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Haloalkanes and Haloarenes · Question 29

AIPMT 2009MCQEasy📈 Topic in 50% papers+4−1
1

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

Answer

(4) RX + KOH ROH + KX

Solution

(1) Wurtz reaction – coupling of two alkyl groups by sodium, not a substitution by a nucleophile.

(2) Reduction (hydrogenolysis) of the C–X bond.

(3) Formation of Grignard reagent – Mg is inserted between R and X.

(4) As per NCERT, the nucleophile OH- attacks the carbon of the C–X bond and the halide ion leaves:

R-X + OH- R-OH + X- nucleophilic substitution.

Answer: (4)

AIPMT 2009

Keep practising — Haloalkanes and Haloarenes

2

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

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

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
4

Which of the following undergoes nucleophilic substitution exclusively by SN1 mechanism?

  1. Ethyl chloride
  2. Isopropyl chloride
  3. Chlorobenzene
  4. Benzyl chloride
AIPMT 2005
5

Which of the following is least reactive in a nucleophilic substitution reaction?

  1. (CH3)3C-Cl
  2. CH2=CHCl
  3. CH3CH2Cl
  4. CH2=CHCH2Cl
AIPMT 2004
6

Chloropicrin is obtained by the reaction of

  1. steam on carbon tetrachloride
  2. nitric acid on chlorobenzene
  3. chlorine on picric acid
  4. nitric acid on chloroform
Out of syllabusAIPMT 2004
7

Reactivity order of halides for dehydrohalogenation is

  1. R-F > R-Cl > R-Br > R-I
  2. R-I > R-Br > R-Cl > R-F
  3. R-I > R-Cl > R-Br > R-F
  4. R-F > R-I > R-Br > R-Cl
AIPMT 2002
8

An organic compound A (C4H9Cl) on reaction with Na/diethyl ether gives a hydrocarbon which on monochlorination gives only one chloro derivative, then A is

  1. t-butyl chloride
  2. s-butyl chloride
  3. iso-butyl chloride
  4. n-butyl chloride
AIPMT 2001

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