Bond-dissociation energy
The binding energy, average binding energy (also: dissociation energy, bond cleavage energy, binding enthalpy, Bindungsdissoziationsenthalpie, Valenzenergie ) is in chemistry, the amount of energy called, which must be expended in order to completely cleave the covalent bond between two atoms of a molecule. Here there are two radicals ( homolytic cleavage ) form. The power is usually given in Joules per mole of compound and describes the strength of the bond. If all bonds dissociated, it is called atomization or Atomisierungswärme, which is the total binding energy of a connection. The molar binding energy of ionic crystals is described by lattice energy.
The bonding energy different from the standard formation, originating from reactions of the elements in its stable form. The binding energy is equal to the energy of a heterolytic cleavage ( ionization), which is significantly greater than that of a homolytic bond cleavage. In physics, under most of the binding energy, the binding energy of an electron in the atom or the binding energy of the atomic nucleus understood to refer to the binding energy.
The real strength ( true binding energy ) can be experimentally determined, since the fragments, inter alia, the arrangement of their binding partners ( for molecules that consist of more than two atoms) and change their electronic structure. Some separation energies can be determined experimentally in single steps (see example methane ), other separation energies can be estimated by calculation from existing data. To estimate known average binding energies are used.
The size of the binding energy depends, among other things, the bond length (the longer the lower), the polarity of the compound ( polar atomic bonds are more difficult to split the non-polar ) and the type of bond ( single bond can be lighter than a double bond, which in turn easier than a triple bond split ) from.