JEE Main 2021 · ChemistryMultiple choiceSingle correctEasyCalculation

JEE Main 25 February 2021, Shift 1, Chemistry Q42

Question 42 of 90 in this shift, Chemistry question 12 of 30, Section A.

Complete combustion of 1.80 g of an oxygen containing compound (

\mathrm{C_xH_yO_z}

) gave 2.64 g of

\mathrm{CO_2}

and 1.08 g of

\mathrm{H_2O}

. The percentage of oxygen in the organic compound is :

(1)50.33
(2)53.33Official answer
(3)63.53
(4)51.63

Official answer

Option 2

NTA final key.

Chapter: Some Basic Concepts of Chemistry
Topic: Stoichiometry
Idea tested: Empirical Formula from Combustion Data

Same idea in other shifts

Asked 8× in all

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8 Apr 2023, Shift 1 · Q900.5 g of an organic compound (X) with 60% carbon will produce ______ $\times10^{-1}$ g of $\mathrm{CO_2}$ on complete combustion.EasyNumerical value
13 Apr 2023, Shift 1 · Q88An organic compound gives 0.220 g of $\mathrm{CO_2}$ and 0.126 g of $\mathrm{H_2O}$ on complete combustion. If the % of carbon is 24 then…EasyNumerical value
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 $\mathrm{CO_2}$ and 0.4428 g of…EasyNumerical value
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

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 108 of the 174 JEE Main shifts held from 2017 to 2026.