Abstract: In this experiment, a series of the pyridine and 2,6-lutidine solutions with different pH values were preparcd, then the ¹H spectrum of each sample was measured with a 80MHz NMR spectrometer.Therefore, the pK_a values depending on both the pH value and ionic concentration of the solution were calculated and thermodynamic parameters △G, △H and △S were obtained according to the data gotten through changing the experimental temperature of the system.It is shown that the NMR method is reliable and more convenient than conventional pH method when applied to the determination of pK_a and thermodynamic parameters of pyridine and 2,6-lutidine solutions.

Key words: ¹H NMR, Pyridine compound, pK_a, Thermodynamic parameter