Enthalpy of formation of natural hydrous copper sulfate: Chalcanthite

Low-temperature heat capacity and thermodynamic functions of natural chalcanthite

“…The weighed portion of the sample, taken up to the 5th decimal place, was subjected to drying in a dessicator for several weeks. In a previous work [50], it was found that the loss of first molecule of crystallization water starts as early as at 40-50°C. Moreover, the pressure of water vapor over crystalline hydrate CuSO 4 Á5H 2 O, at which the first cleavage of a water molecule starts is 4.85 mmHg at 20°C.…”

“…Resolution 133 eV at 5.9 keV (Mn-cathode), the resolution in the secondary electrons (SEI mode) 7 nm, magnification from 40 to 360,000, the probe current 10 À12 -10 À5 A, accelerating voltage 1-50 kV, the elements analyzed: from boron to uranium. A more detailed description of the research of the composition and structure of the samples studied were presented in a previous paper [50].…”

On the optimization of the crystallization related to an aqueous copper sulfate (CuSO4.5H2O)

“…1996; Bissengaliyeva et al. 2016). In industrial level, it is produced through the reaction of metallic copper with a hot concentrated sulfuric acid in the bubbling of an air oxidant (Richardson 1997).…”

“…Copper sulfate (CuSO 4 .5H 2 O) has found many areas of applications such as agriculture, antiseptic agent, electroplating processes, electronics as an intermediate, antifungal agent, treatment of copper deficiency, and even catalyst in petrochemical processes (Giulietti et al 1996;Bissengaliyeva et al 2016). In industrial level, it is produced through the reaction of metallic copper with a hot concentrated sulfuric acid in the bubbling of an air oxidant (Richardson 1997).…”

“…Thermochemical characterization of natural chalcanthite and synthetic hydrous copper sulfate (blue vitriol) by using the melt solution calorimetry in accordance with Hess's laws shows that the standard molar enthalpies of formation were −(2267.2 ± 4.1) kJ.mol −1 for natural chalcanthite and −(2272.6 ± 6.0) kJ.mol −1 for synthetic hydrous copper sulfate (blue vitriol) at Δ f H 0 m ( T = 298.15 K) which can be used the quantitative modeling of the physicochemical conditions related to crystallization (Bissengaliyeva et al. 2016).…”