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Saturday, 31 October

JEE Main · Chemistry · Organic Chemistry: Some Basic Principles and Techniques

Empirical Formula from Combustion Data

JEE Main asked Empirical Formula from Combustion Data 8 times in 8 of the 108 shifts Lumi analysed, in 2021, 2022, 2023 and 2025. It belongs to Stoichiometry, in Organic Chemistry: Some Basic Principles and Techniques (Chemistry). The longest wait between two years asking it was 2 years. In 2022, 2023 and 2025 it came in more than one shift of the same year.

Updated 2026-10-24

Times asked
8
in 8 shifts
Years
4 of 8
First asked
2021
last in 2025
Pattern
Comes in cycles
across the analysed shifts

Questions on this idea a shift, by year

2017–2026. Asked in 2021, 2022, 2023 and 2025. Years differ in how many shifts Lumi analysed, so each year is scaled to one shift of 25 Chemistry questions.

00.20.40’170’200.03’210.07’220.14’230’240.38’250’26

Raw count: 2017: 0 in 1 shift · 2020: 0 in 12 shifts · 2021: 1 in 24 shifts · 2022: 2 in 24 shifts · 2023: 2 in 12 shifts · 2024: 0 in 18 shifts · 2025: 3 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
  • 20253 of 8
  • 20240 of 18
  • 20232 of 12
  • 20222 of 24
  • 20211 of 24
  • 20200 of 12
  • 20170 of 1

Asked in that shift More than once Not asked

How JEE Main framed it

Numerical value is the usual form. Skill tested: calculation.

  • Percentages from combustion analysis
  • Empirical formula mass from combustion data

Difficulty

Easy 6Medium 2Hard 0

5 of the 8 questions had a numerical answer.

Every question

All 8 questions

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

  1. 8 Apr 2025, Shift 2 · Q62On combustion 0.210 g of an organic compound containing C, H and O gave 0.127 g H2O\mathrm{H_2O} and 0.307 g CO2\mathrm{CO_2}. The…MediumSingle correct
  2. 3 Apr 2025, Shift 1 · Q740.5 g of an organic compound on combustion gave 1.46 g of CO2\mathrm{CO_2} and 0.9 g of H2O\mathrm{H_2O}. The percentage of carbon in the…EasyNumerical value
  3. 2 Apr 2025, Shift 1 · Q63On complete combustion 1.0 g of an organic compound (X) gave 1.46 g of CO2\mathrm{CO_2} and 0.567 g of H2O\mathrm{H_2O}. The empirical…MediumSingle correct
  4. 13 Apr 2023, Shift 1 · Q88An organic compound gives 0.220 g of CO2\mathrm{CO_2} and 0.126 g of H2O\mathrm{H_2O} on complete combustion. If the % of carbon is 24 then…EasyNumerical value
  5. 8 Apr 2023, Shift 1 · Q900.5 g of an organic compound (X) with 60% carbon will produce ______ ×10−1\times10^{-1} g of CO2\mathrm{CO_2} on complete combustion.EasyNumerical value
  6. 26 Jun 2022, Shift 1 · Q88On complete combustion 0.30 g of an organic compound gave 0.20 g of carbon dioxide and 0.10 g of water. The percentage of carbon in the…EasyNumerical value
  7. 28 Jul 2022, Shift 1 · Q90On complete combustion of 0.492 g of an organic compound containing C, H and O, 0.7938 g of CO2\mathrm{CO_2} and 0.4428 g of…EasyNumerical value
  8. 25 Feb 2021, Shift 1 · Q42Complete combustion of 1.80 g of an oxygen containing compound (CxHyOz\mathrm{C_xH_yO_z}) gave 2.64 g of CO2\mathrm{CO_2} and 1.08 g of…EasySingle correct

Shifts: 25 Feb 2021, Shift 1, 26 Jun 2022, Shift 1, 28 Jul 2022, Shift 1, 8 Apr 2023, Shift 1, 13 Apr 2023, Shift 1, 2 Apr 2025, Shift 1, 3 Apr 2025, Shift 1, 8 Apr 2025, Shift 2.

Same topic

Other ideas in Stoichiometry

Stoichiometry has 24 ideas JEE Main has asked; 13 of them came up in more than one question. The 12 most asked are below.

Topic analysisChapter analysisStudy this chapterAll repeated ideas