Enthalpies of solution of 1,1,3,3-tetramethylurea in normal and branched alkanols (C₂–C₄) at 298.15 K

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• 作者：Evgeniy V. Ivanov ; Vladimir K. Abrosimov ; Valeriy I. Smirnov
• 关键词：Enthalpies of solution ; Tetramethylurea ; Normal and branched alkanols
• 刊名：Journal of Chemical Thermodynamics
• 出版年：2007
• 出版时间：December 2007
• 年：2007
• 卷：39
• 期：12
• 页码：1614-1619
• 全文大小：194 K

文摘

The enthalpies of solution were determined for 1,1,3,3-tetramethylurea in ethanol, 1-propanol, 2-propanol, 1-butanol, and t-butanol (2-methyl-2-propanol). Measurements were made at 298.15 K and molalities m (0.007 to 0.036) mol · kg⁻¹ with a precise isoperibol ampoule-type calorimeter. Standard enthalpies of solution and transfer from one alkanol to the other (including methanol) were calculated. The obvious relationship between the enthalpic and volumetric effects of solution of tetramethylurea in the n-alkanols (C₁–C₄) was discovered. The enthalpic effects of transfer caused by branching of the alkanol molecules, 1-propanol → 2-propanol, and 1-butanol → t-butanol, are opposite in sign and dominated by the configurational changes in the solvation environment of tetramethylurea.