I am in the process of designing a chemical kinetics course for undergraduates. I would like to demonstrate isomerization equilibria, and therefore am looking for a reaction A <-> B fulfilling the following criteria:
- At least one of the reactants has a color;
- The equilibrium is reached in a few minutes so that the color change is easy to follow (not too fast or slow);
- The reaction is safe and could be demonstrated in a beaker on the table;
- The reaction is reversible and e.g. by gentle heating the equilibrium could be shifted easily.
Titration of some weak acids/bases with suitable indicators might also be good, but of course these are not isomerisations and are a bit more complex than a simple A <-> B reaction.
Any creative ideas are welcome. Thanks!