NEET Previous Year Questions (2014-2024): Aldehydes, Ketones & Carboxylic Acids | Chemistry Class 12 PDF Download

2024

Q2: Match List I with List II.

Choose the correct answer from the options given below:
(a) A-IV, B-I, C-III, D-II
(b) A-III, B-I, C-II, D-IV
(c) A-IV, B-I, C-II, D-III
(d) A-I, B-IV, C-II, D-III        (NEET 2024)
Ans: (c)

Q3: For the given reaction:

'P' is
(a)
(b)
(c)
(d)       (NEET 2024)
Ans: (b)

2023

[C] is _______.

(a)

(b)

(c)

(d)

Ans: (c)

Q2: Identify the major product obtained in the following reaction:      (NEET 2023)
3 ^– OH  major product
(a)
(b)
(c)
(d)
Ans: (c)
Ammoniacal silver nitrate solution is Tollens’ reagent. Tollens’ reagent can be used to distinguish aldehyde & ketone as aldehyde upon warming with Tollens’ reagent produces a silver mirror due to formation of silver metal in alkaline medium. Aldehyde is oxidised to corresponding carboxylate anion.

Q3: Identify the final product [D] obtained in the following sequence of reactions.     (NEET 2023)

(a)

(b) C3H10

(c)

(d)
Ans: (d)

2022

Q1:
What is Y in the above reaction?    (NEET 2022 Phase 1)
(a) RCOO^-X⁺ 
(b) (RCOO)₂Mg
(c) RCOO^-Mg⁺X
(d) R₃CO^-Mg⁺X
Ans: (c)


Q2: Given below are two statements:  
Statement I: The boiling points of aldehydes and ketones are higher than hydrocarbons of comparable molecular masses because of weak molecular association in aldehydes and ketones due to dipole-dipole interactions.  
Statement II: The boiling points of aldehydes and ketones are lower than the alcohols of similar molecular masses due to the absence of H-bonding.
In the light of the above statements, choose the most appropriate answer from the options given below:   (NEET 2022 Phase 1)
(a) Statement I is correct but Statement II is incorrect.  
(b) Statement I is incorrect but Statement II is correct.
(c) Both Statement I and Statement II are correct.
(d) Both Statement I and Statement II are incorrect.
Ans: (c)

• The boiling points of aldehydes and ketones are higher than hydrocarbons of comparable molecular masses due to weak molecular association in aldehydes and ketones arising out of the dipole - dipole interaction.
• Acohols involved intermolecular hydrogen bonding, because of which the boiling point of aldehydes and ketones are lower than the alcohols of similar molecular masses.

Q3: Match List-I with List -II.
from the options given below correct answer Choose the    (NEET 2022 Phase 1)

(a) (a) – (i), (b) – (iii), (c) – (ii), (d) – (iv)
(b) (a) – (iv), (b) – (iii), (c) – (ii), (d) – (i)
(c) (a) – (iii), (b) – (iv), (c) – (ii), (d) – (i)
(d) (a) – (ii), (b) – (iii), (c) – (iv), (d) – (i)
Ans: (b)
Cyanohydrin → HCN
Acetal → Alcohol
Schiff's base → R–NH₂
Oxime → NH₂–OH

Q4: Which one of the following is not formed when acetone reacts with 2-pentanone in the presence of dilute NaOH followed by heating?    (NEET 2022 Phase 1)
(a)
(b)
(c)
(d)
Ans: (d)

Q5: Compound X on reaction with O₃ followed by Zn/H₂O gives formaldehyde and 2-methyl propanal as products. The compound X is
(a) 3-Methylbut-1-ene
(b) 2-Methylbut-1-ene
(c) 2-Methylbut-2-ene
(d) Pent-2-ene     (NEET 2022 Phase 1)
Ans: (a)

Q6: The incorrect method to synthesize benzaldehyde is      (NEET 2022 Phase 2)

(a)

(b)

(c)

(d)

Ans: (a)

Q7: Match List-I with List-II :      (NEET 2022 Phase 2)

Choose the correct answer from the options given below :
(a) (a) - (iii), (b) - (iv), (c) - (ii), (d) - (i)
(b) (a) - (iii), (b) - (i), (c) - (ii), (d) - (iv)
(c) (a) - (ii), (b) - (iii), (c) - (i), (d) - (iv)
(d) (a) - (iv), (b) - (iii), (c) - (i), (d) - (ii)
Ans: (a)

