Dissociation energy average

Tables 2.3 and 2.4 list a selection of typical dissociation energies. The values given in Table 2.4 are average dissociation energies for a number of different molecules. For instance, the strength quoted for a C—O single bond is the average strength of such bonds in a selection of organic molecules, such as methanol (CH3—OH), ethanol (CH,CH2—OH), and dimethyl ether (CH,—O—Cl l5). The values should therefore be regarded as typical rather than as accurate values for a particular molecule.

Wc shall not distinguish between the average dissociation energy and the average dissociation enthalpy, a concept to be introduced in Section 6.20. The two quantities differ by only a few kilojoules per mole. 

The average dissociation energy of bonds forming the structure of a macromolecule appears thus to be a first criterion for estimating the thermal stability of a given polymer. The fraction of bonds that reaches the energy equal to dissociation energy D is determined by the Boltzman s factor... 

These are average dissociation energies based on one-half of (he energy required for the reaciion, CpzM(8)- Mte) + 2Cp(g). 

For polyatomic molecules, bond strength is defined as the average dissociation energy for one type of bond found in different molecules. 

Values of average dissociation energies in text Table 2.4 are actually those for the property of bond enthalpy (see Chapter 6), measured at 298.15 K. The bond dissociation energies of diatomic molecules given in Table 2.3 apply at 0 K (absolute zero). 

Type of bond Bond length in A Average dissociation energy (kcal/mol) Type of bond Bond length in A Average dissociation energy (kcal/mol)... 

Average dissociation energy of a single association Molar ratio of CTAB to the AAc units in the polymer CTAB/AAc molar ratio in the gelation solution Critical shear rate for shear thickening Relaxation rate of the fast mode Strain amplimde... 

The benefits include a second approach to the thermodynamics, the first resting on the state functions responsible for Equations (6.1) through (6.4). This is because still more tables of first-year chemistry texts provide the average dissociation energies ( )) of atom-bond-atom (ABA) components, for example ... 

Table 7.4. Activation Parameters for the Thermal Decomposition of [Cp2MJ, Together with Average Dissociation Energies, Average Free Energies, and Average Entropies of...

Note Values of average dissociation energies in text Table 3.4 are actually those for the... 

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