Condensation of Potassium Hydroxide Solution in a Silver Vessel under Cathodic Protection

Abstract

Ultra-pure solid potassium hydroxide was prepared by the evaporation of KOH solution in cathodically protected silver vessel. Relation among amount of silver dissolved, KOH concentration and cell voltage (potential between Ag vessel cathode and Pt anode) was investigated passing a protecting current in a siver vessel.
The purity of KOH obtained was 96.9 % and the amount of silver dissolved from cathode was 0.00022% at the cathodic current density of 6 mA/cm². The dissolution of silver was observed to increase with the decrease of cell voltage.