Using 2,5-dinitrophenol as an optical indicator, the pKa of cacodylic acid were spectrophotometrically determined at elevated temperatures under saturation vapor pressures. The result is pKa = -26.41 + 1296/T + 4.973 In T where T is in Kelvin. In a similar way, the pKa of p-nitrophenol were obtained up to 200°C giving pKa = -24.82 + 2135/T + 4.353 In T From these results, several thermodynamic functions of cacodylic acid and p-nitrophenol were calculated.
Bibliographical noteFunding Information:
This paper was supported by the Non Directed Research Fund, Korea Research Foundation, 1994.
- Acid dissociation constant
- Cacodylic acid
- Thermodynamic function
ASJC Scopus subject areas
- Molecular Biology
- Physical and Theoretical Chemistry