对Δ_rH_m~和Δ_rS_m~随温度变化的定性与定量的讨论

在无机化学中常用热力学分析和讨论化学问题 ,有利于提高该课程理论和实际联系。在化学反应的自发性判断式ΔrG0—m(T) =ΔrH0—m-TΔS0—m 中 ,常用ΔrH0—m(2 98.15k)代替ΔrH0—m(T) ,ΔrS0—m(2 98.15k)代替ΔrS0—m(T)进行有关计算 ,既方便又快捷 ,其误差也较小。为此 ,从定性和定量方面对ΔrH0—m 和ΔrS0—m 随温度变化进行讨论 ,以便加深其理解。

A New Competitive Adsorption Isothermal Model of Heavy Metals in Soils

A new competitive adsorption isothermal model(CAIM)was developed for the coexistent and competitive binding of heavy metals to the soil surface.This model extended the earlier adsorption isothermal models by considering more than one kind of ion adsorption on the soil surface.It was compared with the Langmuir model using different conditions, and it was found that CAIM,which was suitable for competitive ion adsorption at the soil solid-liquid surface,had more advantages than the Langmuir model.The new competitive adsorption isothermal model was used to fit the data of heavy metal(Zn and Cd)competitive adsorption by a yellow soil at two temperatures.The results showed that CAIM was appropriate for the competitive adsorption of heavy metals on the soil surface at different temperatures.The fitted parameters of CAIM had explicit physical meaning.The model allowed for the calculation of the standard molar Gibbs free energy change,the standard molar enthalpy change,and the standard molar entropy change of the competitive adsorption of the heavy metals,Zn and Cd,by the yellow soil at two temperatures using the thermodynamic equilibrium constants.

无水钾镁矾类复盐Rb_2Mg_2(SO_4)_3的热化学

用具有恒定温度环境的新型反应热量计,以3mol·L-1HNO3溶液作为量热溶剂,在298.2K条件下,分别测定了反应混合物[Rb2SO4（s）+2Mg2（SO4）3（s）]和生成物Rb2Mg2（SO4）3的摩尔溶解焓变.通过合理的热化学循环,结合其它标准值计算出了标题化合物的标准摩尔生成焓变,其值为-3966.24±0.06kJ·mol-1.

水合高碘酸锌盐溶解反应的热力学性质

用恒温热量计测定了Zn2 HIO6 ·1.2 5H2 O在 3mol·dm- 3HNO3水溶液中的标准摩尔溶解焓变 ,计算出了相应的标准摩尔自由能变与标准摩尔熵变 ,用线性回归分析并修正了用分光光度计在 2 98.5 - 32

《大学化学》教学中应用启发式教学的设计与实践

利用启发式教学理念与教学方法,以《大学化学》教学过程中反应的“标准摩尔焓变”计算过程为实例,阐述启发式教学方法的设计与实践,让学生由传统的被动接受知识到主动的参与到课堂教学过程中,激发学生的学习兴趣和学习积极性,培养学生发现问题、分析问题和解决问题的能力,体现出既“授之以鱼”,又“授之以渔”的教学理念,有效提高教学的质量和教学的效果。

由△_fG^O_(B.m)(或△_fH^O_(B.m))求△_rG^O_m或(△_rH^O_m)公式的正确推导

由△_fG^e_(B·m)(或△_fH^e_(B·m))的“定义”求△_rG^e_m)(或△_rH^e_m)公式的推导法,比通用的由“定义”结合“规定”等推导法严密可信,不仅揭示了问题的本质,而且可节省由于列出大量的稳定单质的△_fG^e_(B·m),△_fH^e_(B·m)数据所浪费的纸张和精力。有利于教学质量的提高。