Innovative Techniques in Microscale Chemistry Experiments
Overlooked techniques for performing chemistry experiments can be discovered by adopting a microscale approach. These unique techniques stemming from newly designed microscale equipment are simple, designed based on elementary principles, and capable of enhancing student motivation in performing experiments. They also serve as tools for better understanding chemistry principles. Three innovative techniques are highlighted here.
An attractive experiment for determining the kinetic order of an “iodine clock” reaction can be redesigned using microscale 8-well reaction strips, the “shake-down” method, and the “1248” technique. Essentially, time for the sudden appearance of blue color is determined in sequence by performing four experiments with reactant concentrations varying in a ratio of 1:2:4:8 at the same time altogether
2.“CDS” Technique (Collection of Distillate at the Source)
A traditional distillation setup collects distillate at a certain distance from the boiling source; this results in loss of product, which can be serious if the microscale method is used. By using a special microscale instrument, it is possible to collect distillate immediately after vapor condensation at the boiling source. This is the rationale for the design of the “CDS” technique. The setup not only significantly improves the product yield, but the cooling water used for condensation is recycled. It offers a helpful means to enhance students’ “green awareness.”
3.“Known Sample Calibration” or “Dual Experiment Calibration” Technique
By referring to the literature value of standard heat of combustion instead of specific heat capacity and duplicating the experiment with a known sample, a value of standard heat of combustion of an experimental alkanol can be determined accurately, which corrects practically all heat loss to the surroundings.
KeywordsSpecific Heat Capacity Kinetic Order Standard Enthalpy Vapor Condensation Standard Heat
- Ehrenkranz, D, & Mauch, J (1990). Chemistry microscale, Kendall/Hunt. 2460 Kerper Boulevard, P.O. Box 539 Dubuque Iowa 52004–0539Google Scholar