Vapor Pressure and Enthalpy of Vaporization of 2-Amino-3-methylpyridine

• Published in: Journal of chemical and engineering data 2007-11, Vol.52 (6), p.2431-2435
• Main Authors: Yuan, Xiong-Jun, Xue, Wei-Lan, Zeng, Zuo-Xiang, Pu, Tong
• Format: Article
• Language: English
• Subjects: Chemical thermodynamics; Chemistry; Elements, mineral and organic compounds; Exact sciences and technology; General and physical chemistry; Thermodynamic properties
• ISSN: 0021-9568; 1520-5134
• DOI: 10.1021/je700371w

The vapor pressure of 2-amino-3-methylpyridine was measured in the temperature range of (328.70 to 499.88) K using the boiling point method. The Antoine equation was used to describe the vapor pressure data, and the parameters in the equation were determined by means of the least-square regression method. The deviation of experimental data from the corresponding calculated values was within 0.30 %. On the basis of the equation, the enthalpy of vaporization of 2-amino-3-methylpyridine at normal boiling point (T b) was obtained from the slope of the plot of ln p vs 1/T. The standard enthalpy of vaporization Δvap H(298.15 K) was estimated by Othmer's method. Using 3-methylpyridine as the standard substance, the value of Δvap H(298.15 K) was found to be 62.58 kJ·mol-1. A parallel value of Δvap H(298.15 K) was also obtained using benzene as the standard substance. Additionally the Watson relation was employed to verify the value of Δvap H(298.15 K), from which it was shown that the value of the standard enthalpy of vaporization was acceptable.