You won't need a PhD to run this intuitive yet involved chemical behavior program. SimChemistry displays the behavior of molecules that you build, and explains the actions behind a set of molecular simulations that come with the program (such as how certain gases expand, for example.) While the interface isn't very attractive, it is well designed in that most of the program functions are at your fingertips and easy to use. Which is a good thing, as there's no help file included with SimChemistry. Once you've created a molecule, you can change temperature or pressure conditions in your "virtual" environment and watch what happens. During testing, however, we discovered you can't have more than 500 molecules simultaneously. If you need to add new types, you'll have to delete others. While a 30-day trial isn't nearly enough time to play with all the molecules in the world, it is sufficient to get a sense of how well this program works.
From Charlie Wartnaby:
SimChemistry for Windows uses live onscreen simulation to show how the microscopic behavior of molecules gives rise to macroscopic phenomena in physical chemistry and physics. A collection of ready-made, interactive demo simulations that explore the mixtures are provided. However, the program lets you set up all kinds of simulation systems to see how molecules behave.