离子在DMF-水混合溶剂中的体积性质  

Volumetric properties of ions in DMF-water mixtures.

作　　者：许莉[1] 林瑞森[1] 

机构地区：[1]浙江大学化学系,浙江杭州310027

出　　处：《浙江大学学报（理学版）》2003年第1期62-65,共4页Journal of Zhejiang University（Science Edition）

基　　金：国家自然科学基金资助项目(29773041)

摘　　要：利用精密数字密度计测定了298.15K氯化钾及氯化铵在N,N-二甲基甲酰胺(DMF)-水混合溶剂中的密度,计算了氯化钾及氯化铵的表观摩尔体积和极限偏摩尔体积,得到了相关离子的极限偏摩尔体积V(?)和迁移偏摩尔体积△1V(?).结果表明,当DMF浓度为15％～45％时,K+和NH4+的极限偏摩尔体积均表现增加趋势;而Cl-的极限偏摩尔体积在同一DMF浓度范围内则表现为逐渐减小.利用溶质-溶剂和溶剂-溶剂相互作用对结果进行了讨论.Densities of KC1 and NH4C1 in several DMF-water mixtures were measured at 298. 15K with an oscillat-ing-tube densimeter. From these densities, apparent molar volumes and limiting partial molar volumes were calculated. Single-ion partial molar volumes of transfer from water to DMF-water mixtures were also obtained. The experimental result shows that the ionic partial molar volumes of K+ and NH4+ increase with increasing concentration of DMF in the range of 15% to 45%. On the contrary, the ionic partial molar volume of Cl- decreases with increasing concentration of DMF in the same region. The results were discussed on the basis of ion-solvent and solvent-solvent interactions.

关 键 词：离子 DMF-水混合溶剂 体积性质 极限偏摩尔体积 氯化钾 氯化铵 N N-二甲基甲酰胺 

分 类 号：O646.1[理学—物理化学]