A Quantumhyphen;Mechanical Calculation of the Rates of Some Chemical Reactions

摘要

The rates of many simple chemical reactions of the type AB+Crarr;A+BC are empirically known to be of the formkOF=PZexp(mdash;EA/kT). On the theory that the reactions take place through the interchange of translational and vibrational energy, a qualitative quantumhyphen;mechanical calculation of the ratekOFis made for the simple model of collinear collisions. The empirical values of the activation energyEAare employed to fix the interaction potential for a given reaction. On identifying the quantumhyphen;mechanical expression for the ratekOFwith the empirical expression above and on using the gas kinetic expression for the mean number of collisionsZ,it is possible to calculate the probability factorP.Numerical calculations have been carried out for the two reactions H2+Xrarr;HX+H, where X is Cl or Br. In both cases,Pis found to be about 8times;10minus;3.