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Saturday, 31 October

JEE Main · Chemistry · Environmental Chemistry

Fluoride Limits in Drinking Water

JEE Main asked Fluoride Limits in Drinking Water 3 times in 3 of the 108 shifts Lumi analysed, in 2017, 2021 and 2022. It belongs to Environmental Chemistry (Chemistry). The longest wait between two years asking it was 4 years, across 2018 and 2019, which Lumi has no shifts for.

Updated 2026-10-24

Times asked
3
in 3 shifts
Years
3 of 8
First asked
2017
last in 2022
Pattern
Comes in cycles
across the analysed shifts

Questions on this idea a shift, by year

2017–2026. Asked in 2017, 2021 and 2022. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift of 25 Chemistry questions.

00.510.83’170’200.03’210.03’220’230’240’250’26

Raw count: 2017: 1 in 1 shift · 2020: 0 in 12 shifts · 2021: 1 in 24 shifts · 2022: 1 in 24 shifts · 2023: 0 in 12 shifts · 2024: 0 in 18 shifts · 2025: 0 in 8 shifts · 2026: 0 in 9 shifts.

Shift by shift

Each square is one analysed shift, in date order. Open a filled one for that paper.

  • 20260 of 9
  • 20250 of 8
  • 20240 of 18
  • 20230 of 12
  • 20221 of 24
  • 20211 of 24
  • 20200 of 12
  • 20171 of 1

Asked in that shift More than once Not asked

How JEE Main framed it

Assertion–reason is the usual form. Skill tested: recall.

  • Assertion-reason on environmental chemistry
  • Identify pollutant exceeding drinking water limit

Difficulty

Easy 2Medium 1Hard 0

Every question was multiple choice.

Every question

All 3 questions

From the official JEE Main shift papers, newest first. Open one for the full question, the options and the official answer.

  1. 27 Jul 2022, Shift 1 · Q73Match List I with List II. List I (Pollutant) | List II (Disease/sickness) A. Sulphate (>500 ppm) | I. Methemoglobinemia B. Nitrate (>50…MediumMatch the list
  2. 3 Aug 2021, Shift 2 · Q41Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R Assertion A : Fluoride ion…EasyAssertion–reason
  3. 2 Apr 2017 (offline) · Q44A water sample has ppm level concentration of following anions F−=10\mathrm{F^-}=10 ; SO42−=100\mathrm{SO_4^{2-}}=100 ; NO3−=50\mathrm{NO_3^-}=50 The…EasySingle correct

Shifts: 2 Apr 2017 (offline), 3 Aug 2021, Shift 2, 27 Jul 2022, Shift 1.

Same topic

Other ideas in Environmental Chemistry

Environmental Chemistry has 19 ideas JEE Main has asked; 15 of them came up in more than one question. The 12 most asked are below.

Topic analysisChapter analysisAll repeated ideas