ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 18, Number 3
JKCSEZ 18(3)
June 20, 1974 

The effects of ionic strength on the polynucleation reaction of tungstate ions and the protonized reaction of polytungstate ions have been investigated in the range of ionic strength from 1 M to 4 M KCl. The hexatungstate ions and the protonized forms of hexatungstate ions are formed in the tungstate solutions whose ionic strengths are 1 M to 4 M KCl. The equilibrium constants for the formation of hexatungstate ions and the protonized forms of hexatungstate ions are calculated in the range of ionic strength from 1 M to 4M KCl. The enthalpy changes for the formation of hexatungstate ions and the protonized forms of hexatungstate ions are as follows; 7H+ + 6WO42- = HW6O215- + 3H2O ΔH° = -62.4±0.6 H+ + HW6O215- = H2W6O214- ΔH1° = -4.12±0.10 H+ + H2W6O214- = H3W6O213- ΔH2° = -4.36±0.30 The free energy and entropy changes for the above reactions have been also calculated. A linear relation is formed between log K6,7 and ionic strength, and log k1 or log k2 vs.μ. log K6,7 = Dμ + I where D = 1.66±0.02 log k1 = D1μ + I1 where D1 = -8.065±0.001 log k2 = D2μ + I2 where D2 = -0.376±0.006