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प्रश्न
What is meant by the following term? Give an example of the reaction in the following case.
Ketal
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उत्तर
Ketals are cyclic products formed by the reaction of ketones with ethylene glycol in the presence of dry HCl gas.
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संबंधित प्रश्न
How are the following compounds prepared?
benzaldehyde from benzene
What is meant by the following term? Give an example of the reaction in the following case.
Acetal
What is meant by the following term? Give an example of the reaction in the following case.
Semicarbazone
What is meant by the following term? Give an example of the reaction in the following case.
Hemiacetal
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.
PhMgBr and then H3O+
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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
Which of the following compounds is most reactive towards nucleophilic addition reactions?
Which will undergo faster nucleophilic addition reaction?
Acetaldehyde or Propanone
In the following reaction
\[\ce{Carbonyl compound + MeOH <=>[HCl] acetal}\]
Rate of the reaction is the highest for ______.
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) |  |
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.
Imine
