用微量热法测定Cr^（3＋）解聚合作用的反应热及热力学性质  

DETERMINATION OF HEAT OF REACTION AND THERMODYNAMIC PROPERTIES ON THE HYDROLYTIC POLYMERIZATION OF CHROMIUM(Ⅲ) ION BY MICROCALORIMETRIC METHOD

作　　者：于秀芳[1] 

机构地区：[1]山东曲阜师范大学化学系

出　　处：《无机化学学报》1995年第3期246-250,共5页Chinese Journal of Inorganic Chemistry

摘　　要：本文用微量量热仪测定了Ｃｒ￣（３＋）在一定条件下的水解聚合作用的反应热，结合戴安邦等的研究工作［４－１０］，求出了不同温度下的水解聚合作用的平衡常数及有关热力学函数．he hydrolytic polymcrization of Cr(3+) was studied with microcalorimctric method. Solution of reaction system contains:0.02 mol· dm(-3) chromium nitrate, 0.2 mol.dm(-3) sodium nitrate and pH = 2.55(chemical equibra),solution kept at 40℃.In every reaction system. reaction processes produce heat,the thermogram were determined using the 2277 Thermal Activity Monitor.From the thermogram.identified heat of reaction at 40℃ for reaction (1) 2Cr(3+)+2H2O Cr[Cr(OH2)](4+)+2H+,=149.4kJ/molfor reaction (2) Cr[Cr(OH)2](4+)+Cr(3+)+2H2O Cr[Cr(OH2)]+ZH',=58.50kJ/molfor reaction(3)Cr[Cr(OH)2]+Cr(3+)+2H2O Cr[Cr(OH)2]+ZH+,=116. 1kJ / molUnder the present experimcntal conditions, the hydrolysis constants obtained arc as follows =-4.38,=-8.36,=-12.34 by the Luo Qinhui,Dai Anbang et al (7. 10).Using the every heat of reaction and hydrolysis constanLs data,according to Gibbs-Hclmlholtz equation and =-RTlnK,we have calculated the equilibrium constants of hydrolytic polymerization and thermodynamic funchon and at different tempcrature.

关 键 词：铬离子 微量热法 反应热 热力学函数 水解聚合 

分 类 号：O614.611[理学—无机化学] O642.11[理学—化学]