NEET > Aldehydes, Ketones and Carboxylic Acids

Explore popular questions from Aldehydes, Ketones and Carboxylic Acids for NEET. This collection covers Aldehydes, Ketones and Carboxylic Acids previous year NEET questions hand picked by popular teachers.


Q 1.    

Correct4

Incorrect-1

Consider the reactions,

Identify A,X,Y and Z.

A

A-Methoxymethane, {tex} X {/tex} -Ethanol, {tex} Y {/tex} -Ethanoic acid, {tex} \mathrm { Z } {/tex} -Semicarbazide.

A-Ethanal, {tex} X {/tex} -Ethanol, {tex} Y - \mathrm { But } - 2 {/tex} -enal, Z-Semicarbazone.

C

A-Ethanol, {tex} X {/tex} -Acetaldehyde, {tex} Y {/tex} -Butanone, Z-Hydrazone.

D

A-Methoxymethane, {tex} X {/tex} -Ethanoic acid, {tex} Y {/tex} -Acetate ion, Z-Hydrazine.

Explanation



Q 2.    

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Of the following, which is the product formed when cyclohexanone undergoes aldol condensation followed by heating?

B

C

D

Explanation

Q 3.    

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The correct structure of the product 'A' formed in the reaction

is

A

C

D

Explanation



Q 4.    

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The correct order of strengths of the carboxylic asids.

A

{tex} I > II > I I {/tex}

{tex} II > III > I {/tex}

C

{tex} III > II > I{/tex}

D

{tex} II > I > I I I {/tex}

Explanation



Q 5.    

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Which of the following reagents would distinguish cis-cyclopenta-1-2-diol from the trans-isomer?

A

{tex} \mathrm { MnO } _ { 2 } {/tex}

B

Aluminium isopropoxide

Acetone

D

Ozone

Explanation



Q 6.    

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The correct statement regarding a carbonyl compound with a hydrogen atom on its alpha- carbon, is

A

a carbonyl compound with a hydrogen atom on its alpha-carbon rapidly equilibrates with its corresponding enol and this process is known as carbonylation

a carbonyl compound with a hydrogen atom on its alpha-carbon rapidly equilibrates with its corresponding enol and this process is known as keto-enol tautomerism

C

a carbonyl compound with a hydrogen atom on its alpha-carbon never equilibrates with its corresponding enol

D

a carbonyl compound with a hydrogen atom on its alpha-carbon rapidly equilibrates with its corresponding enol and this process is known as aldehyde-ketone equilibration.

Explanation

Q 7.    

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The oxidation of benzene by {tex} \mathrm { V } _ { 2 } \mathrm { O } _ { 5 } {/tex} in the presence of air produces

maleic anhydride

B

benzoic acid

C

benzaldehyde

D

benzoic anhydride.

Explanation



Q 8.    

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Reaction of a carbonyl compound with one of the following reagents involves nucleophilic addition followed by elimination of water. The reagent is

hydrazine in presence of feebly acidic solution

B

hydrocyanic acid

C

sodium hydrogen sulphite

D

a Grignard reagent

Explanation



Q 9.    

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Which one of the following esters gets hydrolysed most easily under alkaline conditions?

A

B

C

Explanation



Q 10.    

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An organic compound 'X' having molecular formula {tex}C_{5}H_{10}O{/tex} yields phenylhydrazone and gives negative response to the iodoform test and Tollens' test. It produces n-pentane on reduction. 'X' could be

3-pentanone

B

n-amyl alcohol

C

pentanal

D

2-pentanone.

Explanation



Q 11.    

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Incorrect-1

Which one is most reactive towards nucleophilic addition reaction?

A

B

C

Explanation



Q 12.    

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The order of stability of the following tautomeric compounds is

A

{tex}\mathrm {II} > \mathrm {I} >\mathrm {I I I }{/tex}

B

{tex}\mathrm{ II} >\mathrm{ I I I} >\mathrm{ I }{/tex}

C

{tex} \mathrm { I } > \mathrm { II } > \mathrm { III } {/tex}

{tex} \mathrm { III } > \mathrm { II } > \mathrm { I } {/tex}

Explanation

Q 13.    

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Reaction by which benzaldehyde cannot be prepared

A

C

D

Explanation



Q 14.    

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Predict the products in the given reaction.

A

B

D

Explanation





Q 15.    

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Acetone is treated with excess of ethanol in the presence of hydrochloric acid. The product obtained is

A

B

C

Explanation

Q 16.    

