The Chemical equilibrium

This model experiment on chemical equilibrium, also known as the piercing experiment, illustrates that a dynamic equilibrium occurs in an apparently quiescent chemical reaction. For this purpose, 2 measuring cylinders are used, one of which is initially filled with water and the other empty. Now water is exchanged between the two measuring cylinders with 2 glass tubes until the filling level in both no longer changes. The students see that after a few cycles an equilibrium is reached in which exactly as much water is transported there as is transported back: This means that despite the mass transfer, the overall reaction appears to be at rest.