• Gabriel phthalimide synthesis is used for preparation of aliphatic primary amines.
• Kolbe synthesis with phenol gives salicylic acid
• Williamson synthesis gives ether on reaction of alkyl halide and alcoxide
• Etard reaction gives benzaldehyde from benzene

Q8: The product formed from the following reaction sequence is     (NEET 2022 Phase 2)

(a)

(b)

(c)

(d)

Ans: (c)

Q9: Which of the following reactions is not an example for nucleophilic addition-elimination reaction?
(a) CH₃CHO + NH₃ $\rightleftharpoons$ CH₃CH = NH + H₂O 
(b)
(c) CH₃CHO + NH₂OH $\rightleftharpoons$ CH₃CH = N $-$ OH + H₂O 
(d) CH₃CHO + C₆H₅NHNH₂ $\rightleftharpoons$ CH₃CH = N $-$ NHC₆H₅ + H₂O      (NEET 2022 Phase 2)
Ans: (b)
It is an example of nucleophilic addition reaction

2021

Q1:
Consider the above reaction and identify the missing reagent/chemical.     (NEET 2021)
(a) CaO
(b) DIBAL-H
(c) B₂H₆
(d) Red Phosphorus
Ans: (a)
Decarboxylation takes place by soda-lime (NaOH + CaO)

Q2:  Match List-I with List-II.     (NEET 2021)
Choose the correct answer from the options given below.
(a) (a)-(i), (b)-(iv), (c)-(iii), (d)-(ii)
(b) (a)-(ii), (b)-(iii), (c)-(iv), (d)-(i)
(c) (a)-(iv), (b)-(i), (c)-(ii), (d)-(iii)
(d) (a)-(iii), (b)-(ii), (c)-(i), (d)-(iv)
Ans: (b)


Q3:  The product formed in the following chemical reaction is :     (NEET 2021)
 
(a)  
(b)  
(c)
(d)  
Ans: (b)
NaBH₄ is a reducing agent. If reduces carbonyl group into alcohols but does not reduce esters.


Q4: The intermediate compound 'X' in the following chemical reaction is :     (NEET 2021)

(a)
(b)
(c)
(d)
Ans: (c)
This is Etard reaction in which reaction of toluene with chromyl chloride in CCl₄ followed by hydrolysis gives benzaldehyde. Toluene reacts with chromyl chloride to form a precipitate called the Etard complex.

Q5: What is the IUPAC name of the organic compound formed in the following chemical reaction?

(a) 2-methylbutan-2-ol
(b) 2-methylpropan-2-ol
(c) pentan-2-ol
(d) pentan-3-ol
Ans: (a)

IUPAC name of product is 2-methylbutan-2-ol.

2020

Q1: Identify compound X in the following sequences of reactions :     (NEET 2020)

(a)

(b)

(c)

(d)

Ans: (a)

Q2: Reaction between benzaldehyde and acetophenone in presence of dilute NaOH is known as:      (NEET 2020)
(a) Cross Cannizzaro’s reaction
(b) Cross Aldol condensation 
(c) Aldol condensation 
(d) Cannizzaro’s reaction
Ans: (b)
In the presence of dil. OH^- , benzaldehyde and acetophenone will react to undergo cross-aldol condensation. 

Q3: Reaction between acetone and methylmagnesium chloride followed by hydrolysis will give :
(a) Sec. butyl alcohol
(b) Tert. butyl alcohol
(c) Isobutyl alcohol
(d) Isopropyl alcohol            (NEET 2020)
Ans: (b) 

2018

Q1: Carboxylic acid have higher boiling points than aldehydes, ketones and even alcohols of comparable molecular mass. It is due to their     (NEET 2018)
(a) formation of intramolecular H-bonding
(b) formation of carboxylate ion
(c) more extensive association of carboxylic acid via vander Wall force of attraction
(d) formation of intermolecular H-bonding.
Ans: (d)
Due to the formation of intermolecular H-bonding, association occurs in carboxylic acids. So, they have higher boiling points than aldehydes, ketones and even alcohols of comparable molecular mass.

2017

Q1: Consider the reactions :-    (NEET 2017)