PYQSide ExamsMy practice

Aldehydes, Ketones and Carboxylic Acids · Question 39

AIPMT 2015MCQMedium📈 Topic in 0% papers+4−1
1

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

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

Answer

(4) [figure]

Solution

Alkaline hydrolysis of an ester is a nucleophilic acyl substitution: OH- attacks the carbonyl carbon and the phenoxide ion is expelled.

⇒ The reaction is fastest when the carbonyl carbon is most electrophilic and the leaving phenoxide ion is most stable (i.e. the corresponding phenol is most acidic).

-NO2 at the para position is strongly electron-withdrawing (–I, –R); it stabilises the phenoxide ion by resonance and makes the acyl carbon more electrophilic.

∴ Order of ease of hydrolysis (para substituent): NO2 > Cl > H > OCH3

Answer: (4)

AIPMT 2015

Keep practising — Aldehydes, Ketones and Carboxylic Acids

2

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)
3

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)
4

Which one is most reactive towards nucleophilic addition reaction?

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
AIPMT 2014
5

Reaction by which benzaldehyde cannot be prepared

  1. [figure] + CO + HCl in presence of anhydrous AlCl3
  2. [figure] + Zn/Hg and conc. HCl
  3. [figure] + CrO2Cl2 in CS2 followed by H3O+
  4. [figure] + H2 in presence of Pd-BaSO4
NEET 2013
6

In the following reaction: HC CH [Hg2+]H2SO4 'P' Product 'P' will not give

  1. Tollen's reagent test
  2. Brady's reagent test
  3. Victor Meyer test
  4. Iodoform test
NEET 2013 (Karnataka)
7

Consider the reaction : RCHO + NH2NH2 RCH = N - NH2 What sort of reaction is it?

  1. Electrophilic addition-elimination reaction
  2. Free radical addition-elimination reaction
  3. Electrophilic substitution-elimination reaction
  4. Nucleophilic addition-elimination reaction
AIPMT 2012 (Mains)
8

Which of the following compounds will give a yellow precipitate with iodine and alkali?

  1. Acetophenone
  2. Methyl acetate
  3. Acetamide
  4. 2-Hydroxypropane
AIPMT 2012 (Mains)
9

Consider the following reaction [figure] The product A is

  1. C6H5CHO
  2. C6H5OH
  3. C6H5COCH3
  4. C6H5Cl
AIPMT 2012 (Mains)
10

In the following sequence of reactions CH3-Br KCNA H3O+B [ether]LiAlH4C the end product (C) is

  1. acetone
  2. methane
  3. acetaldehyde
  4. ethyl alcohol
AIPMT 2012 (Prelims)
11

CH3CHO and C6H5CH2CHO can be distinguished chemically by

  1. Benedict's test
  2. Iodoform test
  3. Tollens' reagent test
  4. Fehling's solution test
AIPMT 2012 (Prelims)

All Aldehydes, Ketones and Carboxylic Acids PYQs →

PDFDownload Aldehydes, Ketones and Carboxylic Acids PYQs as PDF Free, with answer key and a QR code to every solution — print it or study offline⬇
All NEET Chemistry chapters
Physical ChemistrySome Basic Concepts of ChemistryStructure of AtomStates of MatterThermodynamicsEquilibriumRedox ReactionsSolid StateSolutionsElectrochemistryChemical KineticsSurface Chemistry
Inorganic ChemistryClassification of Elements and Periodicity in PropertiesChemical Bonding and Molecular StructureHydrogens-Block Elementsp-Block Elements (Group 13 & 14)Environmental ChemistryGeneral Principles of Isolation of Elementsp-Block Elements (Group 15–18)d- and f-Block ElementsCoordination Compounds
Organic ChemistryOrganic Chemistry – Some Basic Principles and TechniquesIsomerismHydrocarbonsHaloalkanes and HaloarenesAlcohols, Phenols and EthersAldehydes, Ketones and Carboxylic AcidsAminesBiomoleculesPolymersChemistry in Everyday LifePrinciples Related to Practical Chemistry