JEE Main 2021 · ChemistryNumerical answerNumerical valueEasyCalculation

JEE Main 26 February 2021, Shift 1, Chemistry Q53

Question 53 of 90 in this shift, Chemistry question 23 of 30, Section B.

For a chemical reaction

\mathrm{A + B \rightleftharpoons C + D}

(

\Delta_r H^{\ominus} = 80

kJ mol

^{-1}

) the entropy change

\Delta_r S^{\ominus}

depends on the temperature T(in K) as

\Delta_r S^{\ominus} = 2T

(J K

^{-1}

mol

^{-1}

). Minimum temperature at which it will become spontaneous is __________ K. (Integer)

Official answer

200

NTA final key.

Chapter: Thermodynamics (Chemistry)
Topic: Gibbs Free Energy
Idea tested: Temperature Dependence

Same idea in other shifts

Asked 3× in all

6 Apr 2024, Shift 2 · Q83For the reaction at 298 K, $2A + B \rightarrow C$ , $\Delta H = 400$ kJ mol $^{-1}$ and $\Delta S = 0.2$ kJ mol $^{-1}$ K $^{-1}$ . The…EasyNumerical value
27 Aug 2021, Shift 2 · Q55Data given for the following reaction is as follows : $\mathrm{FeO_{(s)} + C_{(graphite)} \longrightarrow Fe_{(s)} + CO_{(g)}}$ Table…MediumNumerical valueHas a figure

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.