CBSE 12th Aldehydes, Ketones And Carboxylic Acid Important Questions 2025

1

The formation of cyanohydrin from an aldehyde is an example of?

2

Write the chemical equation when :

• Butan-2-one is treated with Zn(Hg) and conc. HCl.
• Two molecules of benzaldehyde are treated with conc. NaOH.

3

Compound (A) (CH,202) on reduction with LiAlH4 gives two compounds (B) and (C). The compound (B) on oxidation with PCC gives compound (D) which upon treatment with dilute NaOH and subsequent heating gives compound (E). Compound (E) on catalytic hydrogenation gives compound (C). The compound (D) is oxidized further to give compound (F) which is found to be a monobasic acid (Molecular weight = 60). Identify the compounds (A), (B), (C), (D), (E) and (F).

4

What happens when benzene is treated with CH,COC in presence of anhydrous AlCl3?

5

How can you convert the following: Benzene to acetophenone?

6

Write a chemical equation for the following reaction: Benzoyl chloride is hydrogenated in presence of Pd/BaS04.

7

Write the equation involved in the following reaction: 

• Etard reaction
• Stephen reaction

8

How do you convert the following: Ethyne to ethanal

9

What happens when Propanone is treated with methyl magnesium iodide and then hydrolysed?

10

How can you convert the following: Acetone to propene? OR

Do the following conversion in not more than two steps: Propanone to propene

11

Give simple chemical tests to distinguish between the following pair of  compounds: 

• Ethanal and propanal
• Benzaldehyde and acetophenone.

12

Explain the following reactions:

• Wolff-Kishner reduction
• Cannizzaro reaction

13

An organic compound 'A' having the molecular formula C3H80 on treatment with Cu at 573 K, gives 'B'. 'B' does not reduce Fehling's solution but gives a yellow precipitate of the compound 'C' with Iz/NaOH. Deduce the structures of A, B and С.

14

An alkene A with molecular formula CH10 on ozonolysis gives a mixture of two compounds, B and C. Compound B gives a positive Fehling's test and also reacts with iodine and NaOH solution. Compound C does not give the Fehling solution test but forms an iodoform. Identify the compounds A, B and C.

15

(A), (B) and (C) are three non-cyclic functional isomers of a carbonyl compound with molecular formula C,HgO. Isomers (A) and (C) give positive Tollens test whereas isomer (B) does not give Tollens' test but gives positive iodoform test. Isomers (A) and (B) on reduction with Zn(Hg)/conc. HCI gives the same product (D).

a) Write the structures of (A), (B), (C) and (D).

b) Out of (A), (B) and (C) isomers, which one is least reactive towards addition of HCN?