PYQSide ExamsMy practice

Haloalkanes and Haloarenes · Question 21

AIPMT 2012 (Mains)MCQMedium📈 Topic in 12% papers+4−1
1

In the replacement reaction [figure] The reaction will be most favourable if M happens to be

  1. Na
  2. K
  3. Rb
  4. Li

Answer

(3) Rb

Solution

The reaction is a halogen exchange (alkyl chloride → alkyl fluoride) by a metal fluoride MF.

It is most favourable when the fluoride ion is most easily available, i.e. when the M–F bond is most ionic and the lattice enthalpy of MF is lowest.

∵ Lattice enthalpy of alkali metal fluorides decreases as the size of the cation increases: LiF > NaF > KF > RbF

⇒ RbF is the most ionic and gives free F- most easily.

∴ The reaction is most favourable when M is Rb.

Answer: (3)

AIPMT 2012 (Mains)

Keep practising — Haloalkanes and Haloarenes

2

Which of the following compounds undergoes nucleophilic substitution reaction most easily?

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
AIPMT 2011 (Mains)
3

Consider the reactions. (i) (CH3)2CH-CH2Br C2H5OH (CH3)2CH-CH2OC2H5 + HBr (ii) (CH3)2CH-CH2Br C2H5O- (CH3)2CH-CH2OC2H5 + Br- The mechanisms of reactions (i) and (ii) are respectively

  1. SN1 and SN2
  2. SN1 and SN1
  3. SN2 and SN2
  4. SN2 and SN1
AIPMT 2011 (Mains)
4

Which one is a nucleophilic substitution reaction among the following ?

  1. CH3-CH=CH2 + H2O H+ CH3- OH |CH-CH3
  2. RCHO + R'MgX R- OH |CH-R'
  3. CH3-CH2- CH3 |CH-CH2Br + NH3 CH3-CH2- CH3 |CH-CH2NH2
  4. CH3CHO + HCN CH3CH(OH)CN
AIPMT 2011 (Prelims)
5

In the following reaction C6H5CH2Br [2. H3O+]1. Mg, ether X, the product 'X' is

  1. C6H5CH2OCH2C6H5
  2. C6H5CH2OH
  3. C6H5CH3
  4. C6H5CH2CH2C6H5
AIPMT 2010 (Mains)
6

The reaction of toluene with Cl2 in presence of FeCl3 gives X and reaction in presence of light gives Y. Thus, X and Y are

  1. X = Benzal chloride, Y = o-chlorotoluene
  2. X = m-chlorotoluene, Y = p-chlorotoluene
  3. X = o- and p-chlorotoluene, Y = Trichloromethyl benzene
  4. X = Benzyl chloride, Y = m-chlorotoluene
AIPMT 2010 (Prelims)
7

Which one is most reactive towards SN1 reaction?

  1. C6H5CH(C6H5)Br
  2. C6H5CH(CH3)Br
  3. C6H5C(CH3)(C6H5)Br
  4. C6H5CH2Br
AIPMT 2010 (Prelims)
8

The correct order of increasing reactivity of [figure] C–X bond towards nucleophile in the following compounds is

  1. I < II < IV < III
  2. II < III < I < IV
  3. IV < III < I < II
  4. III < II < I < IV
AIPMT 2010 (Prelims)
9

Which of the following reactions is an example of nucleophilic substitution reaction?

  1. 2RX + 2Na R-R + 2NaX
  2. RX + H2 RH + HX
  3. RX + Mg RMgX
  4. RX + KOH ROH + KX
AIPMT 2009
10

Trichloroacetaldehyde, CCl3CHO reacts with chlorobenzene in presence of sulphuric acid and produces

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
AIPMT 2009
11

In an SN2 substitution reaction of the type R-Br + Cl- DMF R-Cl + Br- which one of the following has the highest relative rate?

  1. CH3- CH3 | CH3 |C-CH2Br
  2. CH3CH2Br
  3. CH3CH2CH2Br
  4. CH3- CH3 |CH-CH2Br
AIPMT 2008

All Haloalkanes and Haloarenes PYQs →

PDFDownload Haloalkanes and Haloarenes 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