The diffusion coefficient of copper sulphate in aqueous solution

✍ Scribed by T.I. Quickenden; X. Jiang

• Publisher: Elsevier Science
• Year: 1984
• Tongue: English
• Weight: 699 KB
• Volume: 29
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(84)80002-x

✦ Synopsis

The diffusion coeficient, D, of CuSO, in aqueous solution was determined at 298.1 K by chronopotentiometry and also with a rotating disc electrode using the mixed control Levich equation. For 0 < [CuSO,] < 0.05 moldm-3,D = 17.35 &O.iS-(5.3* l.4)[CuS0,]'~Z} x 10-'DmZs-', at a constant ionic strength of 1.58 moldm-"maintained with either H2S01 or Na,SO, (pH = 2). It was shown that substantial variations in the concentration of the supporting electrolyte had negligible effect on the above values of D. It was found that literature values of D vary over a three-fold range, even when corrected to the same temperature and CuSO, concentration. Much of this variation probably arises from rotating disc determinations carried out at disc potentials where activation control is significant. This problem is overcome if the mixed control Levich equation is used to treat the data instead of the commonly used simple (diffusion only) Levich equation.