化学学报 ›› 2001, Vol. 59 ›› Issue (4): 496-501. 上一篇    下一篇

研究论文

1-甲基-3,5-二苯基-吡唑的低温热容和热力学性质

邸友莹;孙晓红;刘源发;谭志诚;孟霜鹤;高胜利;屈松生   

  1. 武汉大学化学与环境科学学院;中国科学院大连化学物理研究所热化学实验室
  • 发布日期:2001-04-15

Low-temperature heat capacities and thermodynamic properties of 1 methyl-3,5-diphenyl-pyrazole

Di Youying;Sun Xiaohong;Liu Yuanfa;Tan Zhicheng;Meng Shuanghe;Gao Shengli;Qu Songsheng   

  1. Northwest Univ, Dept Chem.Xian(710069)
  • Published:2001-04-15

通过精密自动绝热热量计测量了自己合成并提纯1-甲基-3,5-二苯基-吡唑在78~370K温区的摩尔热容。实验结果表明,这个化合物有一个固-液熔化相变,其熔化温度、摩尔熔化焓以及摩尔熔化熵分别为:(332.903±0.152)K,(17463.48±21.81)J·mol^-1和(52.55±0.06)J·mol^-1·K^-1。通过分步熔化法得到样品的纯度和绝对纯样品熔点分别为:0.9954(摩尔分数)和333.115K。在热容测量的基础上计算出了该物质每隔5K的热力学函数值。用DSC技术对该物质的固液熔化过程作了进一步研究,结果与热容实验相一致。

关键词: 吡唑P, 比热, 热力学性质, 示差扫描量热法

The heat capacities of 1-methyl-3,5-diphenyl- pyrazole have been precisely determined with a small sample precision automated adiabatic calorimeter over the temperature range from 78 to 370 K. A phase transition form solid to liquid is observed at the peak temperature of (332.903±0.152)K. The molar enthalpy and entropy of the phase transition as well as chemical purity of the substance are determined to be (17463.48±21.81)J·mol^-1,(52.55±0.06)J·K· mol^ 1 and 99.54%, respectively, on the basis of the heatcapacity measurements. The further research of solid-liquid phase transition for this compound has been carried out by means of DSC technique.

Key words: PYRAZOLE P, SPECIFIC HEAT, THERMODYNAMIC PROPERTIES, DIFFERENTIAL SCANNING CALORIMETRY

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