Oxygen-containing molecules, bond

Calculation of Reference Bond Energies [Eq. (10.39)]. The parameters indicated in Table 10.4 are ready for use in the bond energy formula, Eq. (10.39). The following examples, in part based on detailed results given in Chapters 15 and 16 for nitrogen- and oxygen-containing molecules, illustrate the procedure and report the input data. 

Another unique characteristic of oxygen-containing molecules is their exceptionally strong X-0 bonds. For example, the gas-phase enthalpies for homolytic bond dissociation (AHdbe) are H-0% 103 kcalmol" HO-H, 119kcalmol CO, 257kcalmol BaO, 134kcalmofr FeO, 93 kcalmol". ... 

The need for quantitative bond energy data for oxygen-containing molecules in the condensed phase has prompted the development of an evaluation procedure that is based on electron-transfer thermodynamics. The approach is illustrated for H-O bonds and for Fe-0 bonds, but is applicable to any X-O bond for which appropriate electron-transfer potentials are available. Table 6(a) summarizes the one-electron standard reduction potentials for H3O+, HO-, HOH, O2, HOO-, 02 % -O-, and in aqueous solutions (see Table 1). 

Table 5 Gas-phase dissociative bond energies for oxygen-containing molecules...

The HOH molecule (oxygenated hydrogen) is the most important oxygen-containing molecule and is fundamental to the realm of oxygen chemistry. It possesses exceptional ruggedness and thermal stability by virtue of strong chemical bonds... 

Table 3-6 Gas-Phase Dissociative Bond Energies (AHdbe) for Oxygen-Containing Molecules ...

When writing a Lewis structure we restrict a molecule s electrons to certain well defined locations either linking two atoms by a covalent bond or as unshared electrons on a sm gle atom Sometimes more than one Lewis structure can be written for a molecule espe cially those that contain multiple bonds An example often cited m introductory chem istry courses is ozone (O3) Ozone occurs naturally m large quantities m the upper atmosphere where it screens the surface of the earth from much of the sun s ultraviolet rays Were it not for this ozone layer most forms of surface life on earth would be dam aged or even destroyed by the rays of the sun The following Lewis structure for ozone satisfies fhe ocfef rule all fhree oxygens have eighf elecfrons m fheir valence shell... 

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