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JEE Main

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

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Q 1. Which of the following statements regarding ethanoic acid and methyl methanoate are correct?
I. They are functional group isomers with molecular formula {tex} \mathrm { C } _ { 2 } \mathrm { H } _ { 4 } \mathrm { O } _ { 2 } {/tex}.
II. They belong to same homologous series.
III. They have different chemical properties.

A

I and II

I and III

C

II and III

D

I, II and III

Explanation

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Q 2. How many structural isomers are possible for compounds containing {tex} \mathrm { C } , \mathrm { H } {/tex} and {tex} \mathrm { O } {/tex} atoms only with their molar masses 100 as well as the isomers are simultaneously ketones?

A

3

B

4

C

5

6

Explanation

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Q 3. How many structural isomer are possible with the molecular formula {tex} \mathrm { C } _ { 8 } \mathrm { H } _ { 10 } {/tex}

A

3

B

4

5

D

6

Explanation

Double bond equivalent =

there is either 4 double bond or 1 ring- 3 double bond possible or 2 double bond, 2 ring or 2 triple bond etc
This is the compound having 4 double bond equivalent
Thus 5 structural isomers are possible.

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Q 4. How many different secondary halide names can be assigned to the compounds with molecular formula {tex} \mathrm { C } _ { 5 } \mathrm { H } _ { 11 } \mathrm { Cl } {/tex} (excluding stereoisomers)?

3

B

4

C

5

D

7

Explanation



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Q 5. Which of the following compounds will not show geometrical isomerism?

A

3-Phenyl-2-propenoic acid

B

2 -Butene

3-Methyl-2-butenoic acid

D

3-Methyl-2-pentenoic acid

Explanation

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Q 6. Which of the following will have zero dipole moment?

A

cis-1, 2-Dichloroethene

trans-1, 2-Dichloroethene

C

{tex}trans{/tex}-1, 2-Dichloropropene

D

2-Pentyne

Explanation

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Q 7. Which of the following compounds exhibits stereioisomerism?

A

2-Mehylbutene

B

3-Methylbutyne

C

3-Methylbutanoic acid

2-Methylbutanoic acid

Explanation

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Q 8.

A

Enantiomer

Diastereomer

C

Identical

D

Structural isomer

Explanation

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Q 9. How many amide isomers are possible for {tex} \mathrm { C } _ { \mathrm { 4 } } \mathrm { H } _ { \mathrm { 9 } } \mathrm { ON } ? {/tex}

A

4

B

5

C

6

8

Explanation



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Q 10. Order of stability of enol content:

A

{tex} a > b > c {/tex}

B

{tex} b > a > c {/tex}

{tex} b > c > a {/tex}

D

{tex} a > c > b {/tex}

Explanation

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Q 11. The correct order of the substituent in each of the following set in order of priority according to CIP rule

A

{tex} - \mathrm { Cl } > - \mathrm { OH } > - \mathrm { SH } > \mathrm { H } {/tex}

{tex} - \mathrm { CH } _ { 2 } - \mathrm { Br } > - \mathrm { CH } _ { 2 } - \mathrm { Cl } > - \mathrm { CH } _ { 2 } - \mathrm { OH } > - \mathrm { CH } _ { 3 } {/tex}

C

{tex} - \mathrm { CH } = \mathrm { O } > - \mathrm { OH } > - \mathrm { CH } _ { 3 } > - \mathrm { H } {/tex}

D

{tex} - \mathrm { OCH } _ { 3 } > - \mathrm { N } \left( \mathrm { CH } _ { 3 } \right) _ { 2 } > - \mathrm { CH } _ { 3 } > - \mathrm { CD } _ { 3 } {/tex}

Explanation

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Q 12. Consider the following compounds,

The correct {tex} E / Z {/tex} configurational notations for the compounds I to II are respectively-

{tex} \mathrm { Z } , \mathrm { Z } {/tex}

B

{tex} \mathrm { E } , \mathrm { Z } {/tex}

C

{tex} Z ,E {/tex}

D

{tex} \mathrm { E } , \mathrm { E } {/tex}

Explanation

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Q 13. Calculate the number of stereoisomerism for

A

2

4

C

8

D

6

Explanation

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Q 14. The number of stereoisomers possible for the compound is-

A

2

4

C

6

D

8

Explanation

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Q 15.
a and {tex} b {/tex} are stereoismers sum of {tex} ( a + b = ? ) {/tex}

A

4

6

C

8

D

12

Explanation

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Q 16. How many different isomer can be given to bromodichlorobenzene?

A

3

B

4

6

D

7

Explanation

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Q 17. Which of following compound will not show geometrical isomerism?

A

B

D

Explanation

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Q 18. Which of the following compound is chiral?

A

C

D

Explanation


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Q 19. Which two of the following compounds are identical?

A

I & II

II & IV

C

III & IV

D

I & III

Explanation

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Q 20. How many different structural isomers exist for {tex} \mathrm { C } _ { 5 } \mathrm { H } _ { 8 } {/tex} that have only {tex} \mathrm { sp } ^ { 3 } {/tex} -hybridised carbon atoms?

A

3

B

4

5

D

7

Explanation

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Q 21. Which of following reagents does not give isobutane when reacted with isobutyl magnesium bromide?

A

B

C

{tex} \mathrm { PhOCH } _ { 3 } {/tex}

Explanation

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Q 22. Methane as well as ethane can be obtained in one step (in two separate reactions) from

A

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

B

{tex} \mathrm { C } _ { 2 } \mathrm { H } _ { 5 } \mathrm { OH } {/tex}

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

D

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

Explanation

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Q 23. An alkane of molecular weight 86 gives on mono-chlorination two product. The alkane is

A

2-Methylbutane

B

n-butane

C

2, 2-Dimethyl propane

2, 3-Dimethyl butane

Explanation

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Q 24. Which of the following alkanes will give a single product with a methylene insertion?

{tex} \mathrm { Me } _ { 4 } \mathrm { C } {/tex}

B

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

C

{tex} \mathrm { Me } _ { 2 } \mathrm { CHCHMe } _ { 2 } {/tex}

D

{tex} \mathrm { MeCH } _ { 2 } \mathrm { C } ( \mathrm { Me } ) _ { 2 } \mathrm { CH } _ { 2 } \mathrm { CH } _ { 3 } {/tex}

Explanation

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Q 25. monochloro structural isomers for compound {tex}C_5H_{10}{/tex} how many pairs of geometrical isomers are possible?

1

B

2

C

3

D

None

Explanation