| Popis: |
According to the slow discharge theory, small additions of multicharged cations accelerate the charge-transfer step during the electroreduction of anions of K 3 (Fe(CN) 6 ), K 2 S 2 O 8 and Na 2 S 4 O 6 salts. However, this effect decreases as the negative charge on the mercury electrode increases, which contradicts the predictions of the slow discharge theory in combination with the Gouy-Chapman-Grahame model of the electric double layer. It is shown that the observed results can be explained within the framework of the diffuse-layer model, according to which singly charged cations of a salt in which the anion is being reduced approach the metal surface more closely than the hydrated multicharged cations because of their smaller Stokes radius. |
