Heat Capacities of Liquids and Vapors
Heat Capacities of Liquids and Vapors
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液体和蒸气的热容
DOI：
10.1063/1.1746364
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发表时间：
1947
影响因子：
4.4
通讯作者：
S. Benson
中科院分区：
文献类型：
--
作者：
S. Benson
通过使用先前导出的液体汽化能公式：ΔE=k(Dln-Dgn)(其中k是常数；n=5/3，并且Dl和Dg分别是液体和蒸汽的摩尔密度)，推导出与液体和蒸汽在恒压下的摩尔热容之差有关的表达式(∂ΔE/∂T)(ΔCp)。在低压下，这个关系可以用方程ΔCp=(∂ΔE/∂T)S+R(R是气体常数，1.986卡/摩尔-°A)来近似。在此条件下(∂ΔE/∂T)S=(5/3)ΔE(∂ Ind1/∂T)S，得到的ΔCP方程为ΔCp=(5/3)ΔE(∂ Ind1/∂T)S+1.99。根据液体的已知性质，可以使用最后一个方程计算ΔCp。这些计算值与实验值符合得很好。
By the use of an equation previously derived for the energy of vaporization of a liquid: ΔE=k(Dln—Dgn) (in which k is a constant; n=5/3, and Dl and Dg are the molar densities of liquid and vapor, respectively), an expression is derived relating (∂ΔE/∂T)sat to the difference in molar heat capacities at constant pressure of the liquid and vapor (ΔCp). At low pressures this relation can be approximated by the equation ΔCp=(∂ΔE/∂T)s+ R (R is the gas constant, 1.986 cal./mole‐°A). Under these conditions (∂ΔE/∂T)s=(5/3)ΔE(∂ lnDl/∂T)s, and the resulting equation for ΔCp is ΔCp=(5/3)ΔE(∂ lnDl/∂T)s+1.99. From known properties of liquids ΔCp can be calculated using this last equation. These calculated values are found to be in good agreement with observed experimental values.