Effective solution chemistry instruction by integrating live pC–pH diagrams into PowerPoint
✍ Scribed by Chetan T. Goudar; Mark A. Nanny
- Book ID
- 101766611
- Publisher
- John Wiley and Sons
- Year
- 2010
- Tongue
- English
- Weight
- 490 KB
- Volume
- 20
- Category
- Article
- ISSN
- 1061-3773
No coin nor oath required. For personal study only.
✦ Synopsis
pC-pH diagrams provide a graphical illustration of chemical speciation as a function of pH and are hence a very effective tool for understanding the chemical system being studied. This understanding can lead to assumptions that simplify problem solving. However, manual construction of pC-pH diagrams for multiprotic systems is cumbersome and is further complicated by non-standard temperature and ionic strength conditions. As a result, construction of pC-pH diagrams can become the focus of classroom teaching rather than their application to solving real-world problems. Students tend to get lost in the complexities of pC-pH diagram construction and often fail to appreciate their value in problem solving. To address this limitation, we have developed interactive pC-pH diagrams for mono, di, and triprotic systems that are all bundled into a single PowerPoint file. The governing equilibrium equations are presented adjacent to the pC-pH diagram which makes the entire process transparent. The diagrams update in real-time when the total concentration and pK a are changed by the user making them universally applicable to any mono, di, or triprotic system. Temperature impact on pK a and the pC-pH diagram can also be examined for some commonly encountered systems. Because of PowerPoint integration, there is no learning curve and specification of pK a is typically all that is required to use these diagrams. A real-world application of these interactive pC-pH diagrams is presented by examining the solution chemistry in therapeutic protein-producing mammalian cell bioreactors. The cause of high bioreactor CO 2 concentration and strategies to overcome it were determined just by using the interactive pC-pH diagrams without resorting to numerical calculations. We believe these easy to use and interactive pC-pH diagrams could be more extensively used for problem solving in the classroom simultaneously enhancing student understanding of the chemical system being studied. The PowerPoint file with the pC-pH diagrams is available free of charge for academic use.