Sucrose Hydrolysis-Temperature Dependence of the Activation Energy

摘要

Sucrose hydrolysis is often cited as one of the classic examples of a chemical reaction with a temperature-dependent aactivation enery. Two different investigators, Moelwyn-Hughes (polarimetry) and Leininger and Kilpatrick (dilatometry), both claimed that the energy of activation decreased with increasing temperture. A less-cited paper by Heidt and SPurvis claimed that the energy of activation was temperature independent. More recently, Kubler and co-workers at Furman University remeasured sucrose hydrolysis polarimetrically with correction made for the mutarotation lag and also concluded that the energy of activation die dnot vary with temlperature. Recent interest in the measurement and interpretation of heat capacities of activation has led to more rigorous methods of detecting temperature varient activation parameters. One such method by Blandamer, Robertson, and co-workers was applied to the sucrose hydrolysis data of Molwyn-Hughes and Leininger and Kilpatrick. It was found that the data did not support the inclusion of a temperature-dependent activation energy. Blandamer's method applied to Kubler's data also confirms the absence of any need to include temperature-dependent activation parameters.