JEE Main Previous Year Questions With Solutions on Hydrocarbons

1. The gas liberated by the electrolysis of Dipotassium succinate solution is :

(1) Ethyne

(2) Ethene

(3) Propene

(4) Ethane

Solution:

The correct option for the given question is (2).

2. Which one of the following classes of compounds is obtained by polymerization of acetylene?

(1) Poly-ene

(2) Poly-yne

(3) Poly-amide

(4) Poly-ester

Solution:

The correct option for the given question is (2).

3. One mole of a symmetrical alkene on ozonolysis gives two moles of an aldehyde having a molecular mass of 44 u. The alkene is:-

(1) Ethene

(2) Propene

(3) 1-Butene

(4) 2-Butene

Solution:

The correct option for the given question is (4).

4. Which branched chain isomer of the hydrocarbon with molecular mass 72 u gives only one isomer of mono substituted alkyl halide?

(1) Neopentane

(2) Isohexane

(3) Neohexane

(4) Tertiary butyl chloride

Solution:

The correct option for the given question is (1).

5. Ozonolysis of an organic compound gives formaldehyde as one of the products. This confirms the presence of:-

(1) an isopropyl group

(2) an acetylenic triple bond

(3) two ethylenic double bonds

(4) a vinyl group

Solution:

The correct option for the given question is (3).

6. In the given transformation, which of the following is the most appropriate reagent?

(1) NaBH₄

(2) NH₂-NH₂, OH

(3) Zn – Hg / HCl

(4) Na, Liq.NH₃

Solution:

The correct option for the given question is (2).

7. The number and type of bonds in C₂^2- ion in CaC₂ are:

(1) Two σ bonds and one π – bond

(2) Two σ bonds and two π – bonds

(3) One σ bond and two π – bonds

(4) One σ bond and one π bond

Solution:

The correct option for the given question is (3).

8. In the hydroboration – oxidation reaction of propene with diborane, H₂O₂ and NaOH, the organic compound formed is :

(1) CH₃CH₂CH₂OH

( 2) (CH₃)₃COH

(3) CH₃CHOHCH₃

(4) CH₃CH₂OH

Solution:

The correct option for the given question is (1).

9. Which one of the following has the minimum boiling point?

(1) n-Butane

(2) 1-Butyne

(3) 1-Butene

(4) Isobutene

Solution:

The correct option for the given question is (4).

10. The gas evolved on heating CH₃MgBr in methanol is

(1) methane

(2) ethane

(3) propane

(4) HBr

Solution:

The correct option for the given question is (1).

11. The reagent needed for converting

is

(1) H₂ / lindlar Cat.

(2) Catalytic Hydrogenation

(3) LiAlH₄

(4) Li/ NH₃

Solution:

The correct option for the given question is (4).

12. In the presence of peroxide, HCl and HI do not give anti-Markovnikov’s addition to alkenes because

(1) All the steps are exothermic in HCl and HI

(2) One of the steps is endothermic in HCl and HI

(3) HCl is oxidizing and the HI is reducing

(4) Both HCl and HI are strong acids

Solution:

The correct option for the given question is (2).

13. Polysubstitution is a major drawback in

(a) Reimer-Tiemann reaction

(b) Friedel-Crafts acylation

(c) Friedel-Crafts alkylation

(d) Acetylation of aniline.

Solution:

The correct option for the given question is (3).

14. Which one of the following is reduced with zinc and hydrochloric acid to give the corresponding hydrocarbon?

(1) Ethyl acetate

(2) Acetic acid

(3) Acetamide

(4) Butan-2-one

Solution:

The correct option for the given question is (4).

15. The hydrocarbon which can react with sodium in liquid ammonia is

(1) CH₃CH₂C ≡ CCH₂CH₃

(2) CH₃CH₂CH₂C ≡ CCH₂CH₂CH₃

(3) CH₃CH₂C ≡ CH

(4) CH₃CH ≡ CHCH₃

Solution:

The correct option for the given question is (3).