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Hydrocarbons · Question 16

NEET (UG) 2021MCQEasy📈 Topic in 12% papers+4−1
1

CH3CH2COO-Na+ [Heat]NaOH, +? CH3CH3 + Na2CO3 Consider the above reaction and identify the missing reagent/chemical.

  1. DIBAL-H
  2. B2H6
  3. Red Phosphorus
  4. CaO

Answer

(4) CaO

Solution

As per NCERT, sodium salts of carboxylic acids on heating with soda lime (a mixture of NaOH and CaO) lose carbon dioxide (decarboxylation) and give an alkane with one carbon less.

CH3CH2COONa + NaOH [ ]CaO CH3CH3 + Na2CO3

∴ the missing chemical is CaO.

Answer: (4)

NEET (UG) 2021

Keep practising — Hydrocarbons

2

Which of the following alkane cannot be made in good yield by Wurtz reaction?

  1. 2, 3-Dimethylbutane
  2. n-Heptane
  3. n-Butane
  4. n-Hexane
NEET (UG) 2020
3

An alkene on ozonolysis gives methanal as one of the products, Its structure is :

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
NEET (UG) 2020
4

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

  1. [figure]
  2. [figure]
  3. [figure]
  4. [figure]
NEET (UG) 2019
5

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
NEET (UG) 2019
6

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
NEET (UG) 2019
7

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
NEET 2018
8

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
NEET 2017
9

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
NEET 2016 (Phase 1)
10

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)
11

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)

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