Diffusion Coefficient Of Iodine Research Articles

The impedance of the Pt/Ag 4RbI 5 and C/Ag 4RbI 5 interphases at anodic potentials

Impedance measurements have been made on the Pt/Ag 4 RbI 5 and C/Ag 4 RbI 5 interphases. Rate constants for the electrochemical oxidation of I − to I 2 on Pt have been determined. Steady-state measurements have enabled calculation of the solubility and diffusion coefficient of iodine in Ag 4 RbI 5 . The variation of these characteristics with pressure and particle size of electrolyte has also been investigated. The results are in agreement with those obtained from transient measurements.

Über die elektrochemische oxydation von Jodid und Jod zum hypojodit an graphitelektroden

On electrochemically oxidizing iodide at a disk electrode consisting of a graphite—azobenzene mixture the wave due to hypoiodite formation is observed. Its height is (a) independent of pH (b) proportional to the concentration of iodide or iodine respectively, (c) dependent on rate of rotation in a manner indicating that a preceding heterogeneous first-order reaction is rate determining. The limiting current is not, however, dependent on electrode composition.The thickness of the reaction layer of the homogeneous, quasi-heterogeneous reaction I2 + H2O ⇌ I− + HOI + H+ is very small in comparison with the diffusion layer. The potential/current density relationship based on this assumption was deduced and found to be in full agreement with experiment, including the potential at which the hypoiodite wave occurs.In more alkaline solution the hypoiodite step increases to its diffusion-dependent value. This is due to the fast parallel reaction I2 + OH− → HOI + I−. The diffusion coefficient of iodine calculated from the hypoiodite wave is too small, owing to the formation of J3OH. The dependence of concentration on distance from the electrode within the Nernst Layer was calculated by computer for iodine reduction. The formation of triiodide does not noticeably influence the calculated diffusion coefficient of iodine.

LXXX.Experiments on the rate of evaporation of small spheres as a method of determining diffusion coefficients.—The diffusion coefficient of iodine

(1927). LXXX. Experiments on the rate of evaporation of small spheres as a method of determining diffusion coefficients.— The diffusion coefficient of iodine. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science: Vol. 4, No. 24, pp. 873-888.