JEE Main · Chemistry · Organic Chemistry: Some Basic Principles and Techniques
Anion Analysis: JEE Main previous year questions
19 questions in the 108 JEE Main shifts Lumi analysed, in 7 of 8 years. Pattern: Asked most years. 7 came in 2024–26. Here is how it is asked and which ideas come back.
- Questions
- 19
- in 18 of 108 shifts
- Years asked
- 7/8
- last asked 2026
- Weighted estimate
- 0.1
- model; history: 0.2 a shift on average, typically 0.1–0.2
Key findings
- 01
Asked in 7 of 8 years with analysed shifts and in 18 of 108 shifts: 19 questions, #145 of 196 topics. The years that asked it were 1.5 apart on average.
- 02
72% of its questions since 2020 tested an idea no earlier year had asked; 2 repeated an idea from the year before.
- 03
The most repeated idea is Sulfide Sodium Nitroprusside Test, asked 4 times in 4 shifts (2021, 2022, 2025), most often as “identify ion from colour test”.
- 04
JEE Main has asked 13 of the 43 ideas in this topic; 25 have never been asked, directly or inside another question.
- 05
Mostly asked as single correct (79%); 5% need a numerical answer, 68% are easy and 0% hard.
- 06
The skill tested most is recall (68%), then application (16%).
Questions a shift, year by year
Out of the 25 Chemistry questions in a shift. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift.
Raw count: 2017: 1 in 1 shift · 2020: 0 in 12 shifts · 2021: 5 in 24 shifts · 2022: 5 in 24 shifts · 2023: 1 in 12 shifts · 2024: 5 in 18 shifts · 2025: 1 in 8 shifts · 2026: 1 in 9 shifts.
- Up to 2023
- 0.3
- a shift, of 25
- Since 2024
- 0.2
- -0.1
- Usual gap
- 1.5 yrs
- between years asking it
- Shifts with it
- 18/108
- 17% of analysed shifts
How it is asked
Difficulty, format and skill
Across all 19 questions on Anion Analysis since 2017.
Difficulty
QUESTIONS- Easy13 · 68%
- Medium6 · 32%
- Hard0 · 0%
Format
SHARE- Single correct · 15 Q79%
- Match the list · 2 Q11%
- Numerical value · 1 Q5%
- Two statements · 1 Q5%
Skill tested
SHARE- Recall · 13 Q68%
- Application · 3 Q16%
- Multi-step · 2 Q11%
- Conceptual · 1 Q5%
Repeats
New idea, or one asked before?
Each column is a year. Blue questions tested an idea no earlier year had asked; navy ones went back to an idea from an earlier year. 2017 is the first year, so everything in it counts as new. Heights are question counts, and Lumi analysed 1 to 24 shifts a year, so compare the split inside a column rather than heights across years.
- Idea asked for the first time
- Idea asked in an earlier year
Coverage of the topic
JEE Main has asked 13 of the 43 ideas in this topic. 25 have never been asked yet.
- Asked directly13 · 30%
- Touched inside another question5 · 12%
- Never asked25 · 58%
Ideas come from Lumi’s JEE syllabus map. A never-asked idea is not a safe skip: across all of JEE Main, 22% of questions since 2024 tested an idea no earlier year had asked.
Drill down
Chapter, idea, question
Every idea JEE Main tested in this topic, with its eight years. Open one to read the questions.
6 ideas inside
Squares are the 8 years with analysed shifts, 2017 to 2026. A number is the questions that year when there is more than one; the shade is scaled to one shift, so a year with more analysed shifts (1 to 24 a year) does not look darker. Share is of the level above.
Ideas
Every idea inside this topic
13 different ideas were tested; 4 came more than once.
identify ion from colour test
Single correct · 4 shiftsreagent identification
Single correct · 2 shiftsidentify products of a named test
Match the list · 2 shiftsidentify anions from test observations
Single correct · 2 shiftsoxidation state in test product
Single correct · 1 shiftmolar mass of salt giving no coloured vapour
Numerical value · 1 shift · 1 numericalidentify anion from precipitate test
Single correct · 1 shiftstatement i/ii on qualitative test for anion
Two statements · 1 shiftmatch list on anions and gases evolved
Match the list · 1 shiftstatement not true for nitrate test
Single correct · 1 shiftidentify anion from barium chloride test and gas
Single correct · 1 shiftproducts formed in sequence from reagent
Single correct · 1 shiftidentify compound from test observations
Single correct · 1 shift
| Idea | Years asked | Times | Shifts | Format | Numerical |
|---|---|---|---|---|---|
| Sulfide Sodium Nitroprusside Testidentify ion from colour test | 4 | 4 | Single correctRecall | – | |
| Sulfite Dichromate Paper Testreagent identification | 2 | 2 | Single correctRecall | – | |
| Cyanide Prussian Blue Testidentify products of a named test | 2 | 2 | Match the listRecall | – | |
| Acetate Neutral FeCl3 Testidentify anions from test observations | 2 | 2 | Single correctApplication | – | |
| Chromate Hydrogen Peroxide Testoxidation state in test product | 1 | 1 | Single correctApplication | – | |
| Conc Acid Group Identificationmolar mass of salt giving no coloured vapour | 1 | 1 | Numerical valueMulti-step | 1 | |
| Halide Confirmatory Testsidentify anion from precipitate test | 1 | 1 | Single correctRecall | – | |
| Sulfide Lead Acetate Teststatement i/ii on qualitative test for anion | 1 | 1 | Two statementsConceptual | – | |
| Dilute Acid Group Identificationmatch list on anions and gases evolved | 1 | 1 | Match the listRecall | – | |
| Nitrate Brown Ring Teststatement not true for nitrate test | 1 | 1 | Single correctRecall | – | |
| Sulfate vs Sulfite Barium Testidentify anion from barium chloride test and gas | 1 | 1 | Single correctApplication | – | |
| Carbonate Lime Water Testproducts formed in sequence from reagent | 1 | 1 | Single correctRecall | – | |
| Oxalate Calcium Chloride Testidentify compound from test observations | 1 | 1 | Single correctMulti-step | – |
Times and shifts count every analysed shift. Across JEE Main, 78% of questions since 2024 went back to an idea an earlier year had asked; the rest were new. All repeated ideas
Every question
Anion Analysis questions, year by year
The opening words of each question as it appeared in the official paper, with the idea it tested. Open one for its options and the official answer.
