Based on the partition function in statistical thermodynamics, atomic partit ion parameter fi =lg[(ni－1)0.5·Ar,i] is introduced in this paper. The fi has demonstrated good unitarity for all the ground state ato ...Based on the partition function in statistical thermodynamics, atomic partit ion parameter fi =lg[(ni－1)0.5·Ar,i] is introduced in this paper. The fi has demonstrated good unitarity for all the ground state ato ms, and excellent correlativity with the standard entropies (,J·mol－1·K －1) of 70 cations in solid compounds: = －10.247＋27.508 fi , r=0.996. A satisfactory curve equation is developed as follows: =6.229＋13.257 fi1.5, r= 0.999. On the basis of adjacency matrices and fi , a novel partition connectivit y index is developed for the study on the standard entropies of 64 S block compo unds. The linear regression equation is set up by the least square method: =－3 9.416＋33.9610H, r=0.985. The binary linear equation among and 0H, nM (princip al quantum number of the ground state atoms for S block) is drawn up: =－21.591 ＋32.0720H－31.013nM－1, R=0.990. The calculated values of basically tally w ith the experiment values. fi and 0H demonstrate that the method possesses the a dvantage of easy computation and clear physical significance.展开更多
The vapor pressures of n-butyl carbamate were measured in the temperature range from 372.37 K to 479.27 K and fitted with Antoine equation. The compressibility factor of the vapor was calculated with the Virial equati...The vapor pressures of n-butyl carbamate were measured in the temperature range from 372.37 K to 479.27 K and fitted with Antoine equation. The compressibility factor of the vapor was calculated with the Virial equation and the second virial coefficient was determined by the Vetere model. Then the standard enthalpy of vaporization for n-butyl carbamate was estimated. The heat capacity was measured for the solid state(299.39–324.2 K) and liquid state(336.65–453.21 K) by means of adiabatic calorimeter. The standard enthalpy of formation ΔfH[crystal(cr),298.15 K] and standard entropy S(crystal,298.15 K) of the substance were calculated on the basis of the gas-phase standard enthalpy of formation ΔfH(g,298.15 K)and gas-phase standard entropy S(g,298.15 K), which were estimated by the Benson method. The results are acceptable, validated by a thermochemical cycle.展开更多
This paper presents a new model for the calculation of the standard entropies of solidcomplex silicates as follows.4. =53.63+9914-72.81 J/kmol (R=0.9915, Sd=5.39)Sixty complex silicates have been investigated, and go...This paper presents a new model for the calculation of the standard entropies of solidcomplex silicates as follows.4. =53.63+9914-72.81 J/kmol (R=0.9915, Sd=5.39)Sixty complex silicates have been investigated, and good agreement was found between theestimated and experimental entropy values.展开更多
A close relationship has been found between the standard entropies of elements and their electronic configurations. Based on the positions of elements in the periodic table and the variation in the standard entropies ...A close relationship has been found between the standard entropies of elements and their electronic configurations. Based on the positions of elements in the periodic table and the variation in the standard entropies of elements, the standard entropies of elements can be expressed as the sum of two functions: S<sup>0</sup>= f（N） + f（E）, where S<sup>0</sup> is the standard entropy of an element, N the principal quantum number, and E the number of outermost electrons. And the specific formula is S<sup>0</sup>=99.05N<sup>1</sup>/3 + [0.32（sp - 4）<sup>4</sup> - 119.76] + [- 56.56N<sup>1</sup>/3 + 0.70（sd - 7）<sup>2</sup> - 42.12]+[- 11.95 ×10<sup>-4</sup>（df- 8）<sup>4</sup>-105.70], where sp, sd, df are the numbers of the outermost electrons in the sp, sd, df regions of the periodic table, respectively. This formula helps reveal the essence of the standard entropies of elements and deepens our understanding of the thermodynamic characteristics of compounds.展开更多
文摘Based on the partition function in statistical thermodynamics, atomic partit ion parameter fi =lg[(ni－1)0.5·Ar,i] is introduced in this paper. The fi has demonstrated good unitarity for all the ground state ato ms, and excellent correlativity with the standard entropies (,J·mol－1·K －1) of 70 cations in solid compounds: = －10.247＋27.508 fi , r=0.996. A satisfactory curve equation is developed as follows: =6.229＋13.257 fi1.5, r= 0.999. On the basis of adjacency matrices and fi , a novel partition connectivit y index is developed for the study on the standard entropies of 64 S block compo unds. The linear regression equation is set up by the least square method: =－3 9.416＋33.9610H, r=0.985. The binary linear equation among and 0H, nM (princip al quantum number of the ground state atoms for S block) is drawn up: =－21.591 ＋32.0720H－31.013nM－1, R=0.990. The calculated values of basically tally w ith the experiment values. fi and 0H demonstrate that the method possesses the a dvantage of easy computation and clear physical significance.
文摘The vapor pressures of n-butyl carbamate were measured in the temperature range from 372.37 K to 479.27 K and fitted with Antoine equation. The compressibility factor of the vapor was calculated with the Virial equation and the second virial coefficient was determined by the Vetere model. Then the standard enthalpy of vaporization for n-butyl carbamate was estimated. The heat capacity was measured for the solid state(299.39–324.2 K) and liquid state(336.65–453.21 K) by means of adiabatic calorimeter. The standard enthalpy of formation ΔfH[crystal(cr),298.15 K] and standard entropy S(crystal,298.15 K) of the substance were calculated on the basis of the gas-phase standard enthalpy of formation ΔfH(g,298.15 K)and gas-phase standard entropy S(g,298.15 K), which were estimated by the Benson method. The results are acceptable, validated by a thermochemical cycle.
文摘This paper presents a new model for the calculation of the standard entropies of solidcomplex silicates as follows.4. =53.63+9914-72.81 J/kmol (R=0.9915, Sd=5.39)Sixty complex silicates have been investigated, and good agreement was found between theestimated and experimental entropy values.
文摘A close relationship has been found between the standard entropies of elements and their electronic configurations. Based on the positions of elements in the periodic table and the variation in the standard entropies of elements, the standard entropies of elements can be expressed as the sum of two functions: S<sup>0</sup>= f（N） + f（E）, where S<sup>0</sup> is the standard entropy of an element, N the principal quantum number, and E the number of outermost electrons. And the specific formula is S<sup>0</sup>=99.05N<sup>1</sup>/3 + [0.32（sp - 4）<sup>4</sup> - 119.76] + [- 56.56N<sup>1</sup>/3 + 0.70（sd - 7）<sup>2</sup> - 42.12]+[- 11.95 ×10<sup>-4</sup>（df- 8）<sup>4</sup>-105.70], where sp, sd, df are the numbers of the outermost electrons in the sp, sd, df regions of the periodic table, respectively. This formula helps reveal the essence of the standard entropies of elements and deepens our understanding of the thermodynamic characteristics of compounds.
