If equilibrium is to be achieved, opposing reactions must take place in a closed system at the same rate. The two reactions, known as forward and reverse reactions, shown by a general reaction such as:
A + B C
When the forward and reverse reactions are taking place at the same rate, the system is said to be in a state of “dynamic equilibrium”. During such a state, the macroscopic properties of the system show no change despite changes that occur at the molecular level.
This activity models an equilibrium reaction. The reactants and products are represented by macaroni. The number of macaroni exchanged will represent the changes in the concentrations in the equilibrium reaction.