Using the following bond energies Bond Bond Energy (kJ/mol) C?C your knowledge C-H 413 O=O 495 C=O 799 O-H 467 estimate the heat of combustion for one mole of acetylene: C2H2(g) + (5/2)O2(g) ? 2CO2(g) + H2O(g) I. +365 kJ II. -447 kJ III. +447 kJ IV. 1228 kJ V. -1228 kJ