无水钾镁矾类复盐Rb_2Mg_2(SO_4)_3的热化学

Thermochemical studies on the langbeinite-type double sulfate salt Rb_2Mg_2(SO_4)_3

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.

Using an isoperibol reaction calorimeter at 298.2 K, We measured the standard molar enthalpies of dissolution of mixtures [Rb2 SO4+2 MgSO4] and double salt Rb2 Mg2 (SO4)3 in aqueous 3 mol·L-1HNO3. With appropriate thermochemical cycle and standard chemical data we worked,out the standard molar formation enthalpy of Rb2Mg2(SO4)3 as-3 966. 24±0. 06kJ·mol-1.