Equipment for a Laboratory Exercise in Geochemical Kinetics

一套配有热级的显微镜正被用于开发和校准一种简单的、创新的实验室活动，研究矿物溶液反应的温度依赖性（阿伦尼乌斯活化能）。该练习使矿物学/地球化学本科课程的学生能够直接测量不同温度下的反应速率，同时使他们能够观察反应过程中颗粒表面形态的演变。这极大地提高了学生对与地质科学直接相关的化学动力学几个基本原理的理解，包括扩散、反应速率的温度依赖性以及速率限制机制和晶体表面形态之间的关系。实验练习生成动态的（实时的）地球化学速率数据，然后学生们用这些数据来补充传统的定量作业。此外，该设备正用于校准技术上简单得多的演习版本。任何有显微镜、热板、烧杯、温度计和秒表的地质部门都可以完成同样的工作，而不需要大量投资于专用设备。* * * y

9351010 Velbel A suite of microscopes equipped with thermal stages is being used to develop and calibrate a simple, innovative laboratory activity on the temperature dependence (Arrhenius activation energy) of mineral-solution reactions. The exercise is enabling students in undergraduate mineralology/geochemistry courses to directly measure reaction rates at various temperatures while simultaneously allowing them to observe the evolution of grain-surface morphology during the reaction. This is greatly improving student understanding of several basic principles of chemical kinetics directly relevant to the geological sciences, including diffusion, the temperature dependance of reaction rates, and the relationship between rate-limiting mechanisms and crystal-surface morphology. The lab exercise is generating dynamic (real-time) geochemical rate data which students then are using to augment traditional quantitative homework exercises. Furthermore, the equipment is being used to calibrate a technologically much less complicated version of the exercise. Any geology department with microscopes, hot plates, beakers, thermometers, and stopwatches can perform the same exercise without the necessity of massive investments in dedicated equipment. ***y