of the following:
Amides are less basic than amines. Amines are usually formed from amides, imides, halides, nitro compounds, etc. They exhibit hydrogen bonding which influences their physical properties. In alkyl amines, a combination of electron releasing, steric and H-bonding factors influence the stability of the substituted ammonium cations in protic polar solvents and thus affect the basic nature of amines. Alkyl amines are found to be stronger bases than ammonia. Amines being basic in nature, react with acids to form salts. Aryldiazonium salts, undergo replacement of the diazonium group with a variety of nucleophiles to produce aryl halides, cyanides, phenols and arenes.
How can you convert the following:
(i) Ethanoic acid to methanamine
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Solve the following LPP graphically: Maximize: \[ Z = 2x + 3y \] Subject to: \[ \begin{aligned} x + 4y &\leq 8 \quad \text{(1)} \\ 2x + 3y &\leq 12 \quad \text{(2)} \\ 3x + y &\leq 9 \quad \text{(3)} \\ x &\geq 0,\quad y \geq 0 \quad \text{(non-negativity constraints)} \end{aligned} \]
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