NEET > Organic Chemistry Some Basic Principles and Techniques

Explore popular questions from Organic Chemistry Some Basic Principles and Techniques for NEET. This collection covers Organic Chemistry Some Basic Principles and Techniques previous year NEET questions hand picked by popular teachers.


Q 1.    

Correct4

Incorrect-1

The most suitable method of separation of {tex} 1 : 1 {/tex} mixture of {tex}ortho{/tex} and {tex}para{/tex}-nitrophenols is

A

chromatography

B

crystallisation

steam distillation

D

sublimation.

Explanation



Q 2.    

Correct4

Incorrect-1

The IUPAC name of the compound is

A

5-formylhex-2-en-3-one

B

5-methyl- 4 -oxohex- 2 -en- 5 - al

C

3-keto-2-methylhex-5-enal

3-keto-2-methylhex-4-enal

Explanation

Q 3.    

Correct4

Incorrect-1

The correct statement regarding electrophile is

A

electrophile is a negatively charged species and can form a bond by accepting a pair of electrons from another electrophile

B

electrophiles are generally neutral species and can form a bond by accepting a pair of electrons from a nucleophile

electrophile can be either neutral or positively charged species and can form a bond by accepting a pair of electrons from a nucleophile

D

electrophile is a negatively charged species and can form a bond by accepting a pair of electrons from a nucleophile.

Explanation

Q 4.    

Correct4

Incorrect-1

Which among the given molecules can exhibit tautomerism?

III only

B

Both I and III

C

Both I and II

D

Both II and III

Explanation



Q 5.    

Correct4

Incorrect-1

Which of the following biphenyls is optically active?

A

B

C

Explanation


Q 6.    

Correct4

Incorrect-1

For the following reactions


Which of the following statements is correct?

A

(A) is elimination, (B) and (C) are substitution reactions.

B

(A) is substitution, (B) and (C) are addition reactions.

C

(A) and (B) are elimination reactions and (C) is addition reaction.

(A) is elimination, ( B) is substitution and (C) is addition reaction.

Explanation





Q 7.    

Correct4

Incorrect-1

Which of the following statements is not correct for a nucleophile?

A

Ammonia is a nucleophile.

B

Nucleophiles attack low {tex} e ^ { - } {/tex} density sites.

C

Nucleophiles are not electron seeking.

Nucleophile is a Lewis acid.

Explanation


Q 8.    

Correct4

Incorrect-1

Which of the following is not the product of dehydration of ?

B

C

D

Explanation



Q 9.    

Correct4

Incorrect-1

Treatment of cyclopentanone with methyl lithium gives which of the following species?

A

Cyclopentanonyl radical

B

Cyclopentanonyl biradical

Cyclopentanonyl anion

D

Cyclopentanonyl cation

Explanation

Q 10.    

Correct4

Incorrect-1

The total number of {tex} \pi {/tex} -bond electrons in the following structure is

A

12

B

16

C

4

8

Explanation


Q 11.    

Correct4

Incorrect-1

Which of the following species contains equal number of {tex} \sigma {/tex} - and {tex} \pi {/tex} -bonds?

A

{tex} ( \mathrm { CN } )_{2} {/tex}

B

{tex} \mathrm { CH } _ { 2 } ( \mathrm { CN } ) _ { 2 } {/tex}

C

{tex} \mathrm { {HCO}^{-} _ { 3 }} {/tex}

{tex} \mathrm { XeO } _ { 4 } {/tex}

Explanation



Q 12.    

Correct4

Incorrect-1

Given:

Which of the given compounds can exhibit tautomerism?

A

II and III

I, II and III

C

I and II

D

I and III

Explanation



Q 13.    

Correct4

Incorrect-1

Which of the following is the most correct electron displacement for a nucleophilic reaction to take place?

B

C

D

Explanation



Q 14.    

Correct4

Incorrect-1

In Duma's method for estimation of nitrogen, 0.25 g of an organic compound gave 40 mL of nitrogen collected at 300 K temperature and 725 mm presure. If the aqueous tension at 300 K is 25 mm, the percentage of nitrogen in the compound is

16.76

B

15.76

C

17.36

D

18.20

Explanation



Q 15.    

