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Saturday, 31 October

JEE Main 2022 · ChemistryNumerical answerNumerical valueMediumMulti-step

JEE Main 28 June 2022, Shift 1, Chemistry Q81

Question 81 of 90 in this shift, Chemistry question 21 of 30, Section B.

A 2.0 g sample containing MnO2\mathrm{MnO_2} is treated with HCl liberating Cl2\mathrm{Cl_2}. The Cl2\mathrm{Cl_2} gas is passed into a solution of KI and 60.0 mL of 0.1 M Na2S2O3\mathrm{Na_2S_2O_3} is required to titrate the liberated iodine. The percentage of MnO2\mathrm{MnO_2} in the sample is ________ (Nearest integer) [Atomic masses (in u) Mn = 55; Cl = 35.5; O = 16, I = 127, Na = 23, K = 39, S = 32]

Official answer

13

NTA final key.

Chapter
Some Basic Concepts of Chemistry
Topic
Redox Reactions
Idea tested
Thiosulfate-Iodine Reaction Stoichiometry

Same idea in other shifts

Asked 2× in all
  1. 8 Apr 2024, Shift 1 · Q64Thiosulphate reacts differently with iodine and bromine in the reactions given below:…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 108 of the 174 JEE Main shifts held from 2017 to 2026.