HYDROLYSIS OF TRIMETHYLTIN(IV) CATION IN NANO3 AND NACL AQUEOUS-MEDIAAT DIFFERENT TEMPERATURES AND IONIC STRENGTHS

The hydro lys is constants of trimethyltin(Iv)cation were determined p otentiometrically ([H+]-glass electrode) in NaNO3 and NaCl aqueous sol ution, at different values of ionic strength (0 less than or equal to I less than or equal to 1.5 mol.dm(-3)) and temperature (5 less than o r equal to T less than or equal to 45, degrees C). For the hydrolysis reaction (CH3)(3)Sn+ = (CH3)(3)SnOH degrees + H+, log K-11 = 6.141+/-0 .002 and Delta H degrees = 25.8+/-0.3 kJ.mol(-1) (25 degrees C, I = 0) were found. At high pH values the species (CH3)3Sn(OH)(2)(-) is also present. The dependence on ionic strength was considered by using a si mple linear relationship. The differences between the values of log K- 11 in NaCl and in NaNO3 were interpreted in terms of chloride complex formation.