The Commonly Encountered Vanadates

Under very strongly basic conditions, the vanadate trianion, V043-, will be the only vanadate in solution. The V04H2 ion has a pKa of about 12. Consequently, below 

FIGURE 2.4 51V NMR spectrum obtained under slightly alkaline conditions showing a typical distribution of vanadate and its oligomers in aqueous solution. Conditions of experiment total vanadate, 6 mmol/L pH, 8.0 NaCl, 1.0 mol/L. 

FIGURE 2.5 Species distribution diagrams for vanadate at 1.0 and 0.1 molar overall concentrations calculated for aqueous 0.6 mol/L NaCl solutions. Formation constants are taken 

Formation Constants for Selected Vanadate Oligomers Determined in the Presence of Various Electrolytes and Electrolyte Concentrations 

Electrolyte 2H2V04- 2 V2072-K,2 4H2V04- 14 V40124-K,4 Kl5 5H2V04- V50155-K,s PKa (H2V04 ) Ref. 

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