# Thermodynamics

Contents

Thermodynamics is a branch of science that deals with the concept of heat and temperature and the inter-conversion of heat and other forms of energy. It mainly deal with the transformation of heat into mechanical work and vice versa.

### (I) Thermodynamic System

An assembly of a very large number of particles having a certain value of pressure, volume and temperature is called a thermodynamic system.

### (II) Surroundings

Every outside the system which can have a direct effect on the system is called its surroundings.

### (III) Thermodynamic Variables

The quantities like pressure (P), volume (V), and temperature (T) which help us to study the behaviour of a thermodynamic system are called thermodynamic variable.

### (IV) Equation Of State

The mathematical relation between the pressure(P), volume(V) and temperature(T) of a thermodynamic system is called its equation of state.

The equation of state for n moles of a ideal gas can be written as PV = nRT.

## Classification Of Thermodynamic System

### (I) Open System

It exchanges both energy and matter, with its surroundings.

### (II) Closed System

It exchanges only energy (not matter) with its surroundings.

### (III) Isolated System

It exchanges neither energy nor matter with its surroundings.