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CHEM 121 Studioby Learn4Less · UBC CHEM 121

CHEM 121 glossary

Bond energy

The energy needed to break one mole of a given bond in gas-phase molecules, in kJ/mol. It equals the depth of the potential-energy well; higher bond order means a larger bond energy.

Potential energy of two H atomsEnergy of two hydrogen atoms against the distance between their nuclei. Far apart the energy is zero; it falls to a minimum of −436 kJ/mol at 74 pm (the bond length; the depth is the bond energy) and rises steeply when the nuclei are pushed closer.74150225300−4360400distance between nuclei (pm)energy (kJ/mol)bond lengthbond energy

The depth of the well is the bond energy.

Example

H–H 436 kJ/mol; Cl–Cl 242 kJ/mol. For carbon: C–C 347, C=C 614, C≡C 839 kJ/mol.

See alsoBond lengthBond orderMultiple bond