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प्रश्न
What is meant by the following term? Give an example of the reaction in the following case.
Semicarbazone
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उत्तर
Semicarbazones are derivatives of aldehydes and ketones produced by the condensation reaction between a ketone or aldehyde and semicarbazide.
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संबंधित प्रश्न
Arrange the following compound in increasing order of its reactivity in nucleophilic addition reactions.
Ethanal, Propanal, Propanone, Butanone.
Hint: Consider steric effect and electronic effect.
Predict the product of the following reaction:
What is meant by the following term? Give an example of the reaction in the following case.
Schiff’s base
Write balanced chemical equations for action of ammonia on - acetone
Which of the following compounds is most reactive towards nucleophilic addition reactions?
Acetaldehyde and acetone differ in their reaction with
The product of following reaction is
\[\ce{CH3 - CH = CH - CH2 - CHO ->[i) LiAlH4][ii) H3O+]}\] ______?
Which of the following is most reactive in nucleophilic addition reactions?
The following questions are case-based questions. Read the passage carefully and answer the questions that follow:
| The carbon-oxygen double bond is polarised in aldehydes and ketones due to higher electronegativity of oxygen relative to carbon. Therefore, they undergo nucleophilic addition reactions with a number of nucleophiles such as HCN, NaHSO3, alcohols, ammonia derivatives and Grignard reagents. Aldehydes are easily oxidised by mild oxidising agents as compared to ketones. The carbonyl group of carboxylic acid does not give reactions of aldehydes and ketones. Carboxylic acids are considerably more acidic than alcohols and most of simple phenols. |
Answer the following:
(a) Write the name of the product when an aldehyde reacts with excess alcohol in the presence of dry HCl. (1)
(b) Why carboxylic acid is a stronger acid than phenol? (1)
(c) (i) Arrange the following compounds in increasing order of their reactivity towards CH3MgBr: (1)
CH3CHO, \[\begin{array}{cc}
\ce{(CH3)3C-C-CH3}\\
\phantom{....}||\\
\phantom{....}\ce{O}
\end{array}\], \[\begin{array}{cc}
\ce{CH3-C-CH3}\\
||\\
\ce{O}
\end{array}\]
(ii) Write a chemical test to distinguish between propanal and propanone. (1)
OR
(c) Write the main product in the following: (2)
| (i) |  |
| (ii) |  |
Out of p-tolualdehyde and p-nitrobenzaldehyde, which one is more reactive towards nucleophilic addition reactions, why?
Draw structure of the following derivative.
Acetaldehydedimethylacetal
Why dissociation of HCN is suppressed by the addition of HCL?
The product of the following reaction is
\[\begin{array}{cc}
\ce{O}\phantom{.........}\\
||\phantom{.........}\\
\ce{C2H5 - C - CH3 ->[H2/Ni][\Delta] \phantom{..}?}\end{array}\]
Draw the structure of the following derivative.
The ethylene ketal of hexan-3-one
Draw the structure of the following derivative.
The ethylene ketal of hexan-3-one
Draw the structure of the following derivative.
Acetaldehydedimethylacetal
Draw structure of the following derivative.
The ethylene ketal of hexan-3-one
Draw the structure of the given derivative.
The ethylene ketal of hexan-3-one
Give an example of the reaction in the following case.
Oxime
