Thermochemistry of the solution of ¦Â-alanine in (H₂O + alcohol) mixtures at 298.15 K

详细信息    查看全文

• 作者：Valeriy I. Smirnov ; Valentin G. Badelin
• 关键词：Amino acids ; H2O ; Alcohols ; Enthalpy of solution ; Enthalpy of transfer ; Mixed solvent
• 刊名：Thermochimica Acta
• 出版年：2013
• 出版时间：10 August, 2013
• 年：2013
• 卷：565
• 期：Complete
• 页码：202-204
• 全文大小：584 K

文摘

The enthalpies of the solution of ¦Â-alanine in H₂O + (methanol, ethanol, 1-propanol and 2-propanol) mixtures with alcohol content up to 0.4 mol fractions, have been determined calorimetrically at T = 298.15 K. The standard enthalpies of the solution and transfer of ¦Â-alanine from water to aqueous alcohol have been calculated. The effect of structure properties of a mixed solvent on specified enthalpy characteristics of ¦Â-alanine is discussed. The enthalpy coefficients of pairwise interactions between ¦Â-alanine and alcohol molecules have been computed. It has been found that these coefficients become increasingly positive in methanol, ethanol, 1-propanol, and 2-propanol sequence. A comparative analysis of thermodynamic characteristics of dissolution of ¦Â-alanine and d,l-¦Á-alanine in the mixtures studied has been made.