2-碘-3-硝基甲苯的低温热容和热力学性质

Low - temperature Heat Capacity and Thermodynamic Properties of 2-Iodo-3-nitrotoluene

通过精密自动绝热热量计测定了2-碘-3-硝基甲苯(C_7H_6INO_2)在79～373K温区的摩尔热容.实验结果表明,这个化合物在331～340K温度区间有一个固-液熔化相变,其熔化温度、摩尔熔化焓、摩尔熔化熵以及该样品的化学纯度分别为:(339.311±0.035)K,(20677.54±40.09)J·mol^(-1),(61.04±0.13)J·mol^(-1)·K^(-1)和99.73％.用热容多项式方程进行数值积分获得了该物质在298.15～370K温区每隔5K的热力学函数值.用DSC分析对它的固-液相变过程作了进一步的研究.

The heat capacity of 2 - iodo - 3 - nitrotoluene was precisely determined with a small sample precision automated adiabatic calorimeter over the temperature range from 79 to 373K. A phase transition from solid to liquid was observed at the peak temperature of (339.311±0.035)K. The molar enthalpy and entropy of the phase transition as well as chemical purity of the substance were determined to be (20677.54±40.09) J·mol-1, (61.04±0. 13)J·mol-1·K-1 and 99.73%, respectively, on the basis of the heat- capacity measurements. The further research of solid - liquid phase transition for this compound were carried out by means of DSC technique.