Abstract: In this paper numerical modeling was used to investigate kinetics of diffusion and diffusion with a first-order reaction in a gelatin layer, with which the space distributions of a diffu-sant in a gelatin layer at different times were obtained. The advantages of these computerized models over the conventional analytical method were: 1) easier to find numerical solutions; 2) of more potential to study rather complicated processes of diffusion with chemical reactions in gelatin layer. In order to verify the reliability of these models, the cooresponding analytical solutions were used by comparison.

Key words: chemical kinetics, computer simulation, computional chemistry, photographic chemistry