EOS of Earth's Fluid
EOS of Earth's Fluid The HDAC is used to determine the pressure-volume-temperature-composition (PVTX) relations in H2O and NaCl-H2O systems to 12 kbar and 850 C. An isochore of pure H2O was determined by measuring the a-b quartz transition temperature and the liquid-vapor homogenization temperature in an H2O sample of constant volume. Eight isochores of pure H2O determined by this method were subjected to a statistical procedure of analysis of variance (ANOVA) and post hoc test. The analyzed results when used to assess various published equations of state of H2O show that the formulation by Haar et al. (1984) has the smallest significant deviations in transition pressures and molar volumes from those determined in this study.
Thirty-six isochores of aqueous sodium chloride solutions with compositions ranging from 5 to 26 weight % NaCl were determined. The composition of a solution sample can be determined by measuring the ice melting point or the halite dissolution temperature. The obtained PVTX relations at high concentrations are in excellent agreement with the data of Zhang and Frantz (1986). The formulation for this new data set has a precision of ± 2% when used within the range of pressure from 1 to 1= 2 kbar, homogenization temperature from 200 to 550 C, temperature from 550 to 850 C, and composition from 5 to 26 wt.% NaCl.