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प्रश्न
Give plausible explanation for the following:
There are two −NH2 groups in semicarbazide. However, only one is involved in the formation of semicarbazones.
उत्तर
Semicarbazide only has one of the two −NH2 groups resonance and this group is directly attached to the carbonyl-carbon atom.
Therefore, the electron density on −NH2 group involved in the resonance also decreases. As a result, it cannot act as a nucleophile. Since the other −NH2 group is not involved in resonance, it can act as a nucleophile and attack carbonyl-carbon atoms of aldehydes and ketones to produce semicarbazones.
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संबंधित प्रश्न
Predict the product of the following reaction:
\[\begin{array}{cc}
\phantom{..............}\ce{O}\\
\phantom{..............}||\\
\ce{R - CH = CH - CHO + NH2 - C - NH - NH2 ->[H+]}\end{array}\]
What is meant by the following term? Give an example of the reaction in the following case.
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What is meant by the following term? Give an example of the reaction in the following case.
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(ii) 
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| (ii) |  |
| (iii) |  |
| (iv) |  |
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\[\begin{array}{cc}
\ce{O}\phantom{.........}\\
||\phantom{.........}\\
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