The Possible Presence of Triple Ions in Electrolyte Solutions of Low Dielectric Permittivity

• Published in: Journal of solution chemistry Vol. 37; no. 7; pp. 1031 - 1035
• Main Authors: Petrucci, Sergio, Masiker, Marilyn C., Eyring, Edward M.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01-07-2008; Springer
• Subjects: Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Exact sciences and technology; General and physical chemistry; Geochemistry; Industrial Chemistry/Chemical Engineering; Inorganic Chemistry; Oceanography; Physical Chemistry; Solutions; Dielectric permittivity; Ultrasonic relaxation; Electrical conductivity; Apolar dimers; Triple ions; Dielectric permittivity .Ultrasonic relaxation; Electrolyte solution; Ions; Dimer; Permittivity; Dielectric relaxation
• ISSN: 0095-9782; 1572-8927
• DOI: 10.1007/s10953-008-9285-z

The cause of the appearance of a minimum in the molar electrical conductivity in many electrolyte solutions with increasing electrolyte concentration, in solvents of low dielectric permittivity, is reviewed. Tentative explanations include the formation of triple ions or, alternatively, changes in the electrical polarization of the solutions due to the presence of electrolyte ion pairs. Theoretical models for linear triple ions and apolar dimers are examined. Experimental evidence favors the polarization hypothesis over triple ions; the presence of a maximum in the dielectric permittivity with increasing electrolyte concentration is consistent with the presence of an equilibrium between ion pairs, AB, and their dimers, A
2
B
2
, at higher concentrations.