# Van Der Waals EOS Shortcomings & Corrections

• Krishna0703
In summary, the Van Der Waals equation of state is a thermodynamic equation that describes the behavior of real gases, taking into account their size and intermolecular forces. However, it has limitations as it does not accurately describe high pressure or low temperature conditions and assumes ideal gas behavior. These shortcomings can be corrected by introducing correction factors such as the compressibility factor. Other equations of state such as the Redlich-Kwong, Peng-Robinson, and Soave-Redlich-Kwong have been developed to better account for non-ideal gas behavior.

#### Krishna0703

what are the main drawbacks of the van der waals equation of state for real gases and how are they corrected?

I have successfully used the van der Waals equation of state for numerous practical calculations that don't require extreme accuracy. Considering ease-of-use, it is one of the better mechanistic models available.

## 1. What is the Van Der Waals equation of state and what does it describe?

The Van Der Waals equation of state is a thermodynamic equation that describes the behavior of real gases, taking into account their size and intermolecular forces. It predicts the relationship between pressure, volume, and temperature for a gas at a given state.

## 2. What are some limitations of the Van Der Waals equation of state?

The Van Der Waals equation of state does not accurately describe the behavior of gases at high pressures or low temperatures, as it does not take into account the non-ideal behavior of real gases. It also assumes that the gas molecules have no volume and do not interact with each other, which is not the case in reality.

## 3. How are these shortcomings of the Van Der Waals equation of state corrected?

The Van Der Waals equation of state can be corrected by introducing correction factors to account for the size of the gas molecules and the attractive forces between them. These corrections can be made by incorporating the compressibility factor and the reduced temperature and pressure into the equation.

## 4. What is the compressibility factor and how does it affect the Van Der Waals equation of state?

The compressibility factor, also known as the Z-factor, is a correction factor that takes into account the deviation of gases from ideal behavior. It is defined as the ratio of the actual volume of a gas to the volume predicted by the ideal gas law. As the compressibility factor deviates from 1, the Van Der Waals equation of state becomes less accurate.

## 5. What are some other equations of state that improve upon the Van Der Waals equation?

Several other equations of state have been developed to improve upon the Van Der Waals equation, such as the Redlich-Kwong equation, the Peng-Robinson equation, and the Soave-Redlich-Kwong equation. These equations incorporate additional parameters to better account for the non-ideal behavior of real gases.