JEE Main 2024 · ChemistryNumerical answerNumerical valueEasyCalculation

JEE Main 8 April 2024, Shift 2, Chemistry Q84

Question 84 of 90 in this shift, Chemistry question 24 of 30, Section B.

\Delta_{vap}H^{\ominus}

for water is

+40.79\ \mathrm{kJ\,mol^{-1}}

at 1 bar and 100 °C. Change in internal energy for this vapourisation under same condition is ________

\mathrm{kJ\,mol^{-1}}

. (Integer answer) (Given

R = 8.3\ \mathrm{JK^{-1}\,mol^{-1}}

)

Official answer

NTA final key.

Chapter: Thermodynamics (Chemistry)
Topic: Enthalpy and Hess's Law
Idea tested: Relation Between ΔH and ΔU

Same idea in other shifts

Asked 10× in all

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26 Aug 2021, Shift 2 · Q53For water $\Delta_{\mathrm{vap}}H$ = 41 kJ $\mathrm{mol^{-1}}$ at 373 K and 1 bar pressure. Assuming that water vapour is an ideal gas…MediumNumerical value
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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.