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Saturday, 31 October

JEE Main 2021 · ChemistryNumerical answerNumerical valueEasyCalculation

JEE Main 17 March 2021, Shift 1, Chemistry Q54

Question 54 of 90 in this shift, Chemistry question 24 of 30, Section B.

The standard enthalpies of formation of Al2O3\mathrm{Al_2O_3} and CaO are −1675 kJ mol−1-1675\ \mathrm{kJ\ mol^{-1}} and −635 kJ mol−1-635\ \mathrm{kJ\ mol^{-1}} respectively. For the reaction 3CaO+2Al→3Ca+Al2O3\mathrm{3CaO + 2Al \rightarrow 3Ca + Al_2O_3} the standard reaction enthalpy ΔrH0=\Delta_r H^0 = __________ kJ. (Round off to the Nearest Integer).

Official answer

230

NTA final key.

Same idea in other shifts

Asked 2× in all
  1. 11 Apr 2023, Shift 1 · Q83Solid fuel used in rocket is a mixture of Fe2O3\mathrm{Fe_2O_3} and Al (in ratio 1:2). The heat evolved (kJ) per gram of the mixture is…MediumNumerical 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.