6 May 2016

Properties of a system in thermodynamics

Introduction of various properties :

Thermodynamic property is a point function and defines the state of a system. It is independent of the path followed. 

Generally, a thermodynamic property is two types one is macroscopic and another one is microscopic property.

The word microscopic means something like so small that it can only be seen with the use of microscope while macroscopic means either to something that can be seen with the naked eye or large in scale. 

If a system contains a large number of chemical species such as atoms, ions, and molecules, called macroscopic system and the properties which are associated with this system are called macroscopic properties.

Examples: pressure, volume, temperature, composition, density, viscosity, surface tension, refractive index, colour etc.

Extensive properties: 

Extensive properties depend upon the quantity of matter which is contained in the system. 

Extensive property is dependent on mass.

Examples: mass, volume, heat capacity, internal energy, enthalpy, entropy, Gibb's free energy. 

Intensive properties:  

Intensive properties depend upon the amount of the substance which is present in the system.

The intensive property is not dependent on mass.

Examples: temperature, refractive index, density, surface tension, specific heat, freezing point, and boiling point.