PYQ Vault
EbooksTutor

Clemmensen and Wolff-Kishner reductions of C=O to CH2

This type of question, asked 12 times: May 2021 S1, 2 May 2023 S2, 9 May 2023 S2, 16 May 2023 S2, 9 May 2024 S1, 13 May 2024 S2, 14 May 2024 S1, 14 May 2024 S2, 25 Apr 2025 S1, 20 Apr 2026 S2, 12 May 2026 S1, 19 May 2026 S1. All 13 questions below, oldest first.

Try each one first, then open its answer.

  1. Question 1

    May 2021 S1

    89
    Identify the reaction in which the carbonyl group of aldehydes and ketones is reduced to a methylene group on treatment with zinc-amalgam and conc. HCl.

    Tap an option to check your answer.

  2. Question 2

    2 May 2023 S2

    85
    Identify the product B in the following reaction. Ethyl phenyl ketone →H2N-NH2\xrightarrow{\text{H}_2\text{N-NH}_2} A →ΔKOH, HO(CH2)2OH\xrightarrow[\Delta]{\text{KOH},\ \text{HO(CH}_2)_2\text{OH}} B

    Tap an option to check your answer.

  3. Question 3

    9 May 2023 S2

    64
    What type of following compounds is obtained in first step of Wolf-Kishner reduction of carbonyl compounds?

    Tap an option to check your answer.

  4. Question 4

    16 May 2023 S2

    78
    Identify name of reaction when aldehyde or ketone react with Zn-Hg/conc. HCl to give alkane.

    Tap an option to check your answer.

  5. Question 5

    9 May 2024 S1

    88
    Identify the product 'B' in following reaction. Ethyl phenyl ketone →H2N−NH2\xrightarrow{H_2N-NH_2} A →KOH,(HO−CH2)2,Δ\xrightarrow{KOH, (HO-CH_2)_2, \Delta} B

    Tap an option to check your answer.

  6. Question 6

    13 May 2024 S2

    78
    Which of the following is Wolf-Kishner reduction?

    Tap an option to check your answer.

  7. Question 7

    14 May 2024 S1

    91
    Identify the reaction in which carbonyl group of aldehydes and ketones is reduced to methylene group on treatment with hydrazine followed by heating with sodium hydroxide in ethylene glycol.

    Tap an option to check your answer.

  8. Question 8

    14 May 2024 S2

    60
    Which of the following is Clemmensen reduction?

    Tap an option to check your answer.

  9. Question 9

    25 Apr 2025 S1

    78
    Identify the name of reaction if carbonyl group of aldehydes and ketones is reduced to methylene group on treatment with hydrazine followed by heating with sodium hydroxide in ethylene glycol.

    Tap an option to check your answer.

  10. Question 10

    20 Apr 2026 S2

    42
    Which of the following reactions is preferentially used to prepare the corresponding paraffins from alkanone?

    Tap an option to check your answer.

  11. Question 11

    12 May 2026 S1

    40
    C=O+4[H]→ΔZn−Hg, conc. HCl−CH2+H2O\mathrm{C = O + 4[H] \xrightarrow[\Delta]{Zn{-}Hg,\ conc.\ HCl} {-}CH_2 + H_2O} (Carbonyl group in aldehydes and ketones) (Methylene group) Identify the name of above reaction.

    Tap an option to check your answer.

  12. Question 12

    19 May 2026 S1

    18
    Which reaction is used to synthesize straight-chain alkylbenzenes?

    Tap an option to check your answer.

  13. Question 13

    19 May 2026 S1

    16
    Which of the following compounds is obtained in the first step of Wolf - Kishner reduction when alkyl aryl ketones are reduced to alkyl benzene?

    Tap an option to check your answer.