JEE MAIN - Chemistry (2021 - 18th March Morning Shift - No. 18)

For the reaction C2H6 $$ \to $$ C2H4 + H2

the reaction enthalpy $$\Delta$$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 ]
Answer
128

Explanation

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

$$\Delta H = {E_{C - C}} + 6{E_{C - H}} - {E_{C = C}} - 4{E_{C - H}} - {E_{H - H}}$$

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

$$ = 347 + 828 - 1047$$

$$ = 128$$ KJ/ mol

Comments (0)

Advertisement