کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
674246 1459552 2012 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Low temperature measurements of the heat capacity and thermodynamic functions of pseudo-malachite Cu5(PO4)2(OH)4
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی جریان سیال و فرایندهای انتقال
پیش نمایش صفحه اول مقاله
Low temperature measurements of the heat capacity and thermodynamic functions of pseudo-malachite Cu5(PO4)2(OH)4
چکیده انگلیسی

The investigation of the heat capacity of a natural specimen of copper phosphate—pseudo-malachite Cu5(PO4)2(OH)4 in the temperature range between 4.2 K and 320 K has been carried out by the method of low-temperature adiabatic calorimetry. Tabulated values of the heat capacity and thermodynamic functions of the mineral including the changes of entropy and enthalpy and the Gibbs function of free energy have been calculated. The standard values of thermodynamic functions of pseudo-malachite at T = 298.15 K are Cp,m°=(385.43±0.41) J mole−1 K−1, Δ0TSm°=(412.16±0.61) J mole−1 K−1, Δ0THm°=(63681.5±57.0) J mole−1, Fm°=(198.57±0.47) J mole−1 K−1. In the low-temperature area 0 < (T/K) < 22.69 an anomaly has been registered in the variation of the heat capacity of the mineral, for which the lattice constituent has been determined. The contribution of anomalous component into entropy and enthalpy of the mineral is ΔStr = (5.772 ± 0.081) J mole−1 K−1, ΔHtr = (29.94 ± 0.42) J mole−1.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Thermochimica Acta - Volume 532, 20 March 2012, Pages 139–144
نویسندگان
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