Correct4

Incorrect-1

Consider the following compounds

Hyperconjugation occurs in

III only

B

I and III

C

I only

D

II only.

Explanation


Q 16.    

Correct4

Incorrect-1

The enolic form of ethyl acetoacetate as shown below has

A

9 sigma bonds and 2 pi-bonds

B

9 sigma bonds and 1 pi-bond

18 sigma bonds and 2 pi-bonds

D

16 sigma bonds and 1 pi-bond.

Explanation

Q 17.    

Correct4

Incorrect-1

In which of the following compounds, the C- Cl bond ionisation shall give most stable carbonium ion?

A

B

C

Explanation



Q 18.    

Correct4

Incorrect-1

In the Kjeldahl's method for estimation of nitrogen present in a soil sample, ammonia evolved from 0.75 g of sample neutralized 10{tex} \mathrm { mL } {/tex} of 1M {tex} \mathrm { H } _ { 2 } \mathrm { SO } _ { 4 } {/tex} . The percentage of nitrogen in the soil is

37.33

B

45.33

C

35.33

D

43.33

Explanation



Q 19.    

Correct4

Incorrect-1

The radical, is aromatic because it has

A

7 {tex} p {/tex} -orbitals and 7 unpaired electrons

B

6{tex} p {/tex} -orbitals and 7 unpaired electrons

6 {tex} p {/tex} -orbitals and 6 unpaired electrons

D

7 {tex} p {/tex} -orbitals and 6 unpaired electrons.

Explanation

Q 20.    

Correct4

Incorrect-1

The structure of isobutyl group in an organic compound is

A

B

D

Explanation

Q 21.    

Correct4

Incorrect-1

Structure of the compound whose IUPAC name is 3-Ethyl-2-hydroxy-4-methylhex-3-en- 5 -ynoic acid is

A

B

C

Explanation


Q 22.    

Correct4

Incorrect-1

Some {tex}meta{/tex}-directing substituents in aromatic substitution are given. Which one is most deactivating?

A

{tex} - \mathrm { COOH } {/tex}

{tex} - \mathrm { NO } _ { 2 } {/tex}

C

{tex} - \mathrm { C } \equiv \mathrm { N } {/tex}

D

{tex} - \mathrm { SO } _ { 3 } \mathrm { H } {/tex}

Explanation


Q 23.    

Correct4

Incorrect-1

Arrange the following in increasing order of stability

{tex} 5 < 4 < 3 < 1 < 2 {/tex}

B

{tex} 4 < 5 < 3 < 1 < 2 {/tex}

C

{tex} 1 < 5 < 4 < 3 < 2 {/tex}

D

{tex} 5 < 4 < 3 < 2 < 1 {/tex}

Explanation


Q 24.    

Correct4

Incorrect-1

What is the hybridisation state of benzyl carbonium ion ?

{tex} s p ^ { 2 }{/tex}

B

{tex} s p d ^ { 2 } {/tex}

C

{tex} s p ^ { 2 } d {/tex}

D

{tex} s p ^ { 3 } {/tex}

Explanation

Q 25.    

Correct4

Incorrect-1

Nitrogen detection in an organic compound is carried out by Lassaigne's test. The blue colour formed corresponds to which of the following formulae?

A

{tex} \mathrm { Fe } _ { 3 } \left[ \mathrm { Fe } ( \mathrm { CN } ) _ { 6 } \right] _ { 2 } {/tex}

{tex} \mathrm { Fe } _ { 4 } \left[ \mathrm { Fe } ( \mathrm { CN } ) _ { 6 } \right] _ { 3 } {/tex}

C

{tex} \mathrm { Fe } _ { 4 } \left[ \mathrm { Fe } ( \mathrm { CN } ) _ { 6 } \right] _ { 2 } {/tex}

D

{tex} \mathrm { Fe } _ { 3 } \left[ \mathrm { Fe } ( \mathrm { CN } ) _ { 6 } \right] _ { 3 } {/tex}

Explanation