JEE Main > Hydrocarbons

Explore popular questions from Hydrocarbons for JEE Main. This collection covers Hydrocarbons previous year JEE Main questions hand picked by popular teachers.


Q 1.    

Correct4

Incorrect-1

Which of these will not react with acetylene?

{tex} \mathrm { NaOH } {/tex}

B

{tex}\mathrm{Ammonical\,}\mathrm{AgNO_3}{/tex}

C

{tex} \mathrm { Na } {/tex}

D

{tex} \mathrm { HCl } {/tex}

Explanation





Q 2.    

Correct4

Incorrect-1

What is the product when acetylene reacts with hypochlorous acid?

A

{tex} \mathrm { CH } _ { 3 } \mathrm { COCl } {/tex}

B

{tex} \mathrm { ClCH } _ { 2 } \mathrm { CHO } {/tex}

{tex} \mathrm { Cl } _ { 2 } \mathrm { CHCHO } {/tex}

D

{tex}\mathrm{ClCHCOOH}{/tex}

Explanation



Q 3.    

Correct4

Incorrect-1

On mixing a certain alkane with chlorine and irradiating it with ultraviolet light, it forms only one monochloroalkane. This alkane could be

A

pentane

B

isopentane

neopentane

D

propane

Explanation

Q 4.    

Correct4

Incorrect-1

2-Methylbutane on reacting with bromine in the presence of sunlight gives mainly

A

{tex} 1 {/tex} - bromo- {tex} 3 {/tex} -methylbutane

B

{tex} 2 {/tex} -bromo- {tex} 3 {/tex} -methylbutane

{tex} 2 {/tex} -bromo- {tex} 2 {/tex} -methylbutane

D

{tex} 1 {/tex} - bromo- {tex} 2 {/tex} -methylbutane

Explanation



Q 5.    

Correct4

Incorrect-1

Butene- 1 may be converted to butane by reaction with

A

{tex} \mathrm { Sn } - \mathrm { HCl } {/tex}

B

{tex} \mathrm { Zn } - \mathrm { Hg } {/tex}

{tex} \mathrm { Pd } / \mathrm { H } _ { 2 } {/tex}

D

{tex} \mathrm { Zn } - \mathrm { HCl } {/tex}

Explanation

Q 6.    

Correct4

Incorrect-1

Reaction of one molecule of HBr with one molecule of {tex} 1,3 - {/tex} butadiene at {tex} 40 ^ { \circ } \mathrm { C } {/tex} gives predominantly

A

1-bromo-2-butene under kinetically controlled conditions

B

3-bromobutene under thermodynamically controlled conditions

1 -bromo- 2 -butene under thermodynamically controlled conditions

D

3 -bromobutene under kinetically controlled conditions

Explanation

Q 7.    

Correct4

Incorrect-1

Of the five isomeric hexanes, the isomer which can give two monochlorinated compounds is

A

{tex} 2 {/tex} -methylpentane

B

{tex} 2,2 {/tex} -dimethylbutane

{tex} 2,3 {/tex} -dimethylbutane

D

n-hexane

Explanation




Q 8.    

Correct4

Incorrect-1

Acid catalyzed hydration of alkenes except ethene leads to the formation of

mixture of secondary and tertiary alcohols

B

mixture of primary and secondary alcohols

C

secondary or tertiary alcohol

D

primary alcohol

Explanation


Q 9.    

Correct4

Incorrect-1

Which types of isomerism is shown by {tex} 2,3 {/tex} -dichlorobutane?

A

Structural

B

Geometric

Optical

D

Diastereo

Explanation



Q 10.    

Correct4

Incorrect-1

The compound formed as a result of oxidation of ethyl benzene by {tex}KMnO_4{/tex} is

A

benzyl alcohol

B

benzophenone

C

acetophenone

benzoic acid.

Explanation



Q 11.    

Correct4

Incorrect-1

Which of the following reactions will yield {tex} 2,2 - {/tex} dibromopropane?

