In her blog Stoichiometry Resources Deanna Cullen mentions using PhET simulations based out of the University of Colorado at Boulder. I too made certain simulations a part of my high school chemistry curriculum, in particular, the Gas Properties simulator. In previous years, I would schedule, amongst the multiple english classes, a trip to the computer lab and have my students interact with this simulation. When I had the opportunity to go 1:1 with iPads in my classroom I had already given up trying to schedule any more time in the computer labs due to an increase in the number of English classes and continued to be at a disadvantage because of a incompatibility issue between the program needed to run the PhET simulations and what was available on the iPad.
However, I recently came across a free app entitled iGasLaw by Cognitive Efficieny, Inc that has provided me and my students with some of the useful tools that were so valuable with the PhET Gas Properties simulator. With this app, students have the capability on the iPad to adjust or hold constant variables such as volume, temperature, and pressure and then see what that effect has on the other variables. I recommend if your teaching your students about the relationship between gas laws to download the app and check it out.
Another app that has been very convenient for allowing students to discover the relationship of Boyle’s Law and Charles Law is the free app that can be downloaded and used on the iPad entitled Gas Laws HD Lite by Tj Fletcher. This app is great if you don’t have a set of syringes to use as a means of measuring volume and pressure. Units available in the app for pressure include atm, kPa, or mmHg and a simulated digital measuring device is included. A quick slide of your finger back and forth on the syringe changes the volume of the gas in the syringe and as a result the pressure exerted by the gas is displayed. Pair this up with a nice graphing app and a nice graph showing the relationship between pressure and volume and volume and temperature can be displayed quickly. A similar simulation is also used for showing Charles Law.