First and second dissociation constants of deuterio-o-phthalic acid in D2O from 5 to 50�C
作者:Yung Chi Wu、William F. Koch
DOI:10.1007/bf00644891
日期:1986.6
and second dissociation constants of deuterio-o-phthalic acid in deuterium oxide have been determined by the emf method over the temperature range of 5 to 50°C. The pD values for potassium deuterium phthalate have been calculated from these two constants and experimentally verified. The thermodynamic properties for the dissociation of deuterio-o-phthalic acid have been evaluated. At 25°C, these values
氘代邻苯二甲酸在氧化氘中的第一和第二解离常数已通过电动势方法在 5 至 50°C 的温度范围内确定。邻苯二甲酸氘钾的 pD 值已从这两个常数计算出来并经过实验验证。已经评估了氘代邻苯二甲酸解离的热力学性质。在 25°C 下,摩尔浓度标度中的这些值是:pK1A=3.505、pK2A=5.890 和 pD=4.518。从 K1A 和 K2A 分别得出:ΔGo=20.003, 33.582 kJ-mol−1;ΔHo=2.851, 2.208 kJ-mol−1;ΔSo=-76.7,-105.2 J-mol-1-K-1;并且ΔCpo=-52.7,-315.6 J-mol-1-K-1。讨论了同位素效应。