Thermodynamic study of Al3+ ion-selective electrode based on (1E,2E) N1,N2-dihydroxy N1,N2 bis (4-hydroxyphenyl) oxalimidamide

Abstract

We have carried out thermodynamic study on the ion-selective electrode for Al(III) ions based on (1E,2E) N1,N2-dihydroxy N1,N2 bis (4-hydroxyphenyl) oxalimidamide that was previously prepared by our team. In the recent work, the electrolyte behavior was studied in the mixed solvents such as “water–ethanol” and “water–dioxane”. The electrode exhibited a good response at the temperature range of 20–50 °C. The Nernstian slope of the electrode was 19.2 ± 0.6 mV per decade. In addition the standard electrode potentials were determined at different temperatures and the results were used to calculate the temperature coefficient of the cell and the other thermodynamic functions. The temperature coefficients of the cell and the electrode are 9.99 × 10−4 V/°C and 3.93 × 10−4 V/°C respectively. The formation constant of the ionophore – Al(III) complex was calculated at 25 °C (logKf = 6.1 ± 1.1).

Keywords

• Nernstian response
• Temperature coefficient
• Mixed solvent
• Formation constant