作　　者： ; ; ; ; ;

机构地区： 广西大学化学化工学院

出　　处： 《Chinese Journal of Chemical Physics》 2005年第6期1053-1056,共4页

摘　　要： 以Na3PO4·12H2O和ZnSO4·7H2O为原料,采用室温固相反应制备纳米四水磷酸锌,用微量热法研究该反应的反应焓和四水磷酸锌的标准摩尔生成焓.根据Hess定律,设计了一个新的热化学循环:以4mol/LHCl溶液为量热溶剂,用RD496微热量计于298.15K测定了反应物与产物在量热溶剂中的溶解焓分别为(-47.180±0.084)和(-7.617±0.096)kJ/mol,同时测定两种溶液的紫外光谱、折光率和电导率.两种溶液的紫外吸收曲线重叠,稀释500倍后的电导率值分别是2180、2181μS/cm,折光率值分别是1.3679、1.3678.计算出该固相反应的反应焓为-39.530kJ/mol,同时得到纳米四水磷酸锌的标准摩尔生成焓,推荐其值为-4354.004kJ/mol. Nanocrystalline zinc phosphate tetrahydrate was synthesized by solid-state reaction at ambient temperature using Na3PO4 ·12H2O and ZnSO4 · 7H2O as regents. The enthalpy of reaction and the standard enthalpy of formation of zinc phosphate tetrahydrate were studied by microcalorimeter. According to Hess＇s law, a new thermochemical cycle was designed. The dissolution enthalpies of reactant （ △H1 ） and product （△H2） were performed by a RD496 microcalorimeter at 298.15 K using aqueous solution of hydrochloric acid （4mol/L） as a calorimetric solvent. Ultraviolet spectrum, conductivity and refractive index were measured respectively. The results show as follows： △H1 = （ -47. 180± 0. 084） kJ/mol, △H2 = （ -7. 617 ±0. 096 ）kJ/mol. The ultraviolet spectra of the above solution are the same. Conductivity values after 500 times diluted are 2180 and 2181 μs/cm respectively. Refractive indexes are 1. 3679 and 1. 3678 respectively. The standard enthalpy value of the reaction was calculated ： △rHΘ^m = - 39. 530 kJ/mol. The standard enthalpy of formation for zinc phosphate tetrahydrate are recommended -4354. 004 kJ/mol.

关 键 词： 室温固相反应 微热量计 标准摩尔生成焓 纳米 磷酸锌

领　　域： [理学] [理学]