Thermodynamic Stability of Zirconium(IV) Complexes with Hydroxy Ions

✍ Scribed by Anne Veyland; Laurent Dupont; Jean-Claude Pierrard; Jean Rimbault; Michel Aplincourt

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 252 KB
• Volume: 1998
• Category: Article
• ISSN: 1434-1948
• DOI: 10.1002/(sici)1099-0682(199811)1998:11<1765::aid-ejic1765>3.0.co;2-#

✦ Synopsis

Zirconium(IV) / Hydroxy ion / Complexes / Protometry / Equilibrium constant / Solubility product A protometric study on the speciation of zirconium(IV) was computed and refined, by the program PROTAF, for each ionic strength. The solubility product Ks of Zr(OH) 4 was performed in an aqueous solution at 25 °C in KNO 3 and four ionic strengths (0.2, 0.5, 1, and 2 mol•dm -3 ). This study calculated by taking these β mlh constants into account. The thermodynamic values were determined by extrapolation at indicates the formation of the soluble species Zr(OH) 3 + , Zr 2 (OH) 7 + , and Zr(OH) 4 in the pH range 1.5-3.5. The use of zero ionic strength (Specific ion Interaction Theory method): log β°1 0-3 = -0.52 (0.01); logβ°2 0-7 = Ϫ2.22(0.07); logβ°1 0Ϫ4 = an appropriate titration technique allows the precipitation of the zirconium hydroxide to be limited. The overall stability Ϫ4.52 (0.07); logKs°= Ϫ55.26(0.08). constants β mlh of these three hydroxo complexes were