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Aldehydes, Ketones and Carboxylic Acids · Question 32

NEET 2017MCQEasy📈 Topic in 25% papers+4−1
1

Of the following, which is the product formed when cyclohexanone undergoes aldol condensation followed by heating?

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]

Answer

(1) [figure]

Solution

Cyclohexanone has α-hydrogens, so with dilute alkali one molecule (as its carbanion) adds to the C=O group of another molecule to give a β-hydroxy ketone (aldol):

[figure]

On heating, the aldol loses a water molecule to give the α,β-unsaturated ketone (aldol condensation product):

[figure]

∴ The product is 2-cyclohexylidenecyclohexan-1-one.

Answer: (1)

NEET 2017

Keep practising — Aldehydes, Ketones and Carboxylic Acids

2

Consider the reactions, [figure] Identify A, X, Y and Z.

  1. A-Methoxymethane, X-Ethanol, Y-Ethanoic acid, Z-Semicarbazide.
  2. A-Ethanal, X-Ethanol, Y-But-2-enal, Z-Semicarbazone.
  3. A-Ethanol, X-Acetaldehyde, Y-Butanone, Z-Hydrazone.
  4. A-Methoxymethane, X-Ethanoic acid, Y-Acetate ion, Z-Hydrazine.
NEET 2017
3

Which of the following reagents would distinguish cis-cyclopentane-1,2-diol from the trans-isomer?

  1. MnO2
  2. Aluminium isopropoxide
  3. Acetone
  4. Ozone
NEET 2016 (Phase 1)
4

The product formed by the reaction of an aldehyde with a primary amine is

  1. carboxylic acid
  2. aromatic acid
  3. Schiff's base
  4. ketone
NEET 2016 (Phase 1)
5

The correct order of the strengths of the carboxylic acids [figure] is

  1. I > II > III
  2. II > III > I
  3. III > II > I
  4. II > I > III
NEET 2016 (Phase 2)
6

The correct structure of the product 'A' formed in the reaction [figure]

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
NEET 2016 (Phase 2)
7

Reaction of a carbonyl compound with one of the following reagents involves nucleophilic addition followed by elimination of water. The reagent is

  1. hydrazine in presence of feebly acidic solution
  2. hydrocyanic acid
  3. sodium hydrogen sulphate
  4. a Grignard reagent.
AIPMT 2015
8

Which one of the following esters gets hydrolysed most easily under alkaline conditions?

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
AIPMT 2015
9

Treatment of cyclopentanone [figure] with methyl lithium gives which of the following species ?

  1. Cyclopentanonyl radical
  2. Cyclopentanonyl biradical
  3. Cyclopentanonyl anion
  4. Cyclopentanonyl cation
AIPMT 2015 (Cancelled)
10

An organic compound 'X' having molecular formula C5H10O yields phenylhydrazone and gives negative response to the iodoform test and Tollens' test. It produces n-pentane on reduction. 'X' could be

  1. 3-pentanone
  2. n-amyl alcohol
  3. pentanal
  4. 2-pentanone
AIPMT 2015 (Cancelled)
11

Which one is most reactive towards nucleophilic addition reaction?

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
AIPMT 2014

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