A

{tex} \mathrm { CH } _ { 3 } - \mathrm { CH } = \mathrm { CH } _ { 2 } + \mathrm { HBr } \rightarrow {/tex}

{tex} \mathrm { CH } _ { 3 } - \mathrm { C } \equiv \mathrm { CH } + 2 \mathrm { HBr } \rightarrow {/tex}

C

{tex} \mathrm { CH } _ { 3 } \mathrm { CH } = \mathrm { CHBr } + \mathrm { HBr } \rightarrow {/tex}

D

{tex} \mathrm { CH } \equiv \mathrm { CH } + 2 \mathrm { HBr } \rightarrow {/tex}

Explanation



Q 12.    

Correct4

Incorrect-1

The reaction of toluene with {tex} \mathrm { Cl } _ { 2 } {/tex} in presence of {tex} \mathrm { FeCl } _ { 3 } {/tex} gives predominantly

A

{tex} \mathrm { m } {/tex} -chlorobenzene

B

benzoyl chloride

C

benzyl chloride

{tex} o - {/tex} and {tex} \mathrm { p } {/tex} -chlorotoluene

Explanation



Q 13.    

Correct4

Incorrect-1

Toluene is nitrated and the resulting product is reduced with tin and hydrochloric acid. The product so obtained is diazotised and then heated wth cuprous bromide. The reaction mixture so formed contans

mixture of {tex} o - {/tex} and {tex} p {/tex} -bromotoluenes

B

mixture of {tex} o - {/tex} and {tex} p {/tex} - dibromobenzenes

C

mixture of {tex} o - {/tex} and {tex} p {/tex} -bromoanilines

D

mixture of {tex} o - {/tex} and {tex} m {/tex} -bromotoluenes

Explanation









Q 14.    

Correct4

Incorrect-1

In the following sequence of reactions, the alkene affords the compound 'B'
{tex} \mathrm { CH } _ { 3 } - \mathrm { CH } = \mathrm { CH } - \mathrm { CH } _ { 3 } \stackrel { \mathrm { O } _ { 3 } } { \longrightarrow } \mathrm { A } \frac { \mathrm { H } _ { 2 } \mathrm { O } } { \mathrm { Zn } } \rightarrow \mathrm { B } {/tex}
The compound {tex} \mathrm { B } {/tex} is

A

{tex} \mathrm { CH } _ { 3 } \mathrm { CH } _ { 2 } \mathrm { CHO } {/tex}

B

{tex} \mathrm { CH } _ { 3 } \mathrm { COCH } _ { 3 } {/tex}

C

{tex} \mathrm { CH } _ { 3 } \mathrm { CH } _ { 2 } \mathrm { COCH } _ { 3 } {/tex}

{tex} \mathrm { CH } _ { 3 } \mathrm { CHO } {/tex}

Explanation



Q 15.    

Correct4

Incorrect-1

The hydrocarbon which can react with sodium in liquid ammonia is

A

{tex} \mathrm { CH } _ { 3 } \mathrm { CH } _ { 2 } \mathrm { CH } _ { 2 } \mathrm { C } \equiv \mathrm { CCH } _ { 2 } \mathrm { CH } _ { 2 } \mathrm { CH } _ { 3 } {/tex}

{tex} \mathrm { CH } _ { 3 } \mathrm { CH } _ { 2 } \mathrm { C } \equiv \mathrm { CH } {/tex}

C

{tex} \mathrm { CH } _ { 3 } \mathrm { CH } = \mathrm { CHCH } _ { 3 } {/tex}

D

{tex} \mathrm { CH } _ { 3 } \mathrm { CH } _ { 2 } \mathrm { C } \equiv \mathrm { CCH } _ { 2 } \mathrm { CH } _ { 3 } {/tex}

Explanation



Q 16.    

