Argon third body

The recombination rate of chlorine atoms has been determined in flow systems with argon and with chlorine as the third body. The recommended values for k 1 and 3 are... 

The linear dependence of the second order coefficient on [Oj] shown in Fig. 3.17 confirms the dominant importance of oxygen. The close agreement of a flame in which argon was substituted for nitrogen as diluent indicates that nitrogen is not important. If carbon monoxide had any effect the line would be curved, so that it was deduced that the intercept corresponded to carbon dioxide acting as a third body, and the rate constants were ... 

Most reactions in the gas phase at low pressures can be treated as if no foreign molecules (i.e., other than reactants, intermediates, or products of the reaction) are present. Thus the presence of an inert gas such as argon is not important. An exception to this rule is any reaction in which two atoms combine to form a stable diatomic molecule. This cannot happen unless some means exists of getting rid of the energy of formation of the bond. A third body, which may be any molecule or the container... 

The number of three-body collisions is far smaller than the number of two-body collisions in a dilute gas. Consider three-body collisions in a sample of pure argon at 1.000 bar and 300 K. Assume that a three-body collision occurs when a third body collides with a pair of molecules in the act of colliding,... 

Just as water bodies such as rivers, lakes, and the ocean can be considered enormous aqueous solutions, the atmosphere is a gigantic gaseous solution. The atmosphere is composed primarily of nitrogen, 78%, and oxygen, 21%. The third most abundant gas in the atmosphere is argon, which makes up about 0.9%. The remaining 0.1% consists of... 

The dispersion energy is the universal attractive glue that leads to the formation of condensed phases. It is additive at second order in perturbation theory, and the form of the three-body term that arises at third order (the tripledipole dispersion term) is also well known from perturbation theory. This Axilrod-Teller term " was the only addition to the pair potential for argon that was required to quantitatively account for its solid and liquid state properties. This may be grounds for optimism that other nonadditive dispersion terms are negligible. Whether this can be extended to less symmetrical organic molecules and their typical crystalline and liquid environments has not yet been established however. 

The knowledge of the three-body potential allows calculations of the third virial coefficient for a substance, an experimentally accessible property that depends only on two- and three-body potentials. The classical third virial coefficient of argon has been computed in Ref. [139] for temperatures between 113.15 and 1223.15 K using the ab initio three-body potential of Ref. [32]. The results agree with the virial coefficients... 

---