Kinetics and mechanism of reaction between mercuric bromoiodide and silver iodide in solid state

Kinetics and the mechanism of the reaction between mercuric bromoidide and silver iodide in solid state were studied by X-ray, chemical analysis, thermal, and electrical conductivity measurements. HgBrI and AgI react in the molar ratio 1:3 to give AgBr and Ag₂HgI₄. The data for the lateral diffusion fit best in the equation X_iⁿ = kt. It has been established that the reaction proceeds via a vapor phase diffusion-controlled mechanism through counterdiffusion of Ag⁺ and Hg²⁺. There also seems to be some evidence for the formation of solid solutions between reactant and product phases.