Question

C2H4 = 12.5 kcal
Heat of atomisation of C = 171 kcal
Bond energy of H2 = 104.3 kcal
Bond energy C-H = 99.3 kcal
What is C = C bond energy?
(1) 140.9 kcal
(2) 49 kcal
(3) 40 kcal
(4) 76 kcal​

Answer 1

Answer:

ΔH

f

of C

2

H

4

=12.5kcal Heat of atomisation of C=171kcal. Bond energy of H

2

=104.3kcal. Bond energy C−H=99.3kcal.