Journal of Solution Chemistry

, Volume 10, Issue 7, pp 479–487

Dissociation constant of aqueous trifluoroacetic acid by cryoscopy and conductivity

  • John B. Milne
  • Timothy J. Parker

DOI: 10.1007/BF00652082

Cite this article as:
Milne, J.B. & Parker, T.J. J Solution Chem (1981) 10: 479. doi:10.1007/BF00652082


The dissociation constant of trifluoroacetic acid in aqueous solution has been determined at 25°C by electrical conductivity (0.65 mol-l−1) and at 0°C by cryoscopy (1.05 mol-l−1) and electrical conductivity (0.98 mol-l−1). The good agreement between the values of the constant determined by cryoscopy and conductivity at 0°C lends confidence to the value at 25°C determined by electrical conductivity. The constant determined at 25°C is in reasonable agreement with values determined by differential refractometry (0.92 mol-l−1) and from acidity function data (0.80 mol-l−1) reported by other workers. This work renews confidence in the electrical conductivity method for determining dissociation constants of moderately strong acids.

Key words

Trifluoroacetic aciddissociation constantcryoscopyelectrical conductivityionization constantacidity

Copyright information

© Plenum Publishing Corporation 1981

Authors and Affiliations

  • John B. Milne
    • 1
  • Timothy J. Parker
    • 1
  1. 1.Department of chemistryUniversity of OttawaOttawaCanada