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Saturday, 31 October

JEE Main 2023 · ChemistryMultiple choiceSingle correctEasyRecall

JEE Main 15 April 2023, Shift 1, Chemistry Q65

Question 65 of 90 in this shift, Chemistry question 5 of 30, Section A.

Which one of the following is not an example of calcination?
  1. (1)Fe2O3⋅xH2O→ΔFe2O3+xH2O\mathrm{Fe_2O_3 \cdot xH_2O \xrightarrow{\Delta} Fe_2O_3 + xH_2O}
  2. (2)CaCO3→ΔCaO+CO2\mathrm{CaCO_3 \xrightarrow{\Delta} CaO + CO_2}
  3. (3)CaCO3⋅MgCO3→ΔCaO+MgO+2CO2\mathrm{CaCO_3 \cdot MgCO_3 \xrightarrow{\Delta} CaO + MgO + 2CO_2}
  4. (4)2PbS+3O2→Δ2PbO+2SO2\mathrm{2PbS + 3O_2 \xrightarrow{\Delta} 2PbO + 2SO_2}Official answer

Official answer

Option 4

NTA final key.

Chapter
General Principles and Processes of Isolation of Elements
Topic
Metallurgical Extraction
Idea tested
Calcination vs. Roasting

Same idea in other shifts

Asked 3× in all
  1. 4 Aug 2021, Shift 1 · Q36The concentrated ores siderite and copper glance are converted to their oxides byEasySingle correct
  2. 4 Sep 2020, Shift 2 · Q38The processes of calcination and roasting in metallurgical industries, respectively, can lead to :EasySingle 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.