Standard Molar Enthalpies of Formation for the Two Alkali Metal Borates, Na6[B4O5(OH)4]3•8H2O and K4[B10O15(OH)4]

被引：9

作者：

Li, Ping ^{[1
]}

Liu, Zhi-Hong ^{[1
]}

机构：

[1] Shaanxi Univ Normal, Key Lab Macromol Sci Shaanxi Prov, Sch Chem & Mat Sci, Xian 710062, Peoples R China

来源：

JOURNAL OF CHEMICAL AND ENGINEERING DATA | 2011年 / 56卷 / 01期

基金：

中国国家自然科学基金;

关键词：

THERMOCHEMISTRY; POTASSIUM;

D O I：

10.1021/je100931q

中图分类号：

O414.1 [热力学];

学科分类号：

摘要：

Two pure hydrated alkali borates, Na-6[B4O5(OH)(4)](3)center dot 8H(2)O and K-4[B10O15(OH)(4)], have been synthesized under mild hydrothermal conditions and characterized by single X-ray diffraction, infrared spectra, thermogravimetric analysis, differential thermal analysis, and chemical analysis. The enthalpies of solution of Na-6[B4O5(OH)(4)](3)center dot 8H(2)O and K-4[B10O15(OH)(4)] in 1 mol.L-1 HCl(aq) were measured to be (53.37 +/- 0.09) kJ.mol(-1) and (46.61 +/- 0.15) kJ.mol(-1). With the incorporation of the previously determined enthalpies of solution of H3BO3(s) in 1 mol.L-1 HCl(aq) and of NaCl(s) and KCl(s) in (HCl + H3BO3) aqueous solution, together with the standard molar enthalpies of formation of NaCl(s), KCl(s), H3BO3(s), HCl(aq), and H2O(1), the standard molar enthalpies of formation were found to be -(14093.0 +/- 9.7) kJ.mol(-1) for Na-6[B4O5(OH)(4)](3)center dot 8H(2)O and -(8651.0 +/- 8.1) kJ.mol(-1) for K-4[B10O15(OH)(4)] by solution calorimetry.

引用

页码：102 / 105

页数：4

共 13 条

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