In the first article in this seriesthe motion of particles in solids was described as it relates to diffusion, sintering, and annealing 1. As a result of particle movement in solids, rate laws for reactions in solids may be dependent on diffusion processes. Rate studies on reactions of solid materials have yielded an enormous amount of information with regard to mechanisms and effects of procedural variables. To follow the extent of a reaction of a solid, some characteristic other than molar concentration must be measured. In some cases, measuring a change in mass, heat absorbed or liberated, or electrical conductivity may be possible. Reactions of solids often depend on processes that do not involve bond-breaking and bond-making in the usual chemical sense. As a result, it is necessary to describe rates of reactions in solids using kinetic models based on amount of reactant, rate of diffusion, or formation and spread of active sites. In this review, some of the general principles and descriptions of reactions and illustrations of kinetic analysis based on such factors are described.
James E. House (Sat,) studied this question.