Chronopotentiometric study of thallium¹ ion in glacial acetic acid

The thallous ion-thallium amalgam system has been studied chronopotentiometrically in glacial acetic acid (HAc) as a solvent, using 0.25M ammonium acetate as supporting electrolyte. The transition time relationships between the cathodic transition time and the first anodic transition time on current reversal were verified. Analogous studies were carried out at the thallium amalgam electrode, determining the anodic transition time and the cathodic transition time on current reversal. The predicted potential-time relationships for the above-mentioned chronopotentiometric processes were verified, and it was established that the thallous acetate-thallium amalgam couple is reversible with the formal potential of 0.347 ± 0.005 V vs. the saturated aqueous calomel electrode. The diffusion coefficients of thallous ion and thallium in mercury were found to be identical, 4.3 × 10^-6 cm², sec^-1.