Thermodynamics of ionic-association in aqueous solutions of Ca and Mg organic salts using ion-selective electrode technique—II. benzoate, o-toloate, o-chlorobenzoate and salycylate

✍ Scribed by Mostafa M. Emara; Nazik A. Farid; Ahmed M. Wasfi

• Publisher: Elsevier Science
• Year: 1982
• Tongue: English
• Weight: 396 KB
• Volume: 27
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(82)85054-8

✦ Synopsis

The stoichiometric association constants, I(, the thermodynamic association constants, K,, and the other thermodynamic parameters such as AS', AH" and AC' for the association between each of the Ca and Mg ions with benzoate, cl-toloate, o-chlorobenzoate and salycylate have been determined at 25"C, 35°C and 45°C in aqueous media. Ion-selective electrode technique has been used in the measurements of Ca and Mg ion activities. The trend ofassociation behavior of both Ca and Mg aromatic salts could not be explained on the basis of pK of the mother organic acids but could be explained based on the trend of Hammet function 0 of these salt: themselves relative to the corresponding benzoate salt.