Explain the physical significance of van der waals,parameters ?
They correct for volume of the molecules and the attractive forces between them.
The van der Waals parameters are physical constants used to describe the interaction between molecules in the van der Waals equation of state. These parameters take into account the size and attractive forces between molecules.
To understand the physical significance of van der Waals parameters, it is necessary to understand the concept of van der Waals forces. These forces are relatively weak intermolecular interactions that arise due to temporary fluctuations in electron distributions in molecules. They are responsible for phenomena such as the condensation of gases into liquids and the adsorption of gases on surfaces.
The first van der Waals parameter, represented by the symbol "a," accounts for the attractive forces between molecules. It quantifies the strength of intermolecular attractions based on the type of molecules involved. Larger values of "a" indicate stronger attractive forces, which tend to cause molecules to be drawn closer together.
The second van der Waals parameter, represented by the symbol "b," accounts for the size of the molecules. It takes into consideration the volume occupied by the molecules themselves. Larger values of "b" indicate larger molecules that occupy more space, resulting in a larger effective volume.
Together, the van der Waals parameters "a" and "b" allow the van der Waals equation of state to approximate real gas behavior more accurately than the ideal gas equation. By incorporating the effects of molecular size and attractive forces, this equation provides a better description of the behavior of gases, especially at high pressures and low temperatures.
To determine the values of the van der Waals parameters for a specific gas, experimental data, such as critical temperature and pressure, can be used. These parameters can also be estimated using molecular parameters, such as molecular size and polarizability, and various empirical methods.
In summary, the van der Waals parameters "a" and "b" play a crucial role in describing intermolecular interactions and molecular size in the context of the van der Waals equation of state. They provide a more realistic representation of gas behavior, particularly at high pressures and low temperatures.