ERRORS IN THE EVALUATION OF ARRHENIUS AND VANTHOFF PLOTS
ERRORS IN THE EVALUATION OF ARRHENIUS AND VANTHOFF PLOTS
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DOI：
10.1042/bj2090277
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发表时间：
1983-01-01
影响因子：
4.1
通讯作者：
KELETI, T
中科院分区：
文献类型：
--
作者：
KELETI, T
分别从Arrhenius图或Van't霍夫图计算的活化或正常熵、熵和自由熵的数值中的误差是由于忽略方程中的等维性或不适当的近似。应避免量纲化，如果反应中发生摩尔数变化，则需要使用相对浓度。只有当反应遵循最简单的米氏机理时，用Vmax/ET代替产物形成的速率常数来应用阿克里尼乌斯图才有意义;然而，即使在后一种情况下，用Km来应用范特霍夫图也是值得怀疑的。
Errors in the numerical values of activation or normal enthalpies, entropies and free enthalpies calculated from Arrhenius or van''t Hoff plots, respectively, are due to the neglect of equidimensionality in equations, or to inappropriate approximations. The logarithmization of dimensioned quantities should be avoided, which demands the use of relative concentrations if a change in mole number occurs in the reaction. The application of the Arrhenius plot to enzymic reactions by using Vmax/ET instead of the rate constant of product formation has meaning only if the reaction follows the simplest Michaelis-Menten mechanism; however, the use of the van''t Hoff plot using Km is questionable even in the latter case.