Characteristics of Dynamic Equilibrium

Chemical reactions can occur in either one direction (forward or reverse) or in both directions (forward and reverse). 

Reversible reactions are those that can be reversed in both ways, and you can recognise them by the presence of arrows pointing in both directions, as in the example below.

H2O(l) ⇋ H+(aq) + OH– aq)

Dynamic equilibrium may only exist in reversible processes, and it occurs when the rate of the forward reaction equals the rate of the reverse reaction, which is called the rate of the forward reaction.

 However, because the forward and reverse reactions are still occurring, these equations are considered dynamic.

However, because the two rates are equal and unchanging, they are considered to be in equilibrium.

What is Dynamic Equilibrium and how does it work?

It is possible to describe Dynamic Equilibrium as the condition of a given system in which the reversible reaction taking place in it ceases changing the ratio of reactants to products, but there is still a movement of substances between the reactants and the products, according to the definition. 

This movement occurs at the same pace as the previous movement, and there is no net change in the ratio of reactant to product.

Therefore, when we look at the fields of Physics and Chemistry, we can see that a dynamic equilibrium is most likely to exist after the occurrence of an irreversible reaction.

To put it another way, When the forward and backward processes occur at the same rate in a reversible process, the dynamic equilibrium will be reached in that process. 

There will be no discernible change in the overall system as a result of this. 

Once such a condition has been achieved, the concentrations or partial pressures of all species will remain constant for the foreseeable future.

The equilibrium constants for these sorts of equilibria are depicted with the help of the rate constants for the forward and backward processes, respectively. 

Systems that maintain a dynamic equilibrium are instances of systems that are in steady-state conditions.

Illustrations of Dynamic Equilibrium

A few of the most significant examples of dynamic equilibrium that we encounter in our daily lives are given below.

A precise value for the concentration of carbon dioxide contained in the liquid phase of an aerated drink is assigned to each new bottle of the beverage. 

Following opening the bottle and pouring out half of the contents, the liquid carbon dioxide slowly converts into gaseous carbon dioxide until a new point of equilibrium is reached, and the rate of conversion of CO2 from the gaseous to liquid phase equals the rate of conversion of CO2 from liquid phase to gaseous phase.

Single-phase system in which acetic acid dissociates, resulting in the formation of an acid-base equilibrium.

 The following reaction can be used to explain the state of dynamic equilibrium mentioned above.

 CH3COOH ⇋ CH3COO– + H+ 

It can be detected in the gaseous phase, in the dimerization of nitrogen dioxide, for example. N2O4 is formed as a result of the reaction 2NO2.

As seen in the first example of dynamic equilibrium described above, Henry’s Law holds true in this case, where the equilibrium concentration of carbon dioxide in the liquid phase is proportional to the partial pressure of CO2 gas contained within it.

Haber’s technology is used in the production of ammonia in industry. 

N2 (g) + 3H2 (g) ⇋ 2NH3(g)is the reaction 

Different Types of Equilibrium

In accordance with their characteristics, equilibrium can be divided into three types, which include:

Equilibrium in a Static State

When opposing forces are acting on an object at rest in such a way that the object remains in that position only, the object is said to be in static equilibrium.

 The opposing forces can be internal, external, or a combination of the two forces. The following are some examples of static equilibrium:

• A tree with an apple hanging from it
• A person who is standing on the ground
• A automobile that has been parked in a garage

Equilibrium in a Dynamic Environment

Consider the case of an object travelling at a specific velocity. 

In this case, many external forces are acting on the item in such a way that the sum of the forces is zero.

 According to Newton’s Second Law of Motion, the object continues to move with the same velocity even in such circumstances.

 Because the object’s velocity does not vary, it is considered to be in dynamic equilibrium when it does not change.

When equal but opposite torques are applied to a body rotating with uniform angular velocity, the torques cancel each other out, and the body continues to revolve at the same angular velocity as before.

Conclusion

Equatorial equilibrium is achieved when there is no change in the ratio of products to reactants in a reversible reaction, which is defined as a reaction that can run in both directions.

 Due to the fact that the concentrations of products and reactants are constant, the overall picture of chemical equilibrium is static. 

The reaction is flowing in both directions at the same rate in both directions, which indicates that equilibrium is actually a fairly dynamic process when examined in greater detail.

A steady state function is a function that maintains a constant value across time. 

When a system is in a steady state, the behaviour that is currently observed continues into the future.

Consequently, once an equilibrium has been attained in a reaction, the ratio of product to reactant concentrations will remain constant throughout the duration of that reaction.