Explain classical versus statistical thermodynamics.

Hint:Classical thermodynamics takes a macroscopic approach while statistical thermodynamics has a microscopic approach.Thermodynamics is a branch of science which deals with heat, temperature and the relationship between different forms of energies such as chemical energy, kinetic energy, heat energy etc.

Complete answer:
To understand the behavior of a system and the changes which take place in the system, we have two approaches; the Classical approach which has macroscopic nature and the statistical approach which has a microscopic nature. In the microscopic approach, the analysis is done at the molecular level and then the behavior of all the molecules is added together to determine the behavior of a system.

On the other hand, in the macroscopic approach, the analysis is based on the quantity of the matter; it does not consider the matter at the molecular level. Hence in statistical thermodynamics, a large number of variables are required to describe the system whereas in the case of classical thermodynamics the number of variables required is comparatively smaller.Properties like kinetic energy, velocity and momentum of molecules are required in the case of statistical thermodynamics while properties like pressure, volume and temperature are needed to describe a system of classical thermodynamics.

Note:Classical thermodynamics is based more upon experimental observations whereas statistical thermodynamics is based upon the average behavior of a group of particles.The statistical analysis of any system is much more complex than the classical analysis. This means that the level of mathematics and computations in both approaches is also very different.