Journal of Solution Chemistry

, Volume 35, Issue 4, pp 583–604

Deliquescence Relative Humidity Measurements Using an Electrical Conductivity Method

  • Lietai Yang
  • Roberto T. Pabalan
  • Miriam R. Juckett
Article

DOI: 10.1007/s10953-005-9015-8

Cite this article as:
Yang, L., Pabalan, R.T. & Juckett, M.R. J Solution Chem (2006) 35: 583. doi:10.1007/s10953-005-9015-8

Abstract

Several methods used in the published literature for determining the deliquescence relative humidity (DRH) of salts and the mutual deliquescence relative humidity (MDRH) of salt mixtures were reviewed. Experiments were conducted to evaluate an electrical conductivity method for determining the DRH of salts and the MDRH of salt mixtures. The electrical impedance of a conductivity cell containing Na2SO4, CaCl2 and NaCl+NaNO3+KNO3 was measured as a function of relative humidity at temperatures up to 70 C. To provide a basis for interpreting the results of the impedance measurements, computer modeling of the specific electrical conductivity of single salts and salt mixtures at 25 C also was performed. The results of the study demonstrated that the electrical conductivity method provides a convenient and accurate method for determining the DRH of single salts and the MDRH of salt mixtures. The derived DRH and MDRH values were in good agreement with those determined using a hygrometer method. The conductivity method, however, is a more reliable technique than the hygrometer method for determining the MDRH of salt mixtures because the conductivity method is insensitive to slight deviations of mixture composition from the eutonic value.

Key Words

Deliquescencerelative humiditysalt mixturesconductivityimpedance

Copyright information

© Springer Science+Business Media, Inc. 2006

Authors and Affiliations

  • Lietai Yang
    • 1
  • Roberto T. Pabalan
    • 1
  • Miriam R. Juckett
    • 1
  1. 1.Center for Nuclear Waste Regulatory AnalysesSan AntonioUSA