NEET UG · Chemistry · Hydrocarbons

Hydrocarbons (Alkanes): NEET previous year questions

9 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: 9; about 0.9 per paper
Years asked: 7/10; last asked 2025
Chance of a question next paper: 64%; historical rate, how we compute it
Weighted estimate: 0.8; model; history: 0.9 a paper on average, typically 0–2

Key findings

01
Asked in 7 of 10 papers, 9 questions in all: #91 of 204 topics by ten-year total. It comes back every 1.3 years on average. Last asked in 2025.
02
75% 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 Soda Lime Decarboxylation, asked 2 times (2021, 2023), usually as “numerical”.
04
NEET has asked 7 of the 68 ideas in this topic; 57 have never been asked, directly or indirectly.
05
Mostly asked as one-line MCQ (78%); 56% easy, 0% hard.

Questions per year

Up to 2023: 0.8; per paper
Since 2024: 1.0; 0.2
Usual gap: 1.3 yrs; between papers asking it
Swing: ±0.7; questions, year to year

How it is asked

Difficulty, format and skill

Across all 9 questions on Hydrocarbons (Alkanes) since 2017.

Difficulty

QUESTIONS

Easy5 · 56%
Medium4 · 44%
Hard0 · 0%

Format

One-line MCQ · 7 Q78%
Two statements · 1 Q11%
Numerical · 1 Q11%

Skill tested

Recall · 3 Q33%
Application · 3 Q33%
Concept · 2 Q22%
Multi-step · 1 Q11%

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 7 of the 68 ideas in this topic. 57 have never been asked yet.

757

Asked directly7 · 10%
Touched inside another question4 · 6%
Never asked57 · 84%

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 · 22%22%2/10
- 2023 · Q68
  Weight (g) of two moles of the organic compound, which is obtained by heating sodium ethanoate with sodium hydroxide in presence of…
  easyNumerical
- 2021 · Q99
  $\mathrm{CH_3CH_2COO^{-}Na^{+} \xrightarrow[Heat]{NaOH,\ +\ ?} CH_3CH_3 + Na_2CO_3}$ . Consider the above reaction and identify the missing…
  easyOne-line MCQNew idea
Repeated2 · 22%22%2/10
1 · 11%11%1/10
1 · 11%11%1/10
1 · 11%11%1/10
1 · 11%11%1/10
1 · 11%11%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

7 different ideas were tested; 2 came more than once. Conformational Analysis is the foundation for 8 other ideas in the syllabus.

Soda Lime Decarboxylation2×
numerical
Numerical · 6% next · foundation for 2
Wurtz Reaction Mechanism2×
identify hydrocarbon from reaction sequence
One-line MCQ · 4% next · foundation for 3
Aromatization (Reforming)1×
identify reaction not giving given product
One-line MCQ · 6% next
Free Radical Halogenation1×
count products of monohalogenation
One-line MCQ · 6% next · foundation for 7
Boiling Point Trends1×
statement i/ii on boiling point trends
Two statements · 6% next · foundation for 2
Conformational Dihedral Angles1×
identify dihedral angle of conformer
One-line MCQ · 4% next
Conformational Analysis1×
true statement selection on conformers
One-line MCQ · 4% next · foundation for 8

Idea	Times	Format	Chance next	Foundation for
Soda Lime Decarboxylationnumerical	2	NumericalMulti-step	6%	2 ideas
Wurtz Reaction Mechanismidentify hydrocarbon from reaction sequence	2	One-line MCQApplication	4%	3 ideas
Aromatization (Reforming)identify reaction not giving given product	1	One-line MCQRecall	6%	–
Free Radical Halogenationcount products of monohalogenation	1	One-line MCQApplication	6%	7 ideas
Boiling Point Trendsstatement i/ii on boiling point trends	1	Two statementsConcept	6%	2 ideas
Conformational Dihedral Anglesidentify dihedral angle of conformer	1	One-line MCQRecall	4%	–
Conformational Analysistrue statement selection on conformers	1	One-line MCQConcept	4%	8 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

Hydrocarbons (Alkanes) questions, year by year

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

NEET 20252 questions

Q60
Which one of the following reactions does NOT give benzene as the product ?
Idea: Aromatization (Reforming)
New ideaMediumOne-line MCQ · figure
Q75
How many products (including stereoisomers) are expected from monochlorination of the following compound? $(CH_3)_2CH-CH_2-CH_3$
Idea: Free Radical Halogenation
New ideaMediumOne-line MCQ · figure

NEET 20241 question

Q76
Given below are two statements: Statement I : The boiling point of three isomeric pentanes follows the order n-pentane > isopentane >…
Idea: Boiling Point Trends
New ideaEasyTwo statements

NEET 20231 question

Q68
Weight (g) of two moles of the organic compound, which is obtained by heating sodium ethanoate with sodium hydroxide in presence of…
Idea: Soda Lime Decarboxylation
EasyNumerical

NEET 20212 questions

Q69
Dihedral angle of least stable conformer of ethane is :
Idea: Conformational Dihedral Angles
New ideaEasyOne-line MCQ
Q99
$\mathrm{CH_3CH_2COO^{-}Na^{+} \xrightarrow[Heat]{NaOH,\ +\ ?} CH_3CH_3 + Na_2CO_3}$ . Consider the above reaction and identify the missing…
Idea: Soda Lime Decarboxylation
New ideaEasyOne-line MCQ

NEET 20201 question

Q134
Which of the following alkane cannot be made in good yield by Wurtz reaction ?
Idea: Wurtz Reaction Mechanism
MediumOne-line MCQ

NEET 20181 question

Q62
Hydrocarbon (A) reacts with bromine by substitution to form an alkyl bromide which by Wurtz reaction is converted to gaseous hydrocarbon…
Idea: Wurtz Reaction Mechanism
New ideaMediumOne-line MCQ

NEET 20171 question

Q46
With respect to the conformers of ethane, which of the following statements is true ?
Idea: Conformational Analysis
EasyOne-line MCQ

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