| Popis: |
Tritium tracer techniques have been used to measure the solubility of water in undiluted TBP from 0 to 65°C at unit water activity and as a function of water activity at 25°C; from the latter results, the activity of the solvent has been derived by applying the Gibbs-Duhem relation. The solubility measurements were extended to include TBP- n -octane solutions that were 0.01-1.0 M in TBP, and these values were used to estimate hydration quotients. The solubility of water in undiluted TBP is 3.57 ± 0.02 M at 25°C and decreases slowly with increasing temperature. At constant temperature, the water content decreases rapidly at first and then more slowly with decreasing water activity. The variation of the activity of TBP in the diluent-free water system suggests that the extracted species is TBP·H 2 O, when the loading of TBP is less than 0.5 mole H 2 O per mole of TBP. Results of computer analyses of the solution data can be interpreted in terms of monomeric anhydrous TBP and the formation of the monohydrate TBP·H 2 O, and suggest the additional hydrate species (TBP·H 2 O) 2 , (TBP·H 2 O) 4 , and TBP·2H 2 O, with formation concentration quotients log Q TH = −0.82, log Q (TH) 2 = 1.82, log Q (TH) 4 = −0.39, log Q TH 2 = −1.66. |