Correct4

Incorrect-1

The treatment of {tex} \mathrm { CH } _ { 3 } \mathrm { MgX } {/tex} with {tex} \mathrm { CH } _ { 3 } \mathrm { C } \equiv \mathrm { C } - \mathrm { H } {/tex} produces

A

B

C

Explanation



Q 17.    

Correct4

Incorrect-1

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

A

propene

B

1-butene

2 -butene

D

ethene

Explanation



Q 18.    

Correct4

Incorrect-1

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

A

two ethylenic double bonds

a vinyl group

C

an isopropyl group

D

an acetylenic triple bond

Explanation



Q 19.    

Correct4

Incorrect-1

Which branched chain isomer of the hydrocarbon with molecular mass {tex}72\mathrm { u } {/tex} gives only one isomer of mono substituted alkyl halide?

A

Tertiary butyl chloride

Neopentane

C

Isohexane

D

Neohexane

Explanation

Q 20.    

Correct4

Incorrect-1

2- Hexyne gives trans- 2 -Hexene on treatment with:

A

{tex}Pt/H_2{/tex}

{tex} \mathrm { Li } / \mathrm { NH } _ { 3 } {/tex}

C

{tex} \mathrm { Pd } / \mathrm { BaSO } _ { 4 } {/tex}

D

{tex}Li AlH_4{/tex}

Explanation

Q 21.    

Correct4

Incorrect-1

Which compound would give {tex} 5 - {/tex} keto {tex} - 2 - {/tex} methylhexanal upon ozonolysis?

A

B

C

Explanation





Q 22.    

Correct4

Incorrect-1

The hottest region of Bunsen flame shown in the figure below is:

A

region 3

B

region 4

C

region 1

region 2

Explanation

Q 23.    

Correct4

Incorrect-1

At {tex}300 \mathrm { K } {/tex} and {tex} 1 \mathrm { atm } , 15 \mathrm { mL } {/tex} of a gaseous hydrocarbon requires {tex} 375\mathrm { mL } {/tex} air containing {tex}20 \% \mathrm { O } _ { 2 } {/tex} by volume for complete combustion. After combustion the gases occupy {tex}330 \mathrm { mL } {/tex} .
Assuming that the water formed is in liquid form and the volumes were measured at the same temperature and pressure, the formula of the hydrocarbon is:

A

{tex} \mathrm { C } _ { 4 } \mathrm { H } _ { 8 } {/tex}

B

{tex} \mathrm { C } _ { 4 } \mathrm { H } _ { 10 } {/tex}

C

{tex} \mathrm { C } _ { 3 } \mathrm { H } _ { 6 } {/tex}

{tex} \mathrm { C } _ { 3 } \mathrm { H } _ { 8 } {/tex}

Explanation





Q 24.    

Correct4

Incorrect-1

The reaction of propene with {tex} \mathrm { HOCl } \left( \mathrm { Cl } _ { 2 } + \mathrm { H } _ { 2 } \mathrm { O } \right) {/tex} proceeds through the intermediate:

A

{tex} \mathrm { CH } _ { 3 } - \mathrm { CH } ( \mathrm { OH } ) - \mathrm { CH } _ { 2 } ^ { + } {/tex}

B

{tex} \mathrm { CH } _ { 3 } - \mathrm { CHCl } - \mathrm { CH } _ { 2 } ^ { + } {/tex}

C

{tex} \mathrm { CH } _ { 3 } - \mathrm { CH } ^ { + } - \mathrm { CH } _ { 2 } - \mathrm { OH } {/tex}

{tex} \mathrm { CH } _ { 3 } - \mathrm { CH } ^ { + } - \mathrm { CH } _ { 2 } - \mathrm { Cl } {/tex}

Explanation



Q 25.    

Correct4

Incorrect-1

Which of these will not react with acetylene?

{tex} \mathrm { NaOH } {/tex}

B

ammonical {tex}\mathrm {AgNO}_{3}{/tex}

C

{tex} \mathrm { Na } {/tex}

D

{tex} \mathrm { HCl } {/tex}

Explanation