Regularities of liquid potassium at different temperatures

Several new regularities in liquid potassium have been found from the existing experimental data and calculated thermodynamic properties along the isothermal lines with the equation of state (EoS) of a power law form. The quantity (Z − 1)V2 is linearly proportional to V2 with a common intersection point for all isotherms at high temperature and PintV versus V−2 is nearly linear, where Z, V and Pint are compressibility factor, molar volume and internal pressure. Both the isothermal bulk modulus and internal pressure are nearly a linear function of pressure at constant temperature. There is a linear relationship existing between the calculated reduced isothermal bulk modulus and V−2. Based on the linear isotherm regularity EoS, analytical expression of thermodynamic properties of liquid potassium can be obtained. Furthermore, we found crossing points existing in the isobaric thermal expansion coefficient and Anderson-Grüneisen parameter.