Thermodynamics of aqueous adenine: Standard partial molar volumes and heat capacities of adenine, adeninium chloride, and sodium adeninate from T = 283.15 K to 363.15 K

CHNOSZ: Thermodynamic Calculations and Diagrams for Geochemistry

“…Although there is considerable overlap with the slop16.dat update for SUPCRT92 (Shock, 2016), OBIGT uses different data sources for aqueous Al species (Tagirov and Schott, 2001), As species (Nordstrom and Archer, 2003), Au, Ag, and Cu species Zotov, 2001, 2010), Pd species (Tagirov et al, 2013), Zn species (Akinfiev and Tagirov, 2014), and Pt species (Tagirov et al, 2015). Other notable differences are the inclusion of goethite, other Fe-oxyhydroxides, and evaporite minerals (Majzlan et al, 2003;Grevel and Majzlan, 2009), aqueous phenanthrene and methylphenanthrene isomers , experimentally derived HKF parameters for aqueous adenine (Lowe et al, 2017), and all of the organic compounds reported by Helgeson et al (1998) and Richard and Helgeson (1998).…”

“…The function named EOSregress facilitates this process by combining calculations of the properties of water with regressions using the linear model functionality of R. The vignette "Regressing Thermodynamic Data" demonstrates this capability and outlines an iterative method to account for the T and P dependence of the Born coefficient (ω) for charged species in the revised HKF equations. The regression functions were used in a recent study to regress HKF parameters for aqueous adenine from experimental data (Lowe et al, 2017).…”

“…These and many other calculations are becoming more tractable through the expansion of thermodynamic databases to include more organic and biochemical species at greater ranges of temperature and pressure (Shock and Helgeson, 1990;Shock, 1995;Amend and Helgeson, 1997;Helgeson et al, 1998;Richard and Helgeson, 1998;Dick et al, 2006;LaRowe and Helgeson, 2006a,b;LaRowe and Dick, 2012;Kitadai, 2014;Canovas and Shock, 2016;Lowe et al, 2017;Azadi et al, 2019). However, there are limited choices of software packages for thermodynamic calculations and diagrams commonly used in hydrothermal geochemistry.…”

Standard Partial Molar Heat Capacities and Volumes of Aqueous N,N-Dimethylethanolamine and N,N-Dimethylethanolammonium Chloride from 283.15 to 393.15 K, and Ionization Constants to 598.15 K

“…With the development of twin fixed-cell, power-compensation, differential-temperature scanning nanocalorimeters, it has become possible to measure the apparent molar heat capacities of dilute solutions at temperatures as high as 430 K, using methods pioneered by Earl Woolley and his co-workers at Brigham Young University. , This paper reports densities and heat capacities, measured relative to water, from 283.15 to 363.15 and 393.15 K, respectively, for dilute aqueous solutions of N , N -dimethylethanolamine and N , N -dimethylethanolammonium chloride using methods reported in earlier papers. , Apparent molar volumes, V ϕ , and heat capacities, C p,ϕ , were calculated from these measurements and corrected for speciation to obtain standard partial molar properties V ° and C p ° , for the species DMEA­(aq) and DMEAH + Cl – (aq). The semiempirical “density” model of Mesmer et al was fitted to the experimental values for V ° and C p ° , measured in this work and the high temperature values reported by Bulemela and Tremaine over the range 423.15 to 598.15 K. The fitted parameters were used, with literature values for the standard Gibbs energy and enthalpy of ionization at 298.15 K, to calculate values for the ionization constant of DMEA from 283.15 to 598.15 K at steam saturation pressures.…”

“…24,25 This paper reports densities and heat capacities, measured relative to water, from 283.15 to 363.15 and 393.15 K, respectively, for dilute aqueous solutions of N,N-dimethylethanolamine and N,N-dimethylethanolammonium chloride using methods reported in earlier papers. 26,27 Apparent molar volumes, V ϕ , and heat capacities, C p,ϕ , were calculated from these measurements and corrected for speciation to obtain standard partial molar properties V°and C p °, for the species DMEA(aq) and DMEAH + Cl − (aq). The semiempirical "density" model of Mesmer et al 19 1.…”