Kinetics and thermodynamics of Ni/Ni(II) reactions in concentrated solutions of nickel and calcium chlorides

✍ Scribed by T. Hurlen

• Publisher: Elsevier Science
• Year: 1975
• Tongue: English
• Weight: 665 KB
• Volume: 20
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(75)90040-7

✦ Synopsis

The title subject has been studied through stationary and transient polarization measurements (combined with stirring and ring-disc experiments) on the Ni/Ni(II) electrode and equilibrium measurcments on the Ag/AgCl electrode at 25°C. The Ni/Ni(II) electrode is found to react m two consecutive steps with Ni(I) as intermediate. The ion-transfer step Ni/Ni(I) is chloride independent and seems mostly to occur directly at kink sites. The electron-transfer step Ni(I)/Ni(II) involves parallel transfer by the couplesNi(H,O),t/Ni(H,O)~+andNiCl(H,O),/NiCl(H,O)~ andisindependentofkinksites.Nocleareffect or sign is seen of possibly adsorbed chloride ions. Data are obtained for the mean ionic activity coefficient of NiCl, in the mixed solutions aDalied. An attemut is made to determine single-ion activities by comhin-I a ing kin&c and thermodynamic data.