The dehydration process of Na2MoO42H2O and its kinetics have been studied by TG-DTG. Using Malek method, SB(m,n) was defined as the kinetic model of the dehydration process. The corresponding kinetic and ther-modynami...The dehydration process of Na2MoO42H2O and its kinetics have been studied by TG-DTG. Using Malek method, SB(m,n) was defined as the kinetic model of the dehydration process. The corresponding kinetic and ther-modynamic parameters were obtained.展开更多
Low-temperature heat capacities of the solid compound NaCuAsO4·1.5H2O(s)were measured using a precision automated adiabatic calorimeter over a temperature range of T=78 K to T=390 K.A dehydration process occurr...Low-temperature heat capacities of the solid compound NaCuAsO4·1.5H2O(s)were measured using a precision automated adiabatic calorimeter over a temperature range of T=78 K to T=390 K.A dehydration process occurred in the temperature range of T=368-374 K.The peak temperature of the dehydration was observed to be TD=(371.828±0.146)K by means of the heat-capacity measurement.The molar enthalpy and entropy of the dehydration were ΔDHm=(18.571±0.142)kJ/mol and ΔDSm=(49.946±0.415)J/(K·mol),respectively.The experimental values of heat capacities for the solid(Ⅰ)and the solid-liquid mixture(Ⅱ)were respectively fitted to two polynomial equations by the least square method.The smoothed values of the molar heat capacities and the fundamental thermodynamic functions of the sample relative to the standard reference temperature 298.15 K were tabulated at an interval of 5 K.展开更多
Low-temperature heat capacities of the compound Ni(C4H7O5)2·2H2O(S) have been measured with an auto- mated adiabatic calorimeter. A thermal decomposition or dehydration occurred in 350--369 K. The temperature...Low-temperature heat capacities of the compound Ni(C4H7O5)2·2H2O(S) have been measured with an auto- mated adiabatic calorimeter. A thermal decomposition or dehydration occurred in 350--369 K. The temperature, the enthalpy and entropy of the dehydration were determined to be (368.141 ±0.095) K, (18.809±0.088) kJ·mol ^-1 and (51.093±0.239) J·K^-1·mol^-1 respertively. The experimental values of the molar heat capacities in the temperature regions of 78-350 and 368-390 K were fitted to two polynomial equations of heat capacities (Cp,m) with the reduced temperatures (X), [X=f(T)], by a least squares method, respectively. The smoothed molar heat capacities and thermodynamic functions of the compound were calculated on the basis of the fitted polynomials. The smoothed values of the molar heat capacities and fundamental thermodynamic functions of the sample relative to the standard reference temperature 298.15 K were tabulated with an interval of 5 K.展开更多
基金Project supported by the Natural Science Foundation of Hebei Province (Nos. 202139 202140) and Hebei Education Department (No. 2004325).
文摘The dehydration process of Na2MoO42H2O and its kinetics have been studied by TG-DTG. Using Malek method, SB(m,n) was defined as the kinetic model of the dehydration process. The corresponding kinetic and ther-modynamic parameters were obtained.
基金Supported by the National Natural Science Foundation of China(No.20673050).
文摘Low-temperature heat capacities of the solid compound NaCuAsO4·1.5H2O(s)were measured using a precision automated adiabatic calorimeter over a temperature range of T=78 K to T=390 K.A dehydration process occurred in the temperature range of T=368-374 K.The peak temperature of the dehydration was observed to be TD=(371.828±0.146)K by means of the heat-capacity measurement.The molar enthalpy and entropy of the dehydration were ΔDHm=(18.571±0.142)kJ/mol and ΔDSm=(49.946±0.415)J/(K·mol),respectively.The experimental values of heat capacities for the solid(Ⅰ)and the solid-liquid mixture(Ⅱ)were respectively fitted to two polynomial equations by the least square method.The smoothed values of the molar heat capacities and the fundamental thermodynamic functions of the sample relative to the standard reference temperature 298.15 K were tabulated at an interval of 5 K.
基金Project supported by the National Natural Science Foundation of China (No. 20673050), the Poat-doctor Start-up Foundation of Liaocheng Univer sity (No. 31805).
文摘Low-temperature heat capacities of the compound Ni(C4H7O5)2·2H2O(S) have been measured with an auto- mated adiabatic calorimeter. A thermal decomposition or dehydration occurred in 350--369 K. The temperature, the enthalpy and entropy of the dehydration were determined to be (368.141 ±0.095) K, (18.809±0.088) kJ·mol ^-1 and (51.093±0.239) J·K^-1·mol^-1 respertively. The experimental values of the molar heat capacities in the temperature regions of 78-350 and 368-390 K were fitted to two polynomial equations of heat capacities (Cp,m) with the reduced temperatures (X), [X=f(T)], by a least squares method, respectively. The smoothed molar heat capacities and thermodynamic functions of the compound were calculated on the basis of the fitted polynomials. The smoothed values of the molar heat capacities and fundamental thermodynamic functions of the sample relative to the standard reference temperature 298.15 K were tabulated with an interval of 5 K.