电导法测定298.15K时硫酸氧钒离子对解离常数  

Determination of the Vanadyl Sulfate Ion-Pair Dissociation Constant at 298.15 K Using Electric Conductivity

作　　者：张书弟[1] 翟玉春[1] 严川伟[2] 

机构地区：[1]东北大学材料与冶金学院,辽宁沈阳110819 [2]中国科学院金属研究所金属腐蚀与防护国家重点实验室,辽宁沈阳110016

出　　处：《东北大学学报（自然科学版）》2012年第9期1311-1314,共4页Journal of Northeastern University(Natural Science)

基　　金：国家自然科学基金资助项目(21003141)

摘　　要：为优化钒电池电解液配比和设置合理的充放电制度,需弄清自由钒离子活度和离子对的解离常数及其热力学性质.研究了电导法测定在298.15 K时水溶液中VOSO4.3.53H2O(s)的电导率,利用Origin数据拟合求出极限摩尔电导;采用改进的Ostwald稀释定律和改进的Davies方程求解活度系数,进而求得溶液的真实离子强度;采用Fuoss方法求解硫酸氧钒离子对的解离常数.经过数据处理得到298.15 K时硫酸氧钒极限摩尔电导率Λ0为203.2520325 S.dm2.mol-1,硫酸氧钒离子对的解离常数Kd为0.001 961 62,为电池性能有关的热力学性质提供了基础数据.To optimize electrolyte ratio of the vanadium redox flow battery and set a reasonable charge and discharge system, the free vanadium ion activity, ion-pair dissociation constant and other thermodynamic properties should be clarified. The conductivity of the VOSO4· 3.53H20（s） in aqueous solution was determined using the electric conductivity method at 298. 15 K. The limiting molar conductance was obtained using the Origin data fitting and then the activity coefficient was solved with the improved Ostwald dilution law and the Davies equation, so as to obtain the true solution ionic strength. The vanadyl sulfate ion-pair dissociation constant was calculated through the Fuoss method. The vanadyl sulfate limiting molar conductance A0 is 203.252 032 5 S-dm2· mol 1 and the vanadyl sulfate ion-pair dissociation constant K（d is 0.001 961 62, which may provide a basic data for the battery thermodynamic properties.

关 键 词：钒氧化还原液流电池 硫酸氧钒 电导法 解离常数 水溶液 

分 类 号：O645.1[理学—物理化学]