For a long time I had been working on what I called the universal process. The claim is simple. If you understand a generic process, you understand chemical reactions, state transitions, material relocation, diffusion, and even siphons. They look like different events. Underneath, they are the same shape.
The shape is driven by chemical potential. Wherever there is a difference in chemical potential between one place and another, something will move, and the moving will continue until the difference is closed. A reaction proceeds. A liquid evaporates. A salt spreads through water. Water runs uphill through a siphon and then down. The vocabulary differs from case to case, the apparatus differs, but the engine is the same.
This is why chemical potential is worth the effort it takes to understand. It is not a separate topic alongside reactions and state changes; it is the thing that makes them one topic. Once that is in view, the long list of "kinds of chemical events" collapses into a single process with many faces.
Question
If chemical reactions, diffusion, and a siphon are all the same process, what is the same about them?
Reveal Merrill's answer →Hide answer
Each of them is a movement from a higher chemical potential to a lower one, continuing until the difference is gone. The materials change, the setting changes, the names we give the events change. The shape does not. That shape is the universal process.