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JEE Main 2 September 2020, Shift 2, Chemistry Q47

Question 47 of 75 in this shift, Chemistry question 22 of 25.

The heat of combustion of ethanol into carbon dioxids and water is

-327

kcal at constant pressure. The heat evolved (in cal) at constant volume and

27^\circ

C (if all gases behave ideally) is (

R=2

cal

\mathrm{mol^{-1}}

\mathrm{K^{-1}}

) __________.

Official answer

-326400.00

NTA final key (Sep 2020).

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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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.