Determination of stability constants of stannous fluoride complexes by potentiostatic titration

The stability constants for stannous fluoride complexes were determined by potentiostatic titration. The method involves incremental additions of fluoride wherein each addition is followed by titration with stannous such that there is no change in the electromotive force developed between the fluoride ion and the reference electrodes. The values obtained were beta1 equals 4 times 10-3, b2 equals 1.1 times 10-7, and b3 equals 1 times 10-9. The results of this work suggest that the potentiostatic method wound be useful for determining stability constants in complexation systems involving an ion for which a specific on electrode is available.