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प्रश्न
The presence of nitro group (−NO2) at o/p positions increases the reactivity of haloarenes towards nucleophilic substitution reactions.
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उत्तर
The presence of nitro groups (−NO2) at o/p positions increases the reactivity of haloarenes towards nucleophilic substitution reactions because nitro groups (−NO2) at o/p positions withdraw the electron density from the benzene ring facilitating the attack of the nucleophile. The negative charge in the carbanion formed, at ortho and para positions with respect to halogen atom, is stabilised through resonance and the presence of nitro groups (−NO2), respectively.
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संबंधित प्रश्न
Chlorobenzene is extremely less reactive towards a nucleophilic substitution reaction. Give two reasons for the same.
What is Grignard reagent?
Assertion: Presence of a nitro group at ortho or para position increases the reactivity of haloarenes towards nucleophilic substitution.
Reason: Nitro group, being an electron-withdrawing group decreases the electron density over the benzene ring.
Which of the following compounds will give racemic mixture on nucleophilic substitution by \[\ce{OH-}\] ion?
(a) \[\begin{array}{cc}
\phantom{}\ce{CH3 - CH - Br}\\
\phantom{}|\\
\phantom{....}\ce{C2H5}\phantom{}
\end{array}\]
(b) \[\begin{array}{cc}
\phantom{..}\ce{Br}\\
\phantom{}|\\
\phantom{}\ce{CH3 - C - CH3}\\
\phantom{}|\\
\phantom{....}\ce{C2H5}\phantom{}
\end{array}\]
(c) \[\begin{array}{cc}
\phantom{....}\ce{CH3 - CH - CH2Br}\\
\phantom{}|\\
\phantom{....}\ce{C2H5}\phantom{}
\end{array}\]
Arrange the following compounds in increasing order of rate of reaction towards nucleophilic substitution.
| (a) |  |
| (b) |  |
| (c) |  |
Arrange the following compounds in increasing order of rate of reaction towards nucleophilic substitution.
| (a) |  |
| (b) |  |
| (c) |  |
Arrange the following compounds in increasing order of rate of reaction towards nucleophilic substitution.
| (a) |  |
| (b) |  |
| (c) |  |
\[\ce{C6H12O6 ->[(Zymase)] A ->[NaOH][\Delta] B + CHI3}\]
The number of carbon atoms present in the product B is:
Why haloarenes are not reactive towards nucleophilic substitution reaction? Give two reactions.
Identify the final product [D] obtained in the following sequence of reactions.
\[\ce{CH3CHO \underset{ii) H2O+}{\overset{i) LiAlH4}{->}} [A] \underset{\triangle}{\overset{H2SO4}{->}} [B]}\]
