NEET UG · Chemistry · Aldehydes, Ketones and Carboxylic Acids

Aldol Condensation: NEET previous year questions

5 questions in ten years of NEET, in 4 of 10 papers. Pattern: Most years. Here is how it is asked and which ideas come back.

Asked in 10 years: 5; about 0.5 per paper
Years asked: 4/10; last asked 2026
Chance of a question next paper: 50%; historical rate, how we compute it
Weighted estimate: 0.4; model; history: 0.5 a paper on average, typically 0–1

Key findings

01
Asked in 4 of 10 papers, 5 questions in all: #150 of 204 topics by ten-year total. It comes back every 3.0 years on average.
02
67% of its questions since 2018 tested an idea never asked before; none repeated an idea from the year before.
03
The most repeated idea is Cross-Aldol Reaction Selectivity, asked 2 times (2020, 2022), usually as “name the reaction type”.
04
NEET has asked 4 of the 76 ideas in this topic; 68 have never been asked, directly or indirectly.
05
Mostly asked as one-line MCQ (80%); 40% easy, 40% hard.

Questions per year

Up to 2023: 0.6; per paper
Since 2024: 0.3; -0.2
Usual gap: 3.0 yrs; between papers asking it
Swing: ±0.7; questions, year to year

How it is asked

Difficulty, format and skill

Across all 5 questions on Aldol Condensation since 2017.

Difficulty

QUESTIONS

212

Easy2 · 40%
Medium1 · 20%
Hard2 · 40%

Format

One-line MCQ · 4 Q80%
Figure-based · 1 Q20%

Skill tested

Application · 2 Q40%
Multi-step · 2 Q40%
Concept · 1 Q20%

Repeats

New idea, or one asked before?

Each column is a paper. Blue questions tested an idea NEET had not asked before; navy ones went back to an idea from an earlier paper. 2017 is the first paper, so everything in it counts as new.

’17’18’19’20’21’22’23’24’25’26

Idea asked for the first time
Idea asked in an earlier paper

Coverage of the topic

NEET has asked 4 of the 76 ideas in this topic. 68 have never been asked yet.

Asked directly4 · 5%
Touched inside another question4 · 5%
Never asked68 · 89%

Ideas come from Lumi’s syllabus map of NCERT. A never-asked idea is not a safe skip: most new questions come from exactly these.

Drill down

Idea, year, question

Every idea NEET tested in this topic, with its ten papers. Open one to read the questions.

ideaAskedShareYears’17’18’19’20’21’22’23’24’25’26

Repeated2 · 40%40%2/10
- 2022 · Q90
  Which one of the following is not formed when acetone reacts with 2-pentanone in the presence of dilute NaOH followed by heating ?
  hardOne-line MCQ
- 2020 · Q107
  Reaction between benzaldehyde and acetophenone in presence of dilute NaOH is known as :
  easyOne-line MCQNew idea
1 · 20%20%1/10
1 · 20%20%1/10
1 · 20%20%1/10

Squares are the ten papers, 2017 to 2026; darker means more questions. Share is of the level above.

Ideas

Every idea inside this topic

4 different ideas were tested; 1 came more than once. Aldol Dehydration to Enones is the foundation for 26 other ideas in the syllabus.

Cross-Aldol Reaction Selectivity2×
name the reaction type
One-line MCQ · 6% next · foundation for 11
Claisen-Schmidt Condensation1×
identify compound not formed in reaction
One-line MCQ · 6% next · foundation for 1
Acetaldehyde Self-Condensation (Crotonaldehyde)1×
identify intermediate in reaction sequence
Figure-based · 4% next
Aldol Dehydration to Enones1×
predict product of reaction
One-line MCQ · 4% next · foundation for 26

Idea	Times	Format	Chance next	Foundation for
Cross-Aldol Reaction Selectivityname the reaction type	2	One-line MCQConcept	6%	11 ideas
Claisen-Schmidt Condensationidentify compound not formed in reaction	1	One-line MCQApplication	6%	1 ideas
Acetaldehyde Self-Condensation (Crotonaldehyde)identify intermediate in reaction sequence	1	Figure-basedMulti-step	4%	–
Aldol Dehydration to Enonespredict product of reaction	1	One-line MCQApplication	4%	26 ideas

Chance next is the historical rate at which an idea with this record came back in the following paper. It is low for every idea, which is why learning the topic beats memorising past questions. All repeated ideas

Every question

Aldol Condensation questions, year by year

The opening words of each question as it appeared in the official paper, with the idea it tested.

NEET 20261 question

Q82
The compound that CANNOT be obtained from the aldol condensation reaction shown below, is [2,2-dimethylcyclopentan-1-one] + PhCHO…
Idea: Claisen-Schmidt Condensation
New ideaHardOne-line MCQ · figure

NEET 20221 question

Q90
Which one of the following is not formed when acetone reacts with 2-pentanone in the presence of dilute NaOH followed by heating ?
Idea: Cross-Aldol Reaction Selectivity
HardOne-line MCQ · figure

NEET 20201 question

Q107
Reaction between benzaldehyde and acetophenone in presence of dilute NaOH is known as :
Idea: Cross-Aldol Reaction Selectivity
New ideaEasyOne-line MCQ

NEET 20172 questions

Q52
Of the following, which is the product formed when cyclohexanone undergoes aldol condensation followed by heating ?
Idea: Aldol Dehydration to Enones
EasyOne-line MCQ · figure
Q61
Consider the reactions : X ( $\mathrm{C_2H_6O}$ ) $\xrightarrow{Cu/573\ K}$ A; A $\xrightarrow{[Ag(NH_3)_2]^+,\ ^-OH,\ \Delta}$ Silver…
Idea: Acetaldehyde Self-Condensation (Crotonaldehyde)
MediumFigure-based · figure

Questions from the official NEET UG papers published by NTA (CBSE before 2019). Topic and idea tags, counts and notes are Lumi’s.