JEE Main 2021ChemistryThermodynamics (C)EasyNumerical

JEE Main 2021 — Thermodynamics (C) Question with Solution

JEE Main 2021 (25 Feb Shift 1)

Question

The reaction of cyanamide, NH2CNs with oxygen was run in a bomb calorimeter and ΔU was found to be -742.24 kJ mol-1 . The magnitude of ΔH298 for the reaction  NH2CNs+32O2g→N2g+O2g+H2Ol is kJ. (Rounded off to the nearest integer) [Assume ideal gases and R=8.314 J mol-1 K-1]

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Show full solutionCorrect answer: 741
Correct answer
741

Step-by-step explanation

ΔH=ΔU+ΔngRT

=-742.24+12×8.3141000×298

=-741 kJ/mol

Hence answer is 741

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About this question

This is a previous-year question from JEE Main 2021, covering the Thermodynamics (C) chapter of Chemistry. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.