JEE Main 2022 · ChemistryNumerical answerNumerical valueEasyCalculation

JEE Main 28 July 2022, Shift 1, Chemistry Q90

Question 90 of 90 in this shift, Chemistry question 30 of 30, Section B.

On complete combustion of 0.492 g of an organic compound containing C, H and O, 0.7938 g of

\mathrm{CO_2}

and 0.4428 g of

\mathrm{H_2O}

was produced. The % composition of oxygen in the compound is __________.

Official answer

NTA final key (2022 Session 2).

Chapter: Organic Chemistry: Some Basic Principles and Techniques
Topic: Stoichiometry
Idea tested: Empirical Formula from Combustion Data

Same idea in other shifts

Asked 4× in all

2 Apr 2025, Shift 1 · Q63On complete combustion 1.0 g of an organic compound (X) gave 1.46 g of $\mathrm{CO_2}$ and 0.567 g of $\mathrm{H_2O}$ . The empirical…MediumSingle correct
3 Apr 2025, Shift 1 · Q740.5 g of an organic compound on combustion gave 1.46 g of $\mathrm{CO_2}$ and 0.9 g of $\mathrm{H_2O}$ . The percentage of carbon in the…EasyNumerical value
8 Apr 2025, Shift 2 · Q62On combustion 0.210 g of an organic compound containing C, H and O gave 0.127 g $\mathrm{H_2O}$ and 0.307 g $\mathrm{CO_2}$ . The…MediumSingle correct

Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 42 of the 174 JEE Main shifts held from 2017 to 2026.