配合物Zn(Met)SO_4·H_2O(s)的低温热容和标准摩尔生成焓  

Low-Temperature Heat Capacities and Standard Molar Enthalpy of Formation of Complex Zn(Met)SO_4·H_2O(s)

作　　者：邸友莹[1] 高胜利[2] 谭志诚[3] 孙立贤[3] 

机构地区：[1]聊城大学化学化工学院,聊城252059 [2]西北大学化学系,西安710069 [3]中国科学院大连化学物理研究所热化学实验室,大连116023

出　　处：《化学学报》2007年第14期1299-1304,共6页Acta Chimica Sinica

基　　金：国家自然科学基金(No.20673050);聊城大学博士后启动基金(No.31805)资助项目

摘　　要：利用精密自动绝热热量计直接测定了配合物Zn(Met)SO4·H2O(s)在78～370K温区的摩尔热容.通过热容曲线的解析得到该配合物的起始脱水温度为T0=329.50K.将该温区的摩尔热容实验值用最小二乘法拟合得到摩尔热容(Cp,m)对温度(T)的多项式方程,并且在此基础上计算出了它的舒平热容值和各种热力学函数值.依据Hess定律,通过设计热化学循环,选择体积为100cm3、浓度为2mol·L-1的盐酸作为量热溶剂,利用等温环境溶解-反应热量计,测定和推算出该配合物的标准摩尔生成焓为?fHms=-(2069.30±0.74)kJ·mol-1.Low-temperature heat capacities of complex Zn（Met）SO4·H2O（s） have been precisely measured with a small sample precision automated adiabatic calorimeter over the temperature range from 78 to 370 K. The initial dehydration temperature of the complex （T0=329.50 K） has been obtained by means of the analysis of a heat capacity curve. The experimental values of molar heat capacities have been fitted to a polynomial equation of heat capacities （Cp,m） vs. the temperature （T） with the least square method. The smoothed heat capacities and the thermodynamic functions of the complex have been calculated on the basis of the equation. In accordance with Hess law, the standard molar enthalpy of formation for the complex was determined as △fHm^⊙=-（2069.30±0.74）kJ·mol^-1, by using an isoperibol solution-reaction calorimeter, designing a thermochemical cycle and choosing 100 mL of 2 mol·dm^-3 HCl as calorimetric solvent.

关 键 词：Zn(Met)SO4·H2O(s) 绝热量热法 低温热容 溶解-反应量热法 标准摩尔生成焓 

分 类 号：O641.4[理学—物理化学]