JEE Main 2020ChemistryThermodynamics (C)MediumNumerical

JEE Main 2020 — Thermodynamics (C) Question with Solution

JEE Main 2020 (07 Jan Shift 2)

Question

The standard heat of formation ∆fH2980 of ethane (in kJ/mol ), if the heat of combustion of ethane, hydrogen and graphite are -1560,-393.5 and -286 kJ/mol , respectively is ________

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Show full solutionCorrect answer: -192
Correct answer
-192

Step-by-step explanation

2C( graphite )+3 H 2 (g)→ C 2 H 6 (g)

Δ f H C 2 H 6 =2Δ H comb  C gaphite  +3Δ H comb  H 2

−Δ H comb  C 2 H 6

=−(286×2)−(393.5×3)−(−1560)

=−572−1180.5+1560=−192.5 kJ/mole

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About this question

This is a previous-year question from JEE Main 2020, 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.