Atomos Test Generator Free PYQs ExamsMy practice Log in / Sign up free

Hydrocarbons

NEET (UG) 2019MCQEasy📈 Topic in 12% papers+4−1
Ques. 1NEET (UG) 2019

Among the following, the reaction that proceeds through an electrophilic substitution, is :

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

Answer

(4) [figure]

Solution

(1) Benzene + Cl2 in UV light gives benzene hexachloride (BHC) by free radical addition.

(2) Benzyl alcohol + HCl gives benzyl chloride by nucleophilic substitution (Cl- replaces –OH).

(3) C6H5N2+Cl- with Cu2Cl2 (Sandmeyer reaction): N2 is replaced by Cl, not an electrophilic substitution.

(4) As per NCERT, in halogenation of benzene the Lewis acid gives the electrophile:

Cl2 + AlCl3 Cl+ + [AlCl4]-

Cl+ attacks the ring and H+ is lost ⇒ chlorobenzene + HCl ⇒ electrophilic substitution.

Answer: (4)

Keep practising — Hydrocarbons

Ques. 2NEET (UG) 2019

The most suitable reagent for the following conversion, is : [figure]

  1. Zn / HCl
  2. Hg2+/H+, H2O
  3. Na / liquid NH3
  4. H2, Pd/C, quinoline
Ques. 3NEET (UG) 2019

An alkene “A” on reaction with O3 and Zn + H2O gives propanone and ethanal in equimolar ratio. Addition of HCl to alkene “A” gives “B” as the major product. The structure of product “B” is :

  1. H3C-CH2- Cl | CH3 |C-CH3
  2. H3C- Cl |CH- CH3 | CH3 |CH
  3. Cl-CH2-CH2- CH3 | CH3 |CH
  4. H3C-CH2- CH2Cl |CH-CH3
Ques. 4NEET 2018

Hydrocarbon (A) reacts with bromine by substitution to form an alkyl bromide which by Wurtz reaction is converted to gaseous hydrocarbon containing less than four carbon atoms. (A) is

  1. CH CH
  2. CH2 = CH2
  3. CH3 - CH3
  4. CH4
Ques. 5NEET 2017

Predict the correct intermediate and product in the following reaction : H3C-C CH [HgSO4]H2O, H2SO4 (A)Intermediate (B)Product

  1. A : H3C- OH |C=CH2 B : H3C- SO4 |C=CH2
  2. A : H3C- O \|C-CH3 B : H3C-C CH
  3. A : H3C- OH |C=CH2 B : H3C- O \|C-CH3
  4. A : H3C- SO4 |C=CH2 B : H3C- O \|C-CH3
Ques. 6NEET 2016 (Phase 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
Ques. 7NEET 2016 (Phase 1)

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
Ques. 8NEET 2016 (Phase 2)

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

  1. Chlorobenzene
  2. Bromobenzene
  3. Chloroethene
  4. Isopropyl chloride
Ques. 9NEET 2016 (Phase 2)

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
Ques. 10NEET 2016 (Phase 2)

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

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
Ques. 11NEET 2016 (Phase 2)

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

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

All Hydrocarbons PYQs →

PDFDownload Hydrocarbons PYQs as PDF Free, with answer key and a QR code to every solution — print it or study offline⬇
All NEET Chemistry chapters