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Hydrocarbons · Question 29

NEET 2016 (Phase 2)MCQMedium📈 Topic in 62% papers+4−1
1

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

  1. C3H6
  2. C2H2
  3. C4H10
  4. C2H4

Answer

(1) C3H6

Solution

C4H10 (alkane) reacts with Br2 only by slow free-radical substitution.

Alkenes add Br2 (electrophilic addition) faster than alkynes, because the π electrons of C≡C are held more tightly by the more electronegative sp carbons.

Among alkenes, propene CH3-CH=CH2 has an electron-releasing CH3 group (+I effect and hyperconjugation) ⇒ richer π electron cloud than ethene ⇒ reacts fastest.

∴ C3H6.

Answer: (1)

NEET 2016 (Phase 2)

Keep practising — Hydrocarbons

2

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
3

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
4

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
5

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)
6

The reaction of C6H5CH=CHCH3 with HBr produces

  1. C6H5CH2CH2CH2Br
  2. [figure]
  3. C6H5 Br |CHCH2CH3
  4. C6H5CH2 Br |CHCH3
AIPMT 2015 (Cancelled)
7

What products are formed when the following compound is treated with Br2 in the presence of FeBr3? [figure]

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
AIPMT 2014
8

Some meta-directing substituents in aromatic substitution are given. Which one is most deactivating ?

  1. -COOH
  2. -NO2
  3. -C N
  4. -SO3H
NEET 2013
9

Which of the following compounds will not undergo Friedel-Crafts reaction easily?

  1. Nitrobenzene
  2. Toluene
  3. Cumene
  4. Xylene
NEET 2013
10

Nitrobenzene on reaction with conc. HNO3/H2SO4 at 80-100 C forms which one of the following products?

  1. 1, 4-Dinitrobenzene
  2. 1, 2, 4 - Trinitrobenzene
  3. 1, 2-Dinitrobenzene
  4. 1, 3-Dinitrobenzene
NEET 2013
11

Which of the following reagents will be able to distinguish between 1-butyne and 2-butyne?

  1. NaNH2
  2. HCl
  3. O2
  4. Br2
AIPMT 2012 (Mains)

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