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Hydrocarbons · Question 24

NEET 2016 (Phase 1)MCQMedium📈 Topic in 12% papers+4−1
1

Consider the nitration of benzene using mixed conc. H2SO4 and HNO3. If a large amount of KHSO4 is added to the mixture, the rate of nitration will be

  1. unchanged
  2. doubled
  3. faster
  4. slower

Answer

(4) slower

Solution

Electrophile formation in nitration:

HNO3 + 2H2SO4 NO2+ + H3O+ + 2HSO4-

∵ KHSO4 supplies a large amount of the common ion HSO4- ⇒ equilibrium shifts backward (Le Chatelier's principle).

⇒ Concentration of the nitronium ion NO2+ decreases.

∴ The rate of nitration becomes slower.

Answer: (4)

NEET 2016 (Phase 1)

Keep practising — Hydrocarbons

2

In the reaction H-C CH [(ii) CH3CH2Br](i) NaNH2/liq. NH3 X [(ii) CH3CH2Br](i) NaNH2/liq. NH3 Y, X and Y are

  1. X = 2-Butyne, Y = 2-Hexyne
  2. X = 1-Butyne, Y = 2-Hexyne
  3. X = 1-Butyne, Y = 3-Hexyne
  4. X = 2-Butyne, Y = 3-Hexyne
NEET 2016 (Phase 1)
3

Which of the following can be used as halide component for Friedel-Crafts reaction?

  1. Chlorobenzene
  2. Bromobenzene
  3. Chloroethene
  4. Isopropyl chloride
NEET 2016 (Phase 2)
4

Which of the following compounds shall not produce propene by reaction with HBr followed by elimination or direct only elimination reaction ?

  1. [figure]
  2. H3C- H2 |C-CH2OH
  3. H2C=C=O
  4. H3C- H2 |C-CH2Br
NEET 2016 (Phase 2)
5

In the given reaction, [figure] the product P is

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
NEET 2016 (Phase 2)
6

The compound that will react most readily with gaseous bromine has the formula

  1. C3H6
  2. C2H2
  3. C4H10
  4. C2H4
NEET 2016 (Phase 2)
7

In the reaction with HCl, an alkene reacts in accordance with the Markovnikov's rule to give a product 1-chloro-1-methylcyclohexane. The possible alkene is

  1. [figure] (A)
  2. [figure] (B)
  3. (A) and (B)
  4. [figure]
AIPMT 2015
8

2,3-Dimethyl-2-butene can be prepared by heating which of the following compounds with a strong acid?

  1. (CH3)3CCH=CH2
  2. (CH3)2C=CHCH2CH3
  3. (CH3)2CHCH2CH=CH2
  4. (CH3)2CH- CH3 |CH-CH=CH2
AIPMT 2015
9

The oxidation of benzene by V2O5 in the presence of air produces

  1. maleic anhydride
  2. benzoic acid
  3. benzaldehyde
  4. benzoic anhydride.
AIPMT 2015
10

A single compound of the structure, [figure] is obtainable from ozonolysis of which of the following cyclic compounds?

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
AIPMT 2015 (Cancelled)
11

The reaction of C6H5CH=CHCH3 with HBr produces

  1. C6H5CH2CH2CH2Br
  2. [figure]
  3. C6H5 Br |CHCH2CH3
  4. C6H5CH2 Br |CHCH3
AIPMT 2015 (Cancelled)

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