Estimate enthalpy change for combustion of 1 mole of acetylene C2H2 to form CO2 and H2O vapor.?

Question

Estimate the enthalpy change for the combustion of one mole of acetylene, C2H2, to form carbon dioxide and water vapor. Given the following bond dissociation energies:

D(C-H) = 456kj/mol

D(C=-C) = 962 kJ/mol (triple bond, sorry...)

D(O=O) = 499 kJ/mol

D(C=O) =802 kJ/mol

D(O-H) = 462 kJ/mol

Answer choices are all in kj/mol units:

-1759

+653

+1010

-1010

-155

I calculated all of the energies, plus and minus, including the O2 change and came up with -155. Then I remembered that ground state oxygen isn't added into the equation, so now I don't have an answer. Help please?

Answer 1

C2H2 + (5/2)O2 → 2CO2 + H2O

962 + (2)(456) + (5/2)499 = (2)(2)(802) + (2)(462) + E

E = - 1,010.5 kJ/mol ≈ - 1,010 kJ/mol