Using average bond energy values estimate ΔH for the following gas phase reaction.?

Question

C2H4 + H2O2 → CH2(OH)CH2(OH)

Answer 1

you are going to need the following average bond values to do this question:

C-C, C-H, O-O, C-O and O-H

first calculate the energy needed to break all bonds in the reactants. i label this deltaH bond breaking, and it is calculated to be 1(c-c)+4(c-h)+1(o-o)+2(o-h). the sum is positive indicating an endothermic process.

then calculate the energy released to form all the bonds in the products. lets label this deltaH bond forming. this is -[4(c-h)+1(c-c)+2(o-h)+2(c-o)]. we use a negative sign for the sum because bond forming is an exothermic process.

the deltaH reaction is thus the sum of both the calculated enthalphies, which i am inclined to believe is slightly negative.