NEET UG · Chemistry · Redox Reactions

Redox Reactions: NEET previous year questions

10 questions in ten years of NEET, in 8 of 10 papers. Pattern: Every year. Here is how it is asked and which ideas come back.

Asked in 10 years: 10; about 1.0 per paper
Years asked: 8/10; last asked 2026
Chance of a question next paper: 64%; historical rate, how we compute it
Weighted estimate: 1.1; model; history: 1.0 a paper on average, typically 0–2

Key findings

01
Asked in 8 of 10 papers, 10 questions in all: #74 of 204 topics by ten-year total. It comes back every 1.1 years on average.
02
50% 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 Calculating Oxidation Numbers, asked 4 times (2018, 2020, 2025, 2026), usually as “order of oxidation states”.
04
NEET has asked 0 of the 5 ideas in this topic; 0 have never been asked, directly or indirectly.
05
Mostly asked as one-line MCQ (80%); 50% easy, 0% hard, and up from 0.8 to 1.3 questions a paper since 2024.

Questions per year

Up to 2023: 0.8; per paper
Since 2024: 1.3; +0.5
Usual gap: 1.1 yrs; between papers asking it
Swing: ±0.6; questions, year to year

How it is asked

Difficulty, format and skill

Across all 10 questions on Redox Reactions since 2017.

Difficulty

QUESTIONS

Easy5 · 50%
Medium5 · 50%
Hard0 · 0%

Format

One-line MCQ · 8 Q80%
Numerical · 1 Q10%
Other · 1 Q10%

Skill tested

Calculation · 6 Q60%
Application · 2 Q20%
Recall · 1 Q10%
Multi-step · 1 Q10%

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 0 of the 5 ideas in this topic. 0 have never been asked yet.

Asked directly0 · 0%
Touched inside another question5 · 100%
Never asked0 · 0%

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

Repeated4 · 40%40%4/10
- 2026 · Q81
  The correct decreasing order of oxidation state of the underlined atom in each molecule is
  mediumOne-line MCQAsked the year before
- 2025 · Q55
  Consider the following compounds : $\underline{K}O_2$ , $H_2\underline{O}_2$ and $H_2\underline{S}O_4$ The oxidation states of the…
  easyOne-line MCQ
- 2020 · Q125
  What is the change in oxidation number of carbon in the following reaction ? $\mathrm{CH_4(g) + 4Cl_2(g) \to CCl_4(l) + 4HCl(g)}$
  easyOne-line MCQ
- 2018 · Q46
  The correct order of N-compounds in its decreasing order of oxidation states is
  easyOne-line MCQNew idea
Repeated3 · 30%30%3/10
1 · 10%10%1/10
1 · 10%10%1/10
1 · 10%10%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

5 different ideas were tested; 2 came more than once.

Calculating Oxidation Numbers4×
order of oxidation states
One-line MCQ · 11% next
Balancing Redox Equations3×
balance redox reaction coefficients
One-line MCQ · 11% next
Identifying Redox Reactions1×
identify reaction not of a type
One-line MCQ · 6% next
Types of Redox Reactions1×
identify reaction type among options
One-line MCQ · 4% next
Disproportionation Reactions1×
identify reactions of a given type
Other · 4% next

Idea	Times	Format	Chance next	Foundation for
Calculating Oxidation Numbersorder of oxidation states	4	One-line MCQCalculation	11%	–
Balancing Redox Equationsbalance redox reaction coefficients	3	One-line MCQCalculation	11%	–
Identifying Redox Reactionsidentify reaction not of a type	1	One-line MCQApplication	6%	–
Types of Redox Reactionsidentify reaction type among options	1	One-line MCQRecall	4%	–
Disproportionation Reactionsidentify reactions of a given type	1	OtherApplication	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

Redox Reactions questions, year by year

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

NEET 20262 questions

Q57
In an acidic medium, 10 mL of 0.25 M oxalic acid is titrated with $\mathrm{KMnO_4}$ solution. If the volume of $\mathrm{KMnO_4}$ solution…
Idea: Balancing Redox Equations
MediumNumerical
Q81
The correct decreasing order of oxidation state of the underlined atom in each molecule is
Idea: Calculating Oxidation Numbers
Asked last yearMediumOne-line MCQ

NEET 20251 question

Q55
Consider the following compounds : $\underline{K}O_2$ , $H_2\underline{O}_2$ and $H_2\underline{S}O_4$ The oxidation states of the…
Idea: Calculating Oxidation Numbers
EasyOne-line MCQ

NEET 20241 question

Q73
Which reaction is NOT a redox reaction?
Idea: Identifying Redox Reactions
New ideaEasyOne-line MCQ

NEET 20231 question

Q100
On balancing the given redox reaction,…
Idea: Balancing Redox Equations
MediumOne-line MCQ

NEET 20211 question

Q52
Which of the following reactions is the metal displacement reaction ? Choose the right option.
Idea: Types of Redox Reactions
New ideaEasyOne-line MCQ

NEET 20201 question

Q125
What is the change in oxidation number of carbon in the following reaction ? $\mathrm{CH_4(g) + 4Cl_2(g) \to CCl_4(l) + 4HCl(g)}$
Idea: Calculating Oxidation Numbers
EasyOne-line MCQ

NEET 20191 question

Q50
Which of the following reactions are disproportionation reaction ? (a) $2Cu^+ \to Cu^{2+} + Cu^0$ (b)…
Idea: Disproportionation Reactions
New ideaMediumOther

NEET 20182 questions

Q46
The correct order of N-compounds in its decreasing order of oxidation states is
Idea: Calculating Oxidation Numbers
New ideaEasyOne-line MCQ
Q82
For the redox reaction $\mathrm{MnO_4^- + C_2O_4^{2-} + H^+ \longrightarrow Mn^{2+} + CO_2 + H_2O}$ the correct coefficients of the…
Idea: Balancing Redox Equations
New ideaMediumOne-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.