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Aldehydes, Ketones and Carboxylic Acids

JEE Main 2024 (Online) 30th January Morning ShiftMCQEasy📈 Topic in 17% papers+4−1
Ques. 1JEE Main 2024, 30 January (Morning Shift)

In the given reactions, identify the reagent A and reagent B. [figure]

  1. A - CrO3 B - CrO3
  2. A - CrO3 B - CrO2Cl2
  3. A - CrO2Cl2 B - CrO3
  4. A - CrO2Cl2 B - CrO2Cl2

Answer

(2) A - CrO3 B - CrO2Cl2

Solution

Route A — chromic oxide in acetic anhydride (benzylidene diacetate, then hydrolysis):

C6H5CH3 [273-283 K]CrO3, (CH3CO)2O C6H5CH(OCOCH3)2

H3O+, C6H5CHO

Route B — chromyl chloride in CS2 (Étard reaction, chromium complex, then hydrolysis):

C6H5CH3 CrO2Cl2, CS2 C6H5CH(OCrOHCl2)2

H3O+ C6H5CHO

∴ A = CrO3, B = CrO2Cl2

Answer: (2)

Keep practising — Aldehydes, Ketones and Carboxylic Acids

Ques. 2JEE Main 2024, 30 January (Morning Shift)

The compound formed by the reaction of ethanal with semicarbazide contains number of nitrogen atoms.

Ques. 3JEE Main 2024, 30 January (Evening Shift)

m-chlorobenzaldehyde on treatment with 50% KOH solution yields :

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
Ques. 4JEE Main 2024, 29 January (Morning Shift)

The final product A formed in the following multistep reaction sequence is [figure]

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
Ques. 5JEE Main 2024, 29 January (Morning Shift)

From the compounds given below, number of compounds which give positive Fehling's test is . Benzaldehyde, Acetaldehyde, Acetone, Acetophenone, Methanal, 4-nitrobenzaldehyde, cyclohexane carbaldehyde.

Ques. 6JEE Main 2024, 29 January (Evening Shift)

Identify the reagents used for the following conversion [figure]

  1. A = LiAlH4, B = NaOH(aq), C = NH2-NH2/KOH, ethylene glycol
  2. A = DIBAL-H, B = NaOH(aq), C = NH2-NH2/KOH, ethylene glycol
  3. A = LiAlH4, B = NaOH(alc), C = Zn/HCl
  4. A = DIBAL-H, B = NaOH(alc), C = Zn/HCl
Ques. 7JEE Main 2024 (Online)

Match List-I with List-II and choose the correct option.

  1. A-II, B-IV, C-I, D-III
  2. A-I, B-II, C-III, D-IV
  3. A-IV, B-III, C-II, D-I
  4. A-II, B-I, C-IV, D-III

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