What is the difference between the equilibrium position and the equilibrium constant of a reaction? Which changes as a result of a change in reactant concentration?

The process of converting a substance (reactant) into another substance (product) with different chemical identities is called a chemical reaction.

A chemical reaction can be reversible or irreversible.

If the reaction involves the formation of a lower energy product from a high energy reactant, the excess energy is released in the form of heat. These reactions are called exothermic. If the reaction involves heat absorption by reactants, it is considered endothermic.

In a reversible reaction, the forward and backward reactions occur simultaneously. The rate of each reaction initially depends on the reactant concentration and conditions. After a certain time, the forward reaction rate becomes equal to that of the backward reaction. This is called a dynamic equilibrium state.

Therefore, the amount of products formed in an equilibrium state will be equal to that broken down into reactants. Once a reaction attains an equilibrium state, there will be no further change in the concentration of reactants or products, and this is called equilibrium concentrations.

The dynamic equilibrium of a reversible chemical reaction can be described qualitatively using the equilibrium position. It defines the moment at which the forward and backward reaction rate becomes equal.

The ratio of the equilibrium concentration of products to that of the reactants is called the equilibrium constant. Therefore, it describes the reaction equilibrium quantitatively. The equilibrium constant is a constant value for a reaction at a particular temperature.

The equilibrium constant K can be calculated as:

$\mathrm{K}=\frac{\left[\mathrm{Pr}\mathrm{ouducts}\right]}{\left[\mathrm{Reac}\tan \mathrm{t}\right]}\mathrm{at}\mathrm{equilibrium}$

The equilibrium position is a set of reactant and product concentrations that describe equilibrium. Therefore, when the reactant concentration is changed, the concentrations at which the reactants reach equilibrium change. Therefore, the equilibrium position changes with reactant concentration.

The equilibrium constant is the ratio of concentrations. When the initial reactant concentration changes, the reactant concentrations at equilibrium change, causing a subsequent change in product concentration. Therefore, the ratio of concentrations and equilibrium constant do not change.

Therefore, the equilibrium position changes with a change in reactant concentration.