Thermodynamic Equilibrium and It’s Type [With PDF]

Thermodynamic Equilibrium pdf

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Let’s Understand What is Thermodynamic Equilibrium?

The term “Thermodynamic” means it is a branch of physics that deals with the heat, work, and form of energy.

The term “Equilibrium” means the state of balance of system within itself and between system and surrounding.

Today we are going to study Thermodynamic Equilibrium and It’s Type.

Note: At the end of the articles you can find PDF that you can download.

Thermodynamic Equilibrium:

Thermodynamic equilibrium is defined as, (When we heard words Thermodynamic Equilibrium that means Balance of Energy, work, and heat.)

The system is said to be thermodynamic equilibrium when no spontaneous change in any macroscopic property is observed as the system is isolated from its surroundings.

Types of Thermodynamic Equilibrium:

There is a total 3 thermodynamic equilibrium which are:

  • Chemical Equilibrium
  • Mechanical Equilibrium and
  • Thermal Equilibrium:

Chemical Equilibrium:

A system is said to be chemical equilibrium when no chemical reaction takes place in the system or between system and surrounding.

The chemical composition will be the same throughout the system and this will not vary that system in chemical equilibrium.

This is a reversible reaction.


CaCO→ CaO + CO

When we heat Calcium Carbonate (CaCO3 ) at temperature 1073K will get CaO and CO

Mechanical Equilibrium:

A system is said to be mechanical equilibrium when there is no unbalanced force within the system or between system and surroundings.

It deals with the force.

The pressure in the system is the same at all points and does not change with respect to time.


Treadmill: This is a gym instrument on which we run but we don move forward because the force you trying to push forward the same force acting opposite to push backward. So this is one of the best examples of mechanical equilibrium.

Thermal Equilibrium:

A system is said to be thermal equilibrium when there is no temperature difference present and the temperature remains equal at all point.

Thermodynamic Equilibrium pdf
Thermal Equilibrium


A hot cup of tea has a higher temperature as compared to surrounding so this is not in thermal equilibrium.

But when you keep this for a duration, till the temperature emits by radiation process to the environment and the surrounding temperature and a cup of tea temperature remains the same at that moment we can say this is in thermal equilibrium.