Main Difference – Static vs Dynamic Equilibrium
In chemistry, ‘equilibrium’ refers to a state of a chemical reaction where further changes in the composition of the reactant and the product mixture cannot be perceived from an external point of view. However, analyzing what happens inside the mixture would give us an idea whether change actually doesn’t take place or whether it takes place at an equal rate from either side making it seem that real change doesn’t occur. This defines the idea about the two terms discussed here. The dynamic equilibrium is a position where the rate of reactants turning into products and the rate of products turning into reactants are similar or equal whereas static equilibrium is a point where the reaction has come to a halt; here, the reactants no longer turn into products nor the products turn into reactants. The main difference between static and dynamic equilibrium can be identified as the motion of productions and reactions.
What is Dynamic Equilibrium
Imagine that reaction has only reactants to start with. In this case, the reactants will initially react to each other and start to produce the products. As the concentration of the reactants is higher at the beginning, more reactants will be converted into products. However, as the number of product molecules increases, the products will start to break into the reactant molecules again. But since the number of product molecules is fewer than the number of reactant molecules, the rate of reactants being converted into products is higher than the rate of products being converted back into reactants. The process of the conversion of reactants into products is generally known as the forward reaction, and the process of the conversion of the products into reactants is known as the backward reaction. Basically, in a dynamic equilibrium, both forward and backward reactions occur at the same rate even though it is perceived that the number of products and of reactants remain unchanged.
It is also possible for a reaction at equilibrium to respond to external factors by adopting a new point of equilibrium. This action is governed by the Le Chatelier’s Principle. For example, when extra reactants are added into the system, the rate of the forward reaction increases momentarily until a new balance is reached. The same applies when the concentration of the products is increased; the rate of the backward reaction will increase until the new point of equilibrium. Furthermore, reactions at equilibrium are also sensitive towards factors such as temperature and pressure. The rates and the position of equilibrium can be predicted through a calculated figure called the ‘equilibrium constant.’
What is Static Equilibrium
In the case of a static equilibrium, as in a dynamic equilibrium, the number of reactants and the number of products remain the same. However, the reactions itself has come to a halt without any more reactants converting into products and vice versa. This gives the idea of a static condition as the name implies. For example, imagine that reaction started with several reactant molecules and few product molecules. After some time, the reaction will come to a halt. This means that the composition remained the same actually without any interchanges within the mixture.
Generally, irreversible reactions can be considered under this category, as there is no further change taking place within the system. However, this scenario has more meaning when applied in a mechanical sense rather than a chemical one.
Difference Between Static and Dynamic Equilibrium
Dynamic equilibrium is an equilibrium where reactants are converted to products and products are converted to reactants at an equal and constant rate.
Static equilibrium is an equilibrium that occurs when all particles in the reaction are at rest, and there is no motion between reactants and products.
In a dynamic equilibrium, changes occur within the mixture, keeping the total composition the same.
In a static equilibrium, there are no further changes taking place within the mixture.
In a dynamic equilibrium, the rate of the forward reaction is equal to the backward reaction.
In a static equilibrium, both forward and backward reactions have come to a halt.
External view of the mixture
A dynamic equilibrium will not resemble the exact situation taking place in the system.
In contrast, a static equilibrium will represent the exact situation in the mixture.
Dynamic equilibriums are more often discussed within a chemical context.
Static equilibriums are often applied in a mechanical context rather than a chemical context.