Aldehydes, Ketones and Carboxylic Acids

Previous Years' CBSE Board Questions

8.1 Nomenclature and Structure of Carbonyl Group

VSA. (1 mark)

Write the structure of 2-methylbutanal. (1/5, Al 2015)

1. Draw the structure of 3-methylpentanal. (Delhi 2015C)
2. Write the IUPAC name of the following: CH3-CH2-CHO (AI 2015C)
3. Write the IUPAC name of the compound: CH₃-CH-CH₂-C-CH₃ OH

(Delhi 2014) (Ap)

1. Write the structure of 4-chloropentan-2-one.

(AI 2014)

1. Write the IUPAC name of the following compound: OH. (Foreign 2014) CHO

SAI (2 marks)

1. (d) Assertion (A) is false, but Reason (R) is true.

1. Draw the structures of the following:
2. p-Methylbenzaldehyde
3. 4-Methylpent-3-en-2-one (2/5, AI 2015C)

8.2 Preparation of Aldehydes and Ketones

VSA (1 mark)

1. What happens when benzene is treated with CH₃COCI in presence of anhydrous AICI₃?

(1/2, 2020) U

1. How can you convert the following: Benzene to acetophenone? (1/3, 2020)

Complete the following reaction : <math>(C_6H_5CH_2)_2Cd + 2CH_3COCI \longrightarrow</math> (1/3, Delhi 2019)

1. Write chemical equation for the following reaction: Benzoyl chloride is hydrogenated in presence of Pd/BaSO₄. (1/3, Delhi 2019, 1/5, 2018C)
2. Write the equation involved in the following reaction: Etard reaction. (1/2, Delhi 2017) R
3. Write the reaction involved in the following: Stephen reduction. (1/5, AI 2017)

1. Write the product in the following reaction: <math>CH_3 - CH = CH - CN \xrightarrow{\text{(a) DIBAL-H}} ?(1/5, AI 2017)</math> OR Write the product in the following reaction: <math>CH_3 - CH = CH - CH_2CN \xrightarrow{(i) DIBAL-H}</math> (ii) H2O (1/5, Delhi 2016)

1. How do you convert the following: Ethyne to ethanal (1/3, Foreign 2015) An

SAI (2 marks)

Write the major product(s) in the following:

(i) CH₃—CH=CH—CH₂—CN (i) DIBAL-H<br>(ii) H₂O+

(ii) <math>CH_3-CH_2-OH \xrightarrow{CrO_3}</math> (2/5, 2020)

Write the equations involved in the following

reactions:

1. (ii) Etard reaction (2/3, Foreign 2015)

8.4 Chemical Reactions

MCQ

1. Assertion: The final product in Aldol condensation is always <math>\alpha</math>, <math>\beta</math>-unsaturated carbonyl compound. Reason : α, β-unsaturated carbonyl compounds are stabilised due to conjugation.
2. Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A)
3. Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A)

(2023)

lodoform test is not given by

1. ethanol (b) ethanal
2. pentan-2-one (d) pentan-3-one (2020) Ap

1. Assertion (A): Reactivity of ketones is more than aldehydes. Reason (R): The carbonyl carbon of ketones is less electrophilic as compared to aldehydes.
2. Both Assertion (A) and Reason (R) are correct statements, and Reason (R) is the correct explanation of the Assertion (A).
3. Both Assertion (A) and Reason (R) are correct statements, but Reason (R) is not the correct explanation of the Assertion (A).
4. Assertion (A) is correct, but Reason (R) is incorrect statement.

Assertion (A) is incorrect, but Reason (R) is

correct statement. (2020)

1. Assertion (A): Oxidation of ketones is easier than aldehydes. Reason (R): C-C bond of ketones is stronger than C-H bond of aldehydes.
2. Both Assertion (A) and Reason (R) are correct statements, and Reason (R) is the correct explanation of the Assertion (A).
3. Both Assertion (A) and Reason (R) are correct statements, but Reason (R) is not the correct explanation of the Assertion (A).

