NEET UG · Chemistry · Hydrocarbons

Hydrocarbons (Alkenes): NEET previous year questions

12 questions in ten years of NEET, in 7 of 10 papers. Pattern: Every year. Here is how it is asked and which ideas come back.

Asked in 10 years: 12; about 1.1 per paper
Years asked: 7/10; last asked 2026
Chance of a question next paper: 84%; historical rate, how we compute it
Weighted estimate: 1.6; model; history: 1.2 a paper on average, typically 0–2

Key findings

01
Asked in 7 of 10 papers, 12 questions in all: #52 of 204 topics by ten-year total. It comes back every 1.2 years on average.
02
83% of its questions since 2018 tested an idea never asked before; 1 repeated an idea from the year before.
03
The most repeated idea is Aromaticity and Huckel's Rule, asked 2 times (2022, 2023), usually as “count species obeying a rule”.
04
NEET has asked 8 of the 82 ideas in this topic; 62 have never been asked, directly or indirectly.
05
Mostly asked as one-line MCQ (83%); 33% easy, 17% hard, and up from 0.9 to 1.7 questions a paper since 2024.

Questions per year

Up to 2023: 0.9; per paper
Since 2024: 1.7; +0.7
Usual gap: 1.2 yrs; between papers asking it
Swing: ±1.0; questions, year to year

Recent framings

statement I/II on alkene addition stereochemistry
identify relation among reaction products
identify structure with a given feature

Revise first

Stability of Diene Systems (2026); Halogen Addition Stereochemistry (2026); Lindlar's Catalyst Reduction (2026)

How it is asked

Difficulty, format and skill

Across all 12 questions on Hydrocarbons (Alkenes) since 2017.

Difficulty

QUESTIONS

462

Easy4 · 33%
Medium6 · 50%
Hard2 · 17%

Format

One-line MCQ · 10 Q83%
Two statements · 1 Q8%
Figure-based · 1 Q8%

Skill tested

Application · 8 Q67%
Multi-step · 2 Q17%
Recall · 1 Q8%
Figure reading · 1 Q8%

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 8 of the 82 ideas in this topic. 62 have never been asked yet.

81262

Asked directly8 · 10%
Touched inside another question12 · 15%
Never asked62 · 76%

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 · 17%17%2/10
- 2023 · Q98
  Consider the following compounds/species : i. [structure: naphthalene] ii. [structure: cyclopentadienyl anion] iii. [structure:…
  mediumOne-line MCQAsked the year before
- 2022 · Q54
  Which compound amongst the following is not an aromatic compound ?
  mediumOne-line MCQNew idea
Repeated2 · 17%17%2/10
1 · 8%8%1/10
1 · 8%8%1/10
1 · 8%8%1/10
1 · 8%8%1/10
1 · 8%8%1/10
1 · 8%8%1/10
1 · 8%8%1/10
1 · 8%8%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

10 different ideas were tested; 2 came more than once. Geometrical Isomerism (Cis/Trans & E/Z) is the foundation for 21 other ideas in the syllabus.

Aromaticity and Huckel's Rule2×
count species obeying a rule
One-line MCQ · 6% next
Reverse Ozonolysis (Parent Alkene Identification)2×
identify alkene from ozonolysis products
One-line MCQ · 6% next
Halogen Addition Stereochemistry1×
statement i/ii on alkene addition stereochemistry
Two statements · 6% next · foundation for 8
Lindlar's Catalyst Reduction1×
identify relation among reaction products
One-line MCQ · 6% next
Stability of Diene Systems1×
identify structure with a given feature
One-line MCQ · 6% next
Bromine Water Test for Unsaturation1×
identify compound not decolourizing bromine water
One-line MCQ · 6% next
Geometrical Isomerism (Cis/Trans & E/Z)1×
identify compound showing cis-trans isomerism
One-line MCQ · 6% next · foundation for 21
Nomenclature of Alkenes1×
match name to structure
Figure-based · 4% next
Peroxide Effect (Anti-Markovnikov)1×
predict product of reaction
One-line MCQ · 4% next · foundation for 3
Retro-Ozonolysis (Reactant Identification)1×
identify alkene from ozonolysis product
One-line MCQ · 4% next

