CBSE Class 12th Chemistry Chapter 8 - Aldehydes, Ketones and Carboxylic Acids Important Questions with Answers

(a) How will you convert:
(i) Benzene to acetophenone (ii) Propanone to 2-Methylpropan-2-ol
(b) Give reasons :
(i) Electrophilic substitution in benzoic acid takes place at meta position.
(ii) Carboxylic acids are higher boiling liquids than aldehydes, ketones and alcohols of comparable molecular masses.
(iii) Propanal is more reactive than propanone in nucleophilic addition reactions. (Comptt. Delhi 2017)

(a) Write the products of the following reactions :

(b) Write simple chemical tests to distinguish between the following pairs of compounds
(i) Propanal and propanone (ii) Benzaldehyde and Benzoic acid (Comptt. Delhi 2017)

(a) Account for the following :
(i) Propanal is more reactive than propanone towards nucleophilic reagents.
(ii) Electrophilic substitution in benzoic acid takes place at meta position.
(iii) Carboxylic acids do not give characteristic reactions of carbonyl group.
(b) Give simple chemical test to distinguish between the following pairs of compounds:
(i) Acetophenone and benzaldehyde
(ii) Benzoic acid and ethylbenzoate. (Comptt. All India 2017)

(a) Write structures of A, B, C and D in the following reaction sequence :

(b) Arrange the following compounds in the increasing order of their boiling points :
CH₃CHO, CH₃CH₂OH, CH₃OCH₃, CH₃COOH. (Comptt. All India 2017)

Draw the structure of 2-methylbutanaI. (Comptt. Delhi 2016)

Write the structures of A, B, C, D and E in the following reactions : (Delhi 2016)

(a) Write the chemical equation for the reaction involved in Cannizzaro reaction.
(b) Draw the structure of the semicarbazone of ethanal.
(c) Why pKa of F—CH₂—COOH is lower than that of Cl—CH₂—COOH?
(d) Write the product in the following reaction:

(e) How can you distinguish between propanal and propanone? (Delhi 2016)

(a) Write the structures of A and B in the following reactions:

(b) Distinguish between:
(i) C₆H₅— COCH₃ and C₆H₅— CHO
(ii) CH₃COOH and HCOOH
(c) Arrange the following in the increasing order of their boiling points:
CH₃CHO, CH₃COOH, CH₃CH₂OH (All India 2016)

(a) Write the chemical reaction involved in Wolff-Kishner reduction.
(b) Arrange the following in the increasing order of their reactivity towards nucleophilic addition reaction:
C₆H₅COCH₃, CH₃— CHO, CH₃COCH₃
(c) Why carboxylic acid does not give reactions of carbonyl group?
(d) Write the product in the following reaction

(e) A and B are two functional isomers of compound C₃H₆O. On heating with NaOH and I₂, isomer B forms yellow precipitate of iodoform whereas isomer A does not form any precipitate. Write the formulae of A and B. (All India 2016)

(a) Write the product(s) in the following :

(b) Give simple tests to distinguish the following pairs of compounds :
(i) Ethanal and Propanal
(ii) Benzaldehyde and Acetophenone
(iii) Benzoic acid and Ethyl benzoate (Comptt. Delhi 2016)