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Haloalkanes and Haloarenes · Question 15

NEET (UG) 2021MCQEasy📈 Topic in 0% papers+4−1
1

The correct sequence of bond enthalpy of 'C-X' bond is :

  1. CH3-Cl > CH3-F > CH3-Br > CH3-I
  2. CH3-F < CH3-Cl < CH3-Br < CH3-I
  3. CH3-F > CH3-Cl > CH3-Br > CH3-I
  4. CH3-F < CH3-Cl > CH3-Br > CH3-I

Answer

(3) CH3-F > CH3-Cl > CH3-Br > CH3-I

Solution

As per NCERT, the C–X bond length increases from F to I (size of halogen increases) ⇒ bond enthalpy decreases.

Bond enthalpies ( kJ mol-1): CH3-F 452, CH3-Cl 351, CH3-Br 293, CH3-I 234

∴ CH3-F > CH3-Cl > CH3-Br > CH3-I

Answer: (3)

NEET (UG) 2021

Keep practising — Haloalkanes and Haloarenes

2

Elimination reaction of 2-Bromopentane to form pent-2-ene is :

  1. A, C and D only
  2. B, C and D only
  3. A, B and D only
  4. A, B and C only
NEET (UG) 2020
3

The compound C7H8 undergoes the following reactions : C7H8 3Cl2/ A Br2/Fe B Zn/HCl C The product 'C' is

  1. m-bromotoluene
  2. o-bromotoluene
  3. 3-bromo-2,4,6-trichlorotoluene
  4. p-bromotoluene
NEET 2018
4

Identify A and predict the type of reaction. [figure]

  1. [figure] and elimination addition reaction
  2. [figure] and cine substitution reaction
  3. [figure] and cine substitution
  4. [figure] and substitution reaction
NEET 2017
5

Consider the reaction, CH3CH2CH2Br + NaCN CH3CH2CH2CN + NaBr The reaction will be the fastest in

  1. ethanol
  2. methanol
  3. N,N-dimethylformamide (DMF)
  4. water
NEET 2016 (Phase 2)
6

Which of the following reaction(s) can be used for the preparation of alkyl halides? (I) CH3CH2OH + HCl Anh. ZnCl2 (II) CH3CH2OH + HCl Anh. ZnCl2 (III) (CH3)3COH + HCl Anh. ZnCl2 (IV) (CH3)2CHOH + HCl Anh. ZnCl2

  1. (I) and (II) only
  2. (IV) only
  3. (III) and (IV) only
  4. (I), (III) and (IV) only
AIPMT 2015
7

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

  1. Na
  2. K
  3. Rb
  4. Li
AIPMT 2012 (Mains)
8

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

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
AIPMT 2011 (Mains)
9

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)
10

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)
11

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)

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