Significant discrepancies between van't Hoff and calorimetric enthalpies .3.
Significant discrepancies between van't Hoff and calorimetric enthalpies .3.
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DOI：
10.1016/s0301-4622(96)02229-6
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发表时间：
1997-02-28
影响因子：
3.8
通讯作者：
Sturtevant, JM
中科院分区：
文献类型：
--
作者：
Liu, YF;Sturtevant, JM
对溶液中各种可逆反应的研究表明，控制反应平衡常数的温度变化的焓Δ H-vH很少（如果有的话）与温度无关。还发现在大多数情况下，Δ H-vH的值，适当地评估为随温度变化，与在相同实验条件下通过直接量热法测定的焓值Δ H-cal显著不同。在一个持续的搜索之间的Delta H-vH和Delta H-cal协议的反应，我们已经研究了通过等温滴定量热法庚胺与庚酸在十二烷溶液和α-环糊精与庚酸钠在水溶液中的反应。
The study of a wide variety of reversible reactions in solution indicates that the enthalpy, Delta H-vH, which controls the temperature variation of the equilibrium constant for a reaction, can seldom, if ever, be taken to be independent of the temperature. It is also found in most cases that the values for Delta H-vH, properly evaluated as varying with the temperature, differ significantly from the values for the enthalpy, Delta H-cal determined by direct calorimetry under the same experimental conditions. In a continuing search for reactions which show agreement between Delta H-vH and Delta H-cal, we have studied by isothermal titration calorimetry the reactions of heptylamine with heptanoic acid in dodecane solution and of alpha-cyclodextrin with sodium heptanoate in aqueous solution.