The number of tools available for students to collect data in a Chemistry classroom can be overwhelming. When we think of a classic chemistry classroom, we always think of standard equipment: Beakers, Flasks, Bunsen Burners and more. What we don’t think about are the tools that, while they seem simple, have increible practical applications in the chemistry lab
Several years ago, the state of California adopted new science standards, known as the Next Generation Science Standards (NGSS). These standards created a monumental shift in how science instruction was to take place in the classroom. Rather than traditional classroom standards, NGSS is based on teaching in a three dimensional format, linking together content standards with Science and Engineering Practices and Crosscutting Concepts that go across different science courses. With these standards comes an emphasis on Scientific Inquiry, where students are to challenge their misconceptions and to derive meaning about scientific concepts through data collection and analysis.
In Chemistry, for example, these standards have led to an added emphasis on the study of Energy. In Chemistry, we primarily study changes in energy in physical processes (like dissolving something or melting something) and chemical processes (like a chemical reaction). We do this using an experimental technique known as Calorimetry. In Calorimetry, we do the process in an insulated container, using water as a medium. We measure temperature changes in the water to determine what energy changes took place in the original process. An essential experimental step is to mix the contents to the container, to ensure that the energy changes are distributed evenly. We currently use glass stir rods to do this, but they do not do a great job mixing the solutions evenly. Mixing solutions is not limited to just calorimetry -- we also mix often to dissolve solids in water for chemical use, mix acid/base mixtures in titration studies and much more.
It is with the support of an Excellence in Education Grant that we plan to purchase 8 stir stations. Stir Stations are essentially magnetic plates that plug into an outlet. We place the reaction container directly on the Stir Station plate, and put a magnetic stir bar (which looks like a pill) in the solution. When the Stir Station plate is on, the pill begins to spin rapidly, evenly mixing the solution. As I mentioned earlier, mixing solutions is a standard experimental step in many chemistry procedures (calorimetry, titration, solution development, etc).. Stir Stations are often a standard piece of equipment in most chemistry classroom, but are often built into the hot plate units. Of all of our hot plates, only 2 have the ability to both heat AND stir. Rather than replace all of our hot plates, these stir stations would be added to our equipment inventory and be used across a number of different procedures that we do in Chemistry and AP Chemistry.