Practical potentiometric determinations of proton activity in hydro organic solvents at subzero temperatures

✍ Scribed by Christian Larroque; Patrick Maurel; Claude Balny; Pierre Douzou

• Publisher: Elsevier Science
• Year: 1976
• Tongue: English
• Weight: 604 KB
• Volume: 73
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(76)90136-6

✦ Synopsis

A practical method of potentiometric determinations of pa" using a glass electrode in hydro organic solvents at normal and subzero temperatures (20 to -40°C) is presented. This method is based on appropriate modifications of both glass and calomel electrodes and salt junction. In particular, the inner reference solution of the glass electrode, and the salt junction solution are prepared in hydro organic solvents whose freezing point is very low. The pun response of such a glass electrode determined either using operational standard solutions or previously reported pa,, data obtained by indicator spectrophotometry in these conditions, is shown to be in good agreement with the theoretical figures, both at normal and low temperatures. Some preliminary experimental data are reported and further applications of potentiometric determinations of par, in these conditions are mentioned.

' pa" = -log aH, aH being the protonic activity in the medium.