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प्रश्न
Complete the synthesis by giving missing starting material, reagent or product.
\[\ce{C6H5CHO ->[H2NCONHNH2]}\]
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उत्तर १
\[\begin{array}{cc}
\phantom{....................................}\ce{O}\\
\phantom{....................................}||\\
\ce{\underset{Benzaldehyde}{C6H5CHO} + \underset{Semicarbazide}{H2NCONHNH2} -> C6H5CH \underset{Benzaldehyde semicarbazide}{= NNHC - NH2} + H2O}\end{array}\]
उत्तर २
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संबंधित प्रश्न
Acetaldehyde, when treated with which among the following reagents does NOT undergo addition reaction?
(A) Ammonia
(B) Hydroxylamine
(C) Ammoniacal silver nitrate
(D) Semicarbazide
Arrange the following in the increasing order of their reactivity towards nucleophilic addition reaction:
C6H5COCH3, CH3-CHO, CH3COCH3
Draw the structure of the semicarbazone of ethanal.
Predict the product of the following reaction:
What is meant by the following term? Give an example of the reaction in the following case.
Cyanohydrin
What is meant by the following term? Give an example of the reaction in the following case.
Schiff’s base
Predict the products formed when cyclohexanecarbaldehyde reacts with the following reagents.
Semicarbazide and weak acid
Write balanced chemical equations for action of ammonia on - acetone
What is the action of the following reagents on ethanoic acid?
1) `LiAlH_4"/"H_3O^+`
2) `PCl_3 , "heat"`
3) `P_2O_5, "heat"`
Write the main product formed when propanal reacts with the following reagents:
2 moles of 3 CH OH in presence of dry HCl
Write the main product formed when propanal reacts with the following reagents:
H2N- NH2 followed by heating with KOH in ethylene glycol.
Which of the following is the correct representation for intermediate of nucleophilic addition reaction to the given carbonyl compound (A):
(i) 
(ii) 
(iii) 
(iv) 
Which of the following has the most acidic hydrogen?
What happens when propanone is treated with CH3MgBr and then hydrolysed?
What happens when ethanal is treated with excess ethanol and acid?
Which will undergo faster nucleophilic addition reaction?
Acetaldehyde or Propanone
The product "P" in the above reaction is:
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) |  |
Draw structures of the given derivatives.
The ethylene ketal of hexan-3-one
