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Question
Write the structures of the main products when acetone (CH3 − CO − CH3) reacts with the following reagent :
H2N − NHCONH2/H+
Solution
Acetone reacts with semicarbazide to form semicarbazone.
RELATED QUESTIONS
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.
Write the main product formed when propanal reacts with the following reagents:
2 moles of 3 CH OH in presence of dry HCl
Acetone, Acetaldehyde, Benzaldehyde, Acetophenone – reactivity towards addition of HCN.
Which one of the following gives only one monochloro derivative?
Which of the following has the most acidic hydrogen?
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) |  |
Aldehydes and ketones react with hydroxylamine to form ______.
Draw 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