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{tex} \mathrm { CH } _ { 3 } \mathrm { CHO } {/tex} and {tex} \mathrm { C } _ { 6 } \mathrm { H } _ { 5 } \mathrm { CH } _ { 2 } \mathrm { CHO } \quad {/tex} can {tex} \quad \mathrm { be } {/tex} distinguished chemically by

A

Benedict's test

Iodoform test

C

Tollen's reagent test

D

Fehling's solution test

Explanation



Q 17.    

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The correct order of decreasing acid strengtt of trichloroacetic acid {tex} ( A ) , {/tex} trifluoroacetic acic {tex} ( B ) , {/tex} acetic acid {tex} ( C ) {/tex} and formic acid {tex} ( D ) {/tex} is

{tex} B > A > D > C {/tex}

B

{tex} B > D > C > A {/tex}

C

{tex} A > B > C > D {/tex}

D

{tex} A > C > B > D {/tex}

Explanation



Q 18.    

Correct4

Incorrect-1

Consider the following reaction

The product A is

{tex} \mathrm { C } _ { 6 } \mathrm { H } _ { 5 } \mathrm { CHO } {/tex}

B

{tex} \mathrm { C } _ { 6 } \mathrm { H } _ { 5 } \mathrm { OH } {/tex}

C

{tex} \mathrm { C } _ { 6 } \mathrm { H } _ { 5 } \mathrm { COCH } _ { 3 } {/tex}

D

{tex} \mathrm { C } _ { 6 } \mathrm { H } _ { 5 } \mathrm { Cl } {/tex}

Explanation



Q 19.    

Correct4

Incorrect-1

Consider the reaction : {tex} R \mathrm { CHO } + \mathrm { NH } _ { 2 } \mathrm { NH } _ { 2 } \rightarrow R \mathrm { CH } = \mathrm { N } - \mathrm { NH } _ { 2 } {/tex} What sort of reaction is it?

A

Electrophilic addition-elimination reaction

B

Free radical addition-elimination reaction

C

Electrophilic substitution-elimination reaction

Nucleophilic addition-elimination reaction

Explanation

Q 20.    

Correct4

Incorrect-1

Which of the following compounds will give a yellow precipitate with iodine and alkali?

Acetophenone

B

Methyl acetate

C

Acetamide

D

None of these

Explanation





Q 21.    

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Incorrect-1

Clemmensen reduction of a ketone is carried out in the presence of which of the following?

A

Glycol with KOH

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

C

{tex}LiAlH_{4}{/tex}

D

{tex} \mathrm { H } _ { 2 } {/tex} and {tex} \mathrm { Pt } {/tex} as catalyst

Explanation



Q 22.    

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In a set of reactions m-bromobenzoic acid give a product D. Identify the product D.

A

B

D

Explanation

Q 23.    

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Incorrect-1

The order of reactivity of phenyl magnesium bromide (PhMgBr) with the following compounds:

A

{tex} \mathrm { II } > \mathrm { II } > \mathrm { I } {/tex}

B

{tex} \mathrm { II } > \mathrm { I } > \mathrm { III } {/tex}

C

{tex} \mathrm { I } > \mathrm { III } > \mathrm { II } {/tex}

{tex} \mathrm { I } > \mathrm { II } > \mathrm { III } {/tex}

Explanation



Q 24.    

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Incorrect-1

Match the compounds given in List-I with List-II and select the suitable option using the code given below.

A

{tex} ( \mathrm { A } ) - ( \mathrm { iv } ) , ( \mathrm { B } ) - ( \mathrm { i } ) , ( \mathrm { C } ) - ( \mathrm { iii } ) , ( \mathrm { D } ) - ( \mathrm { ii } ) {/tex}

B

{tex} ( \mathrm { A } ) - ( \mathrm { iv } ) , ( \mathrm { B } ) - ( \mathrm { ii } ) , ( \mathrm { C } ) - ( \mathrm { iii } ) , ( \mathrm { D } ) - \mathrm { i } {/tex}

C

{tex} ( \mathrm { A } ) - ( \mathrm { ii } ) , ( \mathrm { B } ) - ( \mathrm { iii } ) , ( \mathrm { C } ) - ( \mathrm { iv } ) , ( \mathrm { D } ) - \mathrm { i } {/tex}

{tex} ( \mathrm { A } ) - ( \mathrm { ii } ) , ( \mathrm { B } ) - ( \mathrm { i } ) , ( \mathrm { C } ) - ( \mathrm { i } \mathrm { v } ) , ( \mathrm { D } ) - ( \mathrm { iii } ) {/tex}

Explanation

Q 25.    

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Incorrect-1

An organic compound A on treatment with {tex}NH_{3}{/tex} gives B, which on heating gives C. C when treated with {tex}Br_{2}{/tex} in the presence of KOH produces ethyl amine. Compound A is

A

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

B

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

C

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

Explanation