NEET UG · Chemistry · Haloalkanes and Haloarenes

Nucleophilic Substitution: NEET previous year questions

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

Asked in 10 years: 16; about 1.5 per paper
Years asked: 10/10; last asked 2026
Chance of a question next paper: 84%; historical rate, how we compute it
Weighted estimate: 1.6; model; history: 1.5 a paper on average, typically 1–3

Key findings

01
Asked in 10 of 10 papers, 16 questions in all: #29 of 204 topics by ten-year total.
02
87% 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 Allylic and Benzylic Reactivity, asked 2 times (2023, 2024), usually as “classify example of a halide type”.
04
NEET has asked 5 of the 80 ideas in this topic; 68 have never been asked, directly or indirectly.
05
Mostly asked as one-line MCQ (88%); 31% easy, 6% hard.

Questions per year

Up to 2023: 1.5; per paper
Since 2024: 1.6; 0.1
Usual gap: 1.0 yrs; between papers asking it
Swing: ±0.7; questions, year to year

Recent framings

predict product of reaction
assertion-reason on leaving group ability
order/ranking of SN1 reactivity

Revise first

Allylic and Benzylic Reactivity (2023 2024); Grignard Reagents (2026); Leaving Group Ability (2025)

How it is asked

Difficulty, format and skill

Across all 16 questions on Nucleophilic Substitution since 2017.

Difficulty

QUESTIONS

510

Easy5 · 31%
Medium10 · 63%
Hard1 · 6%

Format

One-line MCQ · 14 Q88%
Assertion–reason · 1 Q6%
Other · 1 Q6%

Skill tested

Application · 6 Q38%
Concept · 4 Q25%
Recall · 3 Q19%
Multi-step · 3 Q19%

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 5 of the 80 ideas in this topic. 68 have never been asked yet.

Asked directly5 · 6%
Touched inside another question7 · 9%
Never asked68 · 85%

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 · 13%13%2/10
- 2024 · Q58
  The compound that will undergo S $_N$ 1 reaction with the fastest rate is
  mediumOne-line MCQAsked the year before
- 2023 · Q53
  The given compound $\mathrm{C_6H_5{-}CH{=}CH{-}CH(X){-}CH_2CH_3}$ is an example of ________.
  easyOne-line MCQNew idea
Repeated2 · 13%13%2/10
1 · 6%6%1/10
1 · 6%6%1/10
1 · 6%6%1/10
1 · 6%6%1/10
1 · 6%6%1/10
1 · 6%6%1/10
1 · 6%6%1/10
1 · 6%6%1/10
1 · 6%6%1/10
1 · 6%6%1/10
1 · 6%6%1/10
1 · 6%6%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

14 different ideas were tested; 2 came more than once. Stereochemical Outcomes is the foundation for 16 other ideas in the syllabus.

Allylic and Benzylic Reactivity2×
classify example of a halide type
One-line MCQ · 6% next · foundation for 1
Preparation of Haloarenes2×
reagent for synthesis of aryl halide
One-line MCQ · 6% next
Grignard Reagents1×
predict product of reaction
One-line MCQ · 6% next
Leaving Group Ability1×
assertion-reason on leaving group ability
Assertion–reason · 6% next · foundation for 3
Alcohols to Haloalkanes1×
predict product of reaction
One-line MCQ · 6% next
Aqueous vs Alcoholic KOH1×
identify end product of reaction sequence
One-line MCQ · 6% next
Carbocation Rearrangements1×
predict product of reaction
One-line MCQ · 4% next · foundation for 1
Reactions of Haloalkanes and Haloarenes with Metals1×
identify end product of reaction sequence
One-line MCQ · 4% next
Stereochemical Outcomes1×
identify incorrect statement on chirality
One-line MCQ · 4% next · foundation for 16
C-X Bond Enthalpy Trend1×
order/ranking of bond enthalpy
One-line MCQ · 4% next
Saytzeff Rule in Dehydrohalogenation1×
identify rule behind major product
One-line MCQ · 4% next
Dehydrohalogenation and Zaitsev's Rule1×
count correct statements on elimination reaction
Other · 4% next
Side-Chain Halogenation of Toluene1×
predict product of reaction
One-line MCQ · 4% next
Benzyne Elimination-Addition1×
predict product and type of reaction
One-line MCQ · 4% next

