For the study of the temperature dependence of reversibility of an electrode process, (1) the temperature coefficient of AC polarographic peak height Y
AC was measured, and (2) a new method of plotting log ( Y
AC⋅T) against the reciprocal of the absolute tem-perature was introduced. It was confirmed that the temperature coefficient of Y
AC decreases with the increasing reversibility and temperature. And the temperature range, in which the electrode re-action is controlled either by diffusion or by electron-transfer process, was found from the plots shown in Fig. 2. It was found that the product Y
AC ⋅T is proportional to the diffusion current in higher temperature range, and to the exchange current density in the lower temperature range. And the activation energy of diffusion and that of the electrode reaction at the normal potential of zinc ion were obtained from the plot of log (Y
AC⋅T ) vs. 1/T.
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