Studies on Liesegang rings of cobalt hydroxide in 1% agar gel medium

- The pH of inner electrolyte plays important role in periodic precipitation of cobalt hydroxide.
- Concentration of inner and outer electrolyte affects morphology of rings.
- The Cobalt hydroxide system obeys all basic laws of Liesegang rings formation viz., time law, width law and spacing law.
- The concentration of cobalt ions in between two successive rings is negligible.
- The experimental value of diffusion coefficient is higher than that of the theoretical diffusion coefficients.

The present work deals with the studies on periodic precipitation of cobalt hydroxide system in 1% agar gel medium. For this purpose ammonium hydroxide was used as an outer electrolyte and cobalt chloride as an inner electrolyte. The effect of inner electrolyte concentration on the morphological characteristics of periodic precipitation was studied. These include size of the rings, spacing between the rings and number of rings produced per day. The concentration of reacting ions within the ring and in between successive rings was estimated by atomic absorption spectroscopy technique. The obtained results were verified on the basis of spacing law, time law and width law. The study also includes determination of diffusion coefficient of inner electrolyte at studied concentrations.