THERMODYNAMIC PROPERTIES OF CASSITERITE SNO2(C) AT 0-1500 K

Abstract

Heat capacity of SnO2(c) is measured by adiabatic calorimetry at 13.40-336.88 K. Using these data we calculated the values of heat capacity, entropy, and enthalpy increment for T = 0-336 K and P = 1 bar. These thermodynamic properties have the following values at T = 298.15 K: Cp0 (298.15 K) = 55.24 ± 0.03 J mol -1 K-1, S0(298.15 K) = 51.82 ± 0.07 J mol-1 K-1, H0(298.15 K) - H0(0 K) = 8.806 ± 0.005 kJ mol-1. The H 0(T) - H0 (0 K) SnO2(c) values are adjusted using a new procedure on the basis of original and published data. An equation is proposed for enthalpy increment H 0(T) - H0 (0 K) for T = 336-1500 K. Using this equation, we calculated Cp0 (T), S 0(T), and H0(T) - H0 (0 K) SnO 2(c) for these temperatures.