NEET UG · Chemistry · Hydrocarbons

Hydrocarbons (Alkynes): NEET previous year questions

4 questions in ten years of NEET, in 3 of 10 papers. Pattern: Most years. Here is how it is asked and which ideas come back.

Asked in 10 years: 4; about 0.4 per paper
Years asked: 3/10; last asked 2025
Chance of a question next paper: 37%; historical rate, how we compute it
Weighted estimate: 0.3; model; history: 0.4 a paper on average, typically 0–1

Key findings

01
Asked in 3 of 10 papers, 4 questions in all: #171 of 204 topics by ten-year total. It comes back every 4.0 years on average. Last asked in 2025.
02
100% of its questions since 2018 tested an idea never asked before; none repeated an idea from the year before.
03
No idea in this topic has been asked twice: every question tested something new.
04
NEET has asked 4 of the 85 ideas in this topic; 78 have never been asked, directly or indirectly.
05
Mostly asked as one-line MCQ (75%); 75% easy, 25% hard.

Questions per year

Up to 2023: 0.4; per paper
Since 2024: 0.3; -0.1
Usual gap: 4.0 yrs; between papers asking it
Swing: ±0.7; questions, year to year

How it is asked

Difficulty, format and skill

Across all 4 questions on Hydrocarbons (Alkynes) since 2017.

Difficulty

QUESTIONS

Easy3 · 75%
Medium0 · 0%
Hard1 · 25%

Format

One-line MCQ · 3 Q75%
Figure-based · 1 Q25%

Skill tested

Concept · 2 Q50%
Recall · 1 Q25%
Application · 1 Q25%

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 85 ideas in this topic. 78 have never been asked yet.

Asked directly4 · 5%
Touched inside another question3 · 4%
Never asked78 · 92%

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

1 · 25%25%1/10
- 2017 · Q62
  Which one is the correct order of acidity ?
  easyOne-line MCQNew idea
1 · 25%25%1/10
1 · 25%25%1/10
1 · 25%25%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; none came more than once. Alkyne Structure and Hybridization is the foundation for 25 other ideas in the syllabus.

Alkyne Structure and Hybridization1×
order/ranking of property
Figure-based · 6% next · foundation for 25
Controlled Hydrogenation (Cis/Trans)1×
reagent identification
One-line MCQ · 4% next · foundation for 6
Acidity and s-Character Correlation1×
order/ranking of property
One-line MCQ · 4% next
Hydration and Keto-Enol Tautomerism1×
identify intermediate in reaction sequence
One-line MCQ · 4% next · foundation for 7

Idea	Times	Format	Chance next	Foundation for
Alkyne Structure and Hybridizationorder/ranking of property	1	Figure-basedConcept	6%	25 ideas
Controlled Hydrogenation (Cis/Trans)reagent identification	1	One-line MCQRecall	4%	6 ideas
Acidity and s-Character Correlationorder/ranking of property	1	One-line MCQConcept	4%	–
Hydration and Keto-Enol Tautomerismidentify intermediate in reaction sequence	1	One-line MCQApplication	4%	7 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 (Alkynes) questions, year by year

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

NEET 20251 question

Q76
Among the given compounds I-III, the correct order of bond dissociation energy of C–H bond marked with * is :
Idea: Alkyne Structure and Hybridization
New ideaHardFigure-based · figure

NEET 20191 question

Q55
The most suitable reagent for the following conversion, is : $H_3C-C\equiv C-CH_3 \to$ cis-2-butene
Idea: Controlled Hydrogenation (Cis/Trans)
New ideaEasyOne-line MCQ · figure

NEET 20172 questions

Q57
Predict the correct intermediate and product in the following reaction $\mathrm{H_3C-C\equiv CH \xrightarrow[HgSO_4]{H_2O,\ H_2SO_4}}$ …
Idea: Hydration and Keto-Enol Tautomerism
EasyOne-line MCQ · figure
Q62
Which one is the correct order of acidity ?
Idea: Acidity and s-Character Correlation
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.