The heat capacity and thermodynamic functions of cerussite

Abstract

The heat capacity of natural lead carbonate (cerussite, PbCO 3) has been measured by means of the low-temperature adiabatic calorimetry over the temperature range of (4 to 320) K. Its thermodynamic functions С р ( Т), S( T) and H( T)– H(0) have been calculated over the whole temperature range from the experimental data on the heat capacity. The standard values of the heat capacity and entropy are equal to C p,m ∘ = 87.07 ± 0.09 J · mol −1 · K −1, S m ∘ = 125.45 ± 0.20 J · mol −1 · K −1, respectively. An anomalous deviation of the heat capacity has been registered in the range of (269 to 278) K.