The Spontaneous Transformation from Macrocrystalline to Microcrystalline Phases at Low Temperatures. The Heat Capacity of MgSO₄·6H₂O¹

Experimentally Determined Standard Thermodynamic Properties of Synthetic MgSO4·4H2O (Starkeyite) and MgSO4·3H2O: A Revised Internally Consistent Thermodynamic Data Set for Magnesium Sulfate Hydrates

“…The magnitude of the error introduced by this assumption is not known exactly but is likely not large, because the temperature range spanned is less than 100 K wide. Nevertheless, now we have experimental data for the important Mg-sulfate hydrates kieserite (Frost et al, 1957), starkeyite (this study), hexahydrite (Cox et al, 1955), and epsomite (Gurevich et al, 2007). For starkeyite, the data reported in this study in the temperature region T = 229-303 K (cf.…”

Internally consistent thermodynamic data for magnesium sulfate hydrates

“…The measured values for the material synthesized by Cox et al (1955) show an unusual deviation from expected behaviour, reminiscent of a transformation spread over a large temperature range (cf. Archer and Rard, 1998).…”

“…Heat capacity data for hexahydrite were presented by Cox et al (1955) and questioned by Archer and Rard (1998). The measured values for the material synthesized by Cox et al (1955) show an unusual deviation from expected behaviour, reminiscent of a transformation spread over a large temperature range (cf.…”

“…For S 0 298 (kieserite), Frost et al (1957) reported a value of 126.36 Jmol À1 K À1 which was obtained by significant graphical extrapolation of their heat capacity measurements above about 150 K; this value was included by Wagman et al (1982) and DeKock (1986). The entropy values for sanderite and starkeyite (DeKock, 1986) are estimates, while S 0 298 (hexahydrite) was obviously taken from Cox et al (1955) in all data collections. Pabalan and Pitzer (1987) calculated mineral solubilities in binary and ternary electrolyte mixtures using available thermodynamic data for solids and aqueous solutions.…”

Rheological and Thermal Properties of Icy Materials

“…Crystalline materials usually have higher thermal conductivity at low and medium temperatures (which are the temperatures of interest for studies of icy satellites) than at high. This is because at low temperatures there are longer mean free paths at lower amplitudes and (2008); THF-sII (tetrahydrofuran structure II clathrate) and EO-sI (ethylene oxide structure I) are from White and MacLean (1985), CH 4 -sI is from Waite et al (2007); NS10-r is from Brodale and Giauque (1958); MS6-r is from Cox et al (1955); MS7 (MgSO 4 · 7H 2 O, epsomite), NS10 (NaSO 4 · 10H 2 O, mirabilite), NC10 (Na 2 CO 3 · 10H 2 O, natron) are from Prieto-Ballesteros and ; FS7 (FeSO 4 · 7H 2 O, melanterite) and CC2 (CaCO 3 ·H 2 O, gypsum) are new data. Data for the last two hydrated salts have been obtained following the same methodology than those published in Prieto-Ballesteros and , by MDSC more harmonicity of the thermal vibrations.…”