What is Chemical equilibrium in Chemistry?

Chemical equilibrium in Chemistry is a state in chemical system when the rate of forward reaction is equal to the rate of backward reaction.

When the rate of forward reaction equals the rate of backward reaction, it means also that the concentrations of reactants and products will remain constant but not necessarily the same.

Chemical equilibrium in Chemistry is only attained in chemical reactions and does not just exist and there are little misunderstanding between the concept of chemical equilibrium and rates of reaction.

While chemical equilibrium deals with the maximum yield of products in respect to which side of the reaction will be favoured in chemical reaction, chemical kinetics (rates of reactions) deals with how fast or slow a reaction could go though there are similarities like factors affecting both rates of reaction and chemical equilibrium.

Moreover, in chemical equilibrium when external constraints are imposed you need to understand whether the reaction will shift to left or right by studying the behaviors of chemical reactions in equikibrium.

When is a reversible reaction said to be in dynamic equilibrium?

It is important to understand that the type of equilibrium in Chemistry we focus on is dynamic equilibrium.

A chemical resection is said to be in dynamic equilibrium when the rate of forward reaction equals the rate of backward reaction in such a way that the concentrations of reactants and products remains constant.

There is a need to fully understand the concept of dynamic equilibrium in chemistry and feature of a system in dynamic equilibrium .

Dynamic equilibrium indicates an equilibrium that is temporal and can be altered in a chemical reaction. These reactions are altered when there are external constraints like change in Temperature, pressure or concentration imposed on the system.

Properties of a system in dynamic chemical equilibrium

1.The rate of reaction equals the rate of backward reaction

2. The concentrations of reactants and product remains constant

3.The chemical reaction must be reversible

4. The reaction must occur in a closed system

5. The amount of reactants and products do not necessarily need to be equal

6. A catalyst do not affect the chemical equilibrium position of the reaction

What causes changes in chemical equilibrium in chemistry?

In chemical equilibrium in Chemistry, there are changes that cause equilibrium to shift to the left or right and thus cause temporarily changes in equilibrium.

This statement is boldly supported by Le Chatelier principle and which states that when an external constraint like change in Temperature. Pressure and Concentration is imposed on a system in equilibrium, the equilibrium position will shift in order to annul or neutralize the constraint.

I will briefly talk about how these changes can cause equilibrium to shift to either left or right.

External constraint	How this external constraint will shift.
Effect of Temperature	CaCO3 ==> CaO + CO2    Enthalpy change = +ve   What is the effect of increase in temperature on equilibrium? The equilibrium position will shift to the right.   Reason: Because forward reaction is endothermic
What is the effect of decrease in temperature on equilibrium? The equilibrium position will shift to the left   Reason: Because since forward reaction is endothermic, backward reaction is exothermic.
Effect of Pressure	2N2 + H2 ==> 2NH3 What is the effect of increase in pressure on equilibrium? The equilibrium position will shift to the right.   Reason: Because side with a smaller number of moles is favoured
What is the effect of decrease in pressure on equilibrium? The equilibrium position will shift to the right.   Reason: Because the side with higher number of moles is favored
Effect of Concentration	Mg + Cl2 ==> MgCl2 What is the effect of adding more of Mg on equilibrium? The equilibrium position will shift to the right.   Reason: Because equilibrium will shift to produce more of the side with less concentration
What is the effect of decrease in Mg on equilibrium? The equilibrium position will shift to the left.   Reason: Because equilibrium will shift to produce more of the side with less concentration
Effect of catalyst	A catalyst has no effect on equilibrium position although it increases the rate of favored reaction

So chemical equilibrium in chemistry focuses mainly on the dynamic equilibrium which exists when the rate of forward reaction equals the rate of backward reaction in such a way that the concentrations of reactants and products remains constant.