Revert and direct type liesegang phenomenon of silver iodide

Abstract The experimental conditions for Liesegang phenomenon of silver iodide in agar gel columns, and particularly the transition from revert to direct type of periodic precipitations, have been investigated. The theoretically derived Mathur's spacing law, which suits both revert and direct type of Liesegang's rings, has been experimentally verified. An attempt has been made to explain the mechanism of revert and direct type and of the transition of revert to direct type of periodic precipitation on the basis of adsorption on the precipitated silver iodide and of flocculation. The dependence of the transition point on the concentrations of the outer and inner electrolytes has been studied. The time law of Morse and Pierce has been verified. The dependence of the velocity constant ( K = x n t n 1 2 ) on the concentrations of the outer and inner electrolytes has been studied.