The bond dissociation energy BDE is the energy required to break a bond between two atoms. In the case of ethyne gas C2H2 , we are interested in the carbon-carbon triple bond. The BDE for a carbon-carbon triple bond in ethyne is approximately 839 kJ/mol.This value is determined experimentally and can be found in reference materials such as chemistry textbooks or databases. The units for bond dissociation energy are typically given in kilojoules per mole kJ/mol , which represents the energy required to break one mole of the specified bond.