(中南大学 化学化工学院，长沙 410083)
摘 要: 采用C80热量仪测量了温度范围为298.15~363.15 K，总碱质量摩尔浓度mT(mNaOH+mNaAl(OH)4)为0.88~6.16 mol/kg，苛性比αK(mT/mNaAl(OH)4)为1.9~5.0，及常压条件下NaOH-NaAl(OH)4-H2O三元溶液体系的比定压热容；建立铝酸钠溶液体系比定压热容与总碱度、苛性比和温度的关系式；用该关系式对文献结果进行计算，比定压热容的计算值与其实验值之间的平均偏差小于0.014。根据测定结果计算研究铝酸钠溶液的表观摩尔比定压热容(cpΦ)随温度、浓度、及1/αK的变化规律。结果表明：铝酸钠溶液的表观摩尔热容cpΦ随温度的变化有一个最大值出现；与体系的1/αK成线性关系。
关键字: 铝酸钠溶液；三元体系；比定压热容；表观摩尔热容
（School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China）
Abstract:The specific heat capacities at constant pressure of alkaline sodium aluminate solutions in NaOH-NaAl(OH)4- H2O system were determined using a commercial calorimeter (Setaram C80) at temperatures ranging from 298.15 K to 363.15 K and constant pressure, where the total alkli molality mT(mNaOH+mNaAl(OH)4) and αK(mT/mNaAl(OH)4) are 0.88−6.16 mol/kg and 1.9−5.0, respectively. The equation of the specific heat capacity as a function of total alkalinity, αK and temperature was constructed for sodium aluminate solution. The error between the results calculated from this equation and experimental values derived from the literature is 0.014. The apparent molar specific heat capacities (cpΦ) for sodium aluminate solution were also calculated, and the results show that the apparent molar specific heat capacities (cpΦ) have a maximum value with the temperature increasing, and that cpΦ is linear varied with the values of 1/αK.
Key words: sodium aluminate solution; ternary system; heat capacity; apparent molar heat capacities
