应用钠β氧化铝测量Na-Pb合金的热力学性质

Thermodynamic properties of Na Pb alloys by using a sodium beta-alumina

应用Na|Na+ β Al2 O3|NaxPb1-x固体电解质电池测定了 42个Na/NaxPb1-x(x =0 .0 43～ 0 .9878)电池在 5 0 8～ 6 48K的电动势。计算了钠 /高铅钠合金 (液 ,x =0 .0 43～ 0 .6 )电池电动势及其温度系数 ,钠在合金中的活度系数、偏摩尔熵 S(Na)、偏摩尔焓 H(Na)和x(Na)的关系。热力学函数对钠摩尔分数的线性关系 ,相应于在钠铅相图中的富铅相界、共晶体NaPb4 ,NaPb NaPb3 和化合物NaPb组分处产生的偏折 ,表征液态钠铅合金存在着类似于固相结构的化学络合物。根据电池电动势对组分和温度的关系 ,测量了合金的熔化温度及NaPb4 ,NaPb NaPb3,NaPb Na9Pb4

EMFs of forty two Na/Na x Pb 1- x ( x =0.043?33～0.987?8) cells were measured by using a Na｜Na + β Al 2O 3｜Na x Pb 1- x solid electrolyte cell. The EMF and its temperature coefficient of the Na/Na x Pb 1- x (liquid), activity coefficient of the sodium in Na x Pb 1- x , sodium partial molar entropy (Na) and partial molar enthalpy (Na) were also calculated as a function of x (Na). For the liquid Na/Na x Pb 1- x cell, the linear relationship between d E /d T , (Na), (Na) and x (Na), respectively, were deflected at x (Na)= 0.083, 0.20, 0.39, 0.48, 0.52 which correspond to the rich lead phase, NaPb 4 entectic point, NaPb NaPb 3 entictic point and NaPb compound analogous to transformation of phase region in the Na Pb system. The results indicate that chemical complex exist in the molten Na x Pb 1- x near the temperature of liquids line in Na Pb phase diagram. The molting temperatures of Na Pb alloys and entectic temperatures of NaPb 4 , NaPb NaPb 3 and NaPb Na 4Pb 9 have been determined from the dependence of the cell EMF on component and temperature.[