Idea	Times	Format	Chance next	Foundation for
Allylic and Benzylic Reactivityclassify example of a halide type	2	One-line MCQApplication	6%	1 ideas
Preparation of Haloarenesreagent for synthesis of aryl halide	2	One-line MCQApplication	6%	–
Grignard Reagentspredict product of reaction	1	One-line MCQApplication	6%	–
Leaving Group Abilityassertion-reason on leaving group ability	1	Assertion–reasonConcept	6%	3 ideas
Alcohols to Haloalkanespredict product of reaction	1	One-line MCQRecall	6%	–
Aqueous vs Alcoholic KOHidentify end product of reaction sequence	1	One-line MCQMulti-step	6%	–
Carbocation Rearrangementspredict product of reaction	1	One-line MCQApplication	4%	1 ideas
Reactions of Haloalkanes and Haloarenes with Metalsidentify end product of reaction sequence	1	One-line MCQMulti-step	4%	–
Stereochemical Outcomesidentify incorrect statement on chirality	1	One-line MCQConcept	4%	16 ideas
C-X Bond Enthalpy Trendorder/ranking of bond enthalpy	1	One-line MCQRecall	4%	–
Saytzeff Rule in Dehydrohalogenationidentify rule behind major product	1	One-line MCQRecall	4%	–
Dehydrohalogenation and Zaitsev's Rulecount correct statements on elimination reaction	1	OtherConcept	4%	–
Side-Chain Halogenation of Toluenepredict product of reaction	1	One-line MCQMulti-step	4%	–
Benzyne Elimination-Additionpredict product and type of reaction	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

Nucleophilic Substitution 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

Q72
One of the products formed in the following reaction is [Cyclohexyl–MgBr + Cyclohexyl– $\mathrm{NH_2}$ $\to$ ]
Idea: Grignard Reagents
New ideaMediumOne-line MCQ · figure

NEET 20251 question

Q84
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) :…
Idea: Leaving Group Ability
New ideaEasyAssertion–reason · figure

NEET 20243 questions

Q58
The compound that will undergo S $_N$ 1 reaction with the fastest rate is
Idea: Allylic and Benzylic Reactivity
Asked last yearMediumOne-line MCQ · figure
Q86
The products A and B obtained in the following reactions, respectively, are 3ROH + PCl $_3$ $\to$ 3RCl + A ROH + PCl $_5$ $\to$ RCl + HCl + B
Idea: Alcohols to Haloalkanes
New ideaMediumOne-line MCQ
Q98
Major products A and B formed in the following reaction sequence, are [2-methylcyclohexan-1-ol] $\xrightarrow{\mathrm{PBr_3}}$ A (major)…
Idea: Aqueous vs Alcoholic KOH
New ideaMediumOne-line MCQ · figure

NEET 20233 questions

Q53
The given compound $\mathrm{C_6H_5{-}CH{=}CH{-}CH(X){-}CH_2CH_3}$ is an example of ________.
Idea: Allylic and Benzylic Reactivity
New ideaEasyOne-line MCQ · figure
Q80
Consider the following reaction and identify the product (P). $\mathrm{CH_3-CH(CH_3)-CH(OH)-CH_3}$ (3-Methylbutan-2-ol)…
Idea: Carbocation Rearrangements
New ideaMediumOne-line MCQ · figure
Q94
Identify the final product [D] obtained in the following sequence of reactions.…
Idea: Reactions of Haloalkanes and Haloarenes with Metals
New ideaMediumOne-line MCQ · figure

NEET 20222 questions

Q58
The incorrect statement regarding chirality is :
Idea: Stereochemical Outcomes
New ideaEasyOne-line MCQ
Q77
Which of the following is suitable to synthesize chlorobenzene ?
Idea: Preparation of Haloarenes
EasyOne-line MCQ · figure

NEET 20212 questions

Q71
The correct sequence of bond enthalpy of 'C–X' bond is :
Idea: C-X Bond Enthalpy Trend
New ideaMediumOne-line MCQ
Q83
The major product formed in dehydrohalogenation reaction of 2-Bromo pentane is Pent-2-ene. This product formation is based on ?
Idea: Saytzeff Rule in Dehydrohalogenation
New ideaEasyOne-line MCQ

NEET 20201 question

Q114
Elimination reaction of 2-Bromo-pentane to form pent-2-ene is : (a) $\beta$ -Elimination reaction (b) Follows Zaitsev rule (c)…
Idea: Dehydrohalogenation and Zaitsev's Rule
New ideaMediumOther

NEET 20191 question

Q65
Among the following, the reaction that proceeds through an electrophilic substitution, is :
Idea: Preparation of Haloarenes
New ideaMediumOne-line MCQ · figure

NEET 20181 question

Q61
The compound $\mathrm{C_7H_8}$ undergoes the following reactions :…
Idea: Side-Chain Halogenation of Toluene
New ideaHardOne-line MCQ

NEET 20171 question

Q80
Identify A and predict the type of reaction [m-bromoanisole (benzene ring with $\mathrm{OCH_3}$ and Br meta to it)] $\xrightarrow{NaNH_2}$ A
Idea: Benzyne Elimination-Addition
MediumOne-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.