JEE Main 2026 · ChemistryNumerical answerNumerical valueMediumCalculation

JEE Main 6 April 2026, Shift 1, Chemistry Q75

Question 75 of 75 in this shift, Chemistry question 25 of 25, Section B.

Consider the reaction

\mathrm{X\rightleftharpoons Y}

at 300 K. If

\Delta H^\theta

and K are 28.40 kJ mol

^{-1}

and

1.8\times10^{-7}

at the same temperature, then the magnitude of

\Delta S^\theta

for the reaction in J K

^{-1}

mol

^{-1}

is________. (Nearest integer) (Given : R = 8.3 J K

^{-1}

mol

^{-1}

, ln 10 = 2.3, log 3 = 0.48, log 2 = 0.30)

Official answer

NTA final key.

Chapter: Thermodynamics (Chemistry)
Topic: Gibbs Free Energy
Idea tested: Gibbs Energy and Equil

Same idea in other shifts

Asked 5× in all

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31 Jan 2024, Shift 1 · Q84Consider the following reaction at 298 K. $\frac{3}{2}\mathrm{O_{2(g)}} \rightleftharpoons \mathrm{O_{3(g)}}$ .…EasyNumerical value
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24 Jun 2022, Shift 1 · Q82 $\mathrm{2O_3(g)\rightleftharpoons 3O_2(g)}$ At 300 K, ozone is fifty percent dissociated. The standard free energy change at this…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 42 of the 174 JEE Main shifts held from 2017 to 2026.