JEE Main 20261 question in 1 shift
- 5 Apr, Shift 2Q70A paper dipped in a dil. solution of 'X' upon treatment with gas turns into green. The compound 'X' is :
Idea: Sulfite Dichromate Paper Test
EasySingle correct
JEE Main 20251 question in 1 shift
- 2 Apr, Shift 2Q62Formation of , a purple coloured complex formed by addition of sodium nitroprusside in sodium carbonate…
Idea: Sulfide Sodium Nitroprusside Test
EasySingle correct
JEE Main 20245 questions in 5 shifts
- 6 Apr, Shift 2Q72During the detection of acidic radical present in a salt, a student gets a pale yellow precipitate soluble with difficulty in…
Idea: Halide Confirmatory Tests
New ideaEasySingle correct - 8 Apr, Shift 1Q73Match List I with List II LIST I (Compound): A. ; B. ; C.…
Idea: Cyanide Prussian Blue Test
MediumMatch the list - 29 Jan, Shift 1Q79In chromyl chloride test for confirmation of ion, a yellow solution is obtained. Acidification of the solution and…
Idea: Chromate Hydrogen Peroxide Test
New ideaMediumSingle correct - 30 Jan, Shift 1Q79Given below are two statements : Statement (I) : The gas liberated on warming a salt with dil , turns a piece of paper…
Idea: Sulfide Lead Acetate Test
New ideaEasyTwo statements - 31 Jan, Shift 1Q90Molar mass of the salt from , , and which does not evolve coloured vapours…
Idea: Conc Acid Group Identification
New ideaEasyNumerical value
JEE Main 20231 question in 1 shift
- 11 Apr, Shift 1Q80When a solution of mixture having two inorganic salts was treated with freshly prepared ferrous sulphate in acidic medium, a dark brown…
Idea: Acetate Neutral FeCl3 Test
Asked the year beforeEasySingle correct
JEE Main 20225 questions in 5 shifts
- 26 Jun, Shift 1Q80Which statement is not true with respect to nitrate ion test ?
Idea: Nitrate Brown Ring Test
New ideaEasySingle correct - 27 Jun, Shift 2Q80Match List I with List II. List I (Anion) | List II (gas evolved on reaction with dil.) A. | I.…
Idea: Dilute Acid Group Identification
New ideaMediumMatch the list - 28 Jun, Shift 1Q80The formula of the purple colour formed in Laissaigne’s test for sulphur using sodium nitroprusside is
Idea: Sulfide Sodium Nitroprusside Test
Asked the year beforeEasySingle correct - 29 Jun, Shift 2Q80A white precipitate was formed when was added to water extract of an inorganic salt. Further, a gas ‘X’ with…
Idea: Sulfate vs Sulfite Barium Test
New ideaEasySingle correct - 30 Jun, Shift 1Q80The reagent neutral ferric chloride is used to detect the presence of ___________
Idea: Acetate Neutral FeCl3 Test
New ideaEasySingle correct
JEE Main 20215 questions in 4 shifts
- 3 Aug, Shift 2Q42In the detection of nitrogen in an organic compound by Lassaigne's test, the iron compounds formed are
Idea: Cyanide Prussian Blue Test
New ideaMediumSingle correct - 4 Aug, Shift 2Q50The reagent that gives purple coloured complex with ion is
Idea: Sulfide Sodium Nitroprusside Test
New ideaEasySingle correct - 26 Aug, Shift 1Q37What are the products formed in sequence when excess of is passed in slaked lime ?
Idea: Carbonate Lime Water Test
New ideaEasySingle correct - 26 Aug, Shift 1Q41Which one of the following complexes is violet in colour ?
Idea: Sulfide Sodium Nitroprusside Test
New ideaMediumSingle correct - 26 Feb, Shift 1Q50On treating a compound with warm dil. , gas X is evolved which turns paper acidified with dil.…
Idea: Sulfite Dichromate Paper Test
New ideaEasySingle correct
JEE Main 20171 question in 1 shift
- 2 Apr (offline)Q48Sodium salt of an organic acid 'X' produces effervescence with conc. . 'X' reacts with the acidified aqueous…
Idea: Oxalate Calcium Chloride Test
MediumSingle correct
Questions from the official JEE Main Paper 1 shifts published by NTA (CBSE for 2017). Questions NTA dropped are left out. Topic and idea tags, counts and notes are Lumi’s.