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QJEEM21Chf792: JEE Main 2021 Chemistry - Class 11 JEEM21Chf792 Solution: For the reaction C 2 H 6 C 2 H 4 + H 2 the reaction enthalpy r…

For the reaction C2H6 →\to C2H4 + H2

the reaction enthalpy Δ\Delta rH = __________ kJ mol −- 1. (Round off to the Nearest Integer).

[ Given : Bond enthalpies in kJ mol −- 1 : C-C : 347, C = C : 611; C-H : 414, H-H : 436 ]

Step-by-Step Verified Solution

JEE Main 2021 (Online) 18th March Morning Shift Chemistry - Thermodynamics Question 101 English Explanation

ΔH=EC−C+6EC−H−EC=C−4EC−H−EH−H\Delta H = {E_{C - C}} + 6{E_{C - H}} - {E_{C = C}} - 4{E_{C - H}} - {E_{H - H}}

=347+6(414)−611−4×414−436= 347 + 6(414) - 611 - 4 \times 414 - 436

=347+828−1047= 347 + 828 - 1047

=128= 128 KJ/ mol

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