Idea	Times	Format	Chance next	Foundation for
Aromaticity and Huckel's Rulecount species obeying a rule	2	One-line MCQApplication	6%	–
Reverse Ozonolysis (Parent Alkene Identification)identify alkene from ozonolysis products	2	One-line MCQApplication	6%	–
Halogen Addition Stereochemistrystatement i/ii on alkene addition stereochemistry	1	Two statementsApplication	6%	8 ideas
Lindlar's Catalyst Reductionidentify relation among reaction products	1	One-line MCQMulti-step	6%	–
Stability of Diene Systemsidentify structure with a given feature	1	One-line MCQRecall	6%	–
Bromine Water Test for Unsaturationidentify compound not decolourizing bromine water	1	One-line MCQApplication	6%	–
Geometrical Isomerism (Cis/Trans & E/Z)identify compound showing cis-trans isomerism	1	One-line MCQApplication	6%	21 ideas
Nomenclature of Alkenesmatch name to structure	1	Figure-basedFigure reading	4%	–
Peroxide Effect (Anti-Markovnikov)predict product of reaction	1	One-line MCQApplication	4%	3 ideas
Retro-Ozonolysis (Reactant Identification)identify alkene from ozonolysis product	1	One-line MCQApplication	4%	–

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

Hydrocarbons (Alkenes) questions, year by year

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

NEET 20263 questions

Q76
Given below are two statements: Statement I : trans-But-2-ene upon treatment with $\mathrm{Br_2}$ in $\mathrm{CCl_4}$ gives the following…
Idea: Halogen Addition Stereochemistry
New ideaHardTwo statements · figure
Q77
Consider the following reaction sequences and choose the correct option. L $\xleftarrow{\text{Na/liq. NH}_3}$ Ph–C≡C–Me…
Idea: Lindlar's Catalyst Reduction
New ideaHardOne-line MCQ · figure
Q83
Among the following, the compound having conjugated double bonds is
Idea: Stability of Diene Systems
New ideaEasyOne-line MCQ

NEET 20252 questions

Q58
Which one of the following compounds can exist as cis-trans isomers?
Idea: Geometrical Isomerism (Cis/Trans & E/Z)
New ideaMediumOne-line MCQ
Q77
Which one of the following compounds does not decolourize bromine water?
Idea: Bromine Water Test for Unsaturation
New ideaEasyOne-line MCQ · figure

NEET 20231 question

Q98
Consider the following compounds/species : i. [structure: naphthalene] ii. [structure: cyclopentadienyl anion] iii. [structure:…
Idea: Aromaticity and Huckel's Rule
Asked last yearMediumOne-line MCQ · figure

NEET 20222 questions

Q54
Which compound amongst the following is not an aromatic compound ?
Idea: Aromaticity and Huckel's Rule
New ideaMediumOne-line MCQ · figure
Q91
Compound X on reaction with $\mathrm{O_3}$ followed by Zn/ $\mathrm{H_2O}$ gives formaldehyde and 2-methyl propanal as products. The…
Idea: Reverse Ozonolysis (Parent Alkene Identification)
MediumOne-line MCQ

NEET 20212 questions

Q63
The correct structure of 2,6-Dimethyl-dec-4-ene is :
Idea: Nomenclature of Alkenes
New ideaEasyFigure-based · figure
Q80
The major product of the following chemical reaction is : $\mathrm{(CH_3)_2CH-CH=CH_2 + HBr \xrightarrow{(C_6H_5CO)_2O_2} ?}$
Idea: Peroxide Effect (Anti-Markovnikov)
New ideaEasyOne-line MCQ · figure

NEET 20201 question

Q133
An alkene on ozonolysis gives methanal as one of the product. Its structure is :
Idea: Retro-Ozonolysis (Reactant Identification)
New ideaMediumOne-line MCQ · figure

NEET 20191 question

Q74
An alkene "A" on reaction with $O_3$ and $Zn-H_2O$ gives propanone and ethanal in equimolar ratio. Addition of HCl to alkene "A" gives "B"…
Idea: Reverse Ozonolysis (Parent Alkene Identification)
New ideaMediumOne-line MCQ · figure

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