Question

Heat of formation of benzene, assuming no
resonance. Given that
BE (C-C) = 83 kcal
BE (C=C) = 140 kcal
BE (C-H) = 99 kcal
Heat of atomisation of C = 170.9 kcal
Heat of atomisation of H = 104.2 kcal
will be​

Answer 1

Answer:

check your question..it must be atomisation of H2 bond(=52.1 kcal)

see..you knw that..,

(delta)fH=(heat of atomisation of C)*2+(heat of atomisation of H)*4-(bond energy of C-H)*4-(bond energy of C=C)

as C has 2 moles

H has 4 moles

and C2H4 has 4 C-H bonds..

thus if u replace the values..and calculate..you are getting the value as..

(bond energy of C=C)=140.9 kcal

answer is thus (1)..

check your question..still..hope my answer helps you..^_^