Physico-Chemical Investigation on Thiomalate Complex of Thallium (I)

Potentiometric and conductometric studies of the complex formed by Thallium (I) with Thiomalic acid in aqueous medium of 0.1M KNO₃ reveal the formation of only one colourless 1 : 1 complex, predominating in the \(p\)H range 9.0-10.5. The stability constants of the complex formed were computed by Calvin and Melchior's extension of Bjerrum's method at three different temperatures. The log K values were found to be 3.58, 3.71 and 3.78 at 30°, 35°, and 40° respectively. The values of ∆G, ∆H and ∆S calculated at 35° are-5.22 kcal/mole-5.75 kcal/mole and -1.7 k. cal/respectively.