POLAROGRAPHIC REDUCTION OF HEXAMMINECOBALT (III) ION. THE EFFECT OF NONCOMPLEXING ELECTROLYTES
ILLINOIS UNIV AT THE MEDICAL CENTER CHICAGO COLL OF DENTISTRY
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The formation of a CoOH sub 2 film was postulated to explain the dips appearing in the diffusion current region of the first reduction wave of CoNH sub 3 sub 6 3 in perchlorate, chloride, and nitrate solutions. The film did not form after the addition of 0.02 gelatin, or with an increased concentration of the supporting electrolyte. The effects of various salts and of pH on the film formation are discussed. The addition of a small amount of Co2 during the reduction of CoNH sub 3 sub 6 3 in the presence of aquated Co2 did not cause an addition to the second wave Co2 was precipititated by the NH sub 3 which was released during the reduction of CoNH sub 3 sub 6 3, indicating that the reduction to the metallic state occurs without a hexaaquo Co2 intermediate. In the presence of bromide, thiocyanate, or iodide ions, a film of CoOH sub 2 was formed by the direct interaction of Hg. The diffusion current of CoNH sub 3 sub 6 3 was measured in supporting electrolytes of different charge type and known viscosity. The diffusion current was inversely proportional to the square root of the viscosity. The masking effect of viscosity on the diffusion rate was independent of the nature of the electrolyte, provided the charge of the ion was kept constant. The results indicated that, in addition to the effect of viscosity, there was a suppressing effect which increased with the increasing charge of anion. This effect is consistent with the concept of electrostatic clustering Laitinen and other, J. Am. Chem. Soc. 702999, 1948.
- Atomic and Molecular Physics and Spectroscopy