Assertion (A) is correct, but Reason (R) is wrong

statement.

Assertion (A) is wrong, but Reason (R) is correct

statement. (2020) An

VSA (1 mark) OR

1. What happens when, propanone is treated with methyl magnesium iodide and then hydrolysed? (1/2, 2020)
2. How can you convert the following: Acetone to propene? (1/3, 2020) (An OR Do the following conversion in not more than two steps: Propanone to propene (1/3, Delhi 2017)
3. Write structures of compounds A and B in the following reaction:

OH <math>CrO_3 \searrow A \xrightarrow{H_2N-NH-CONH_2} B</math> (1/2, Delhi 2019)

1. Complete the following reaction: CHO NaCN/HCI 、 (1/3, Delhi 2019)

1. How do you convert the following: Ethanal to propanone (1/2, 2018)

Give simple chemical tests to distinguish between the following pair of compounds: Ethanal and propanal (1/5, 2018C)

<math>CH_3</math>

(ii) CH₃ - CHO conc. NaOH

CH₃ (2/5, Al 2019)

Give chemical tests to distinguish between the following pair of compounds: Benzaldehyde and acetophenone. (1/5, Al 2017C, 1/5, Delhi 2015C) OR Distinguish between the following: C₆H₅-COCH₃ and C₆H₅-CHO (1/2, Al 2016, 1/5, Al 2015)

Write the structures of A and B in the following reaction: CH3COCI H2, Pd - BaSO4 A H2N-OH B(1/5, AI 2016)

1. Give a simple chemical test to distinguish between the following pair of compounds: CH₃CH₂CHO and CH₃CH₂COCH₃

(1/2, Al 2016, 1/5, Al 2015) 40. Predict the products of the following reactions:

Give simple chemical tests to distinguish between the following pair of compounds: Propanal and butan-2-one (1/5, Foreign 2014)

1. Name the reagent used in the following reaction: CH3-CO-CH3 --> CH3-CH-CH3 OH (Delhi 2015, 1/2, Foreign 2015)

1. Give simple chemical tests to distinguish between the following pairs of compounds:
2. Benzaldehyde and benzoic acid
3. Propanal and propanone. (1/5, Delhi 2014) [An

Give simple chemical tests to distinguish between

the following pair of compounds:

Propanal and propanone (1/5, Al 2014)

33. Account for the following:

CH₃CHO is more reactive than CH₃COCH₃ towards

reaction with HCN. (Delhi 2014)

SAI (2 marks)

34. Write the products formed when benzaldehyde

reacts with the following reagents (Any two):

1. (iii) Tollens' reagent (Term II, 2021-22) R

Explain the following reactions:

(a) Wolff-Kishner reduction

(b) Cannizzaro reaction (Term II, 2021-22)

Write chemical equations for the following reactions: (i)

1. Write the structure of major product(s) in the following:
2. CH₃—CH₂—C—H (a) H₂N—NH₂ (b) KOH, glycol/heat
3. (a) Write the product in the following reaction: + HCN -----------------------------------
4. Give simple chemical test to distinguish between the following pair of compounds: Butanal and Butan-2-one (2/5, AI 2017)

Write the equations involved in the following

reactions: (i)

1. <math>CH_3-C=O</math> <math>(i) H_2N-NH_2</math> ? <math>CH_3</math> (ii) <math>KOH/Glycol, \Delta</math>?
2. C₆H₅—CO—CH₃ NaOH/I₂ ?+?(2/3, Delhi 2015)
3. A compound 'A' of molecular formula C2H3OCI undergoes a series of reactions as shown below. Write the structures of A, B, C and D in the following reactions: <math>(C_2H_3OCI)A \xrightarrow{H_2/Pd-BaSO_4} B \xrightarrow{dil. NaOH} C \xrightarrow{Heat} D</math> (Al 2015) (Ap

Describe the following reactions:

(ii)

1. Acetylation