Abstract

Dissociation constants at 30 °C of picric acid have been determined by a spectrophotometric method in ethanol–sulfolane and t-butyl alcohol – sulfolane mixtures over the entire solvent composition range. Picric acid behaves as a weak acid in all mixtures. In pure sulfolane, picric acid undergoes simple dissociation for c < 0.08 M (pKHPI = 7.6). At concentrations higher than 0.08 M more complex equilibria have been observed and interpreted assuming Pi(HPi)2− as the principal picrate species in solution. Complex behavior of dependence of association constant on solvent composition was observed; in both solvent mixtures as sociation of picric acid decreases with decrease of dielectric constant. This behavior was discussed in terms of preferential solvation of picric acid by alcohols, the more basic components of the mixtures. A reaction mechanism of four alcohol molecules with one acid molecule accounts for the behavior observed.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.