【摘要】 本文测定了n-C₁₀H₂₂和n-C₁₂H₂₆在20—55℃的热压力系数。这些系数可用修正的van der Waals模型来描述式中A和B是液体的特性常数。对于n-C₁₀H₂₂:A=339.40×10^-6m³mol^-1,B=29822×10^-12m⁶mol^-2。对于n-C₁₂H₂₆:A=403.06×10^-6m³mol^-1,B=41818×10^-12m⁶mol^-2。与一般小分子液体和少于八个碳的正构烷不同,它们的B/A²不再等于0.2610,而是随着碳链的增长而逐渐减小。更多还原

【Abstract】 This paper deals with the direct measurement of thermal pressure coefficients of n-C₁₀H₂₂ and n-C₁₂H₂₆ in the temperature range 20—55℃. These coefficients can be described by modified van der Waals’ mode: in the equation, V_m stands for the molar volume of liquid, R for gas constant, A for the excluded volume of the van der Waals’ liquid and B for the rate of overlap change of the excluded volume of liquid varying with molar density. A and B are two characteristic constants of liquid. For n-C₁₀H₂₂, A=339.40×10^-6m³mol^-1,B=29 822×10^-12m⁶mol^-2 and for n-C₁₂H₂₆, A=403.06×10^-6m³mol^-1,B=41 818×10^-12m⁶mol^-2. The difference as compared with general small molecule liquids and normal alkanes with carbon atoms less than C₈, however, lies in that value of B/A² is no longer equal to 0.2610, but gradualy decreases with increasing length of carbon chain.更多还原