Thermodynamics (Part 2)

State of a System

In Thermodynamics, the state of the system is specified by state functions or state variables.

The state of a thermodynamic system is described by its measurable or macroscopic properties. We can describe the state of a gas by quoting its pressure(p), volume(V), temperature(T), amount(n) etc. The variables like p, V, T are called state variables or state functions because their values depend only on the state of the system and not how it is reached. In order to completely define the state of a system it is not necessary to define all the properties of the system as only a certain number of properties can be varied independently.

Properties of a System

The properties of a system can classified in two types :-

1. Extensive Properties

The properties of a system which depend on the mass or the total number of particles in the system are known as Extensive Properties. e.g. Total Energy, Volume.

2. Intensive Properties

The properties of a system which depend on concentration and do not depend on the mass or the total number of particles in the system are known as Intensive Properties. e.g. Pressure, Density, Reactive Index.