Differences between Real and Ideal Gases

Oct 13, 2025 by thesweetdesigns.com 45 views

Introduction

Gases are an essential component of our daily lives, and understanding their behavior is crucial in various fields, including chemistry, physics, and engineering. In this article, we will delve into the concept of gases and explore the differences between "real" gases and "ideal" gases. Understanding these differences is vital in accurately predicting and modeling gas behavior.

What are Ideal Gases?

Ideal gases are hypothetical gases that obey the ideal gas law, which is a mathematical equation that describes the behavior of gases under various conditions. The ideal gas law is given by the equation:

PV = nRT

where P is the pressure of the gas, V is the volume of the gas, n is the number of moles of the gas, R is the gas constant, and T is the temperature of the gas.

Ideal gases are characterized by the following properties:

No intermolecular forces: Ideal gases do not have any intermolecular forces, which means that the molecules do not interact with each other.
No molecular size: Ideal gases are assumed to have no molecular size, which means that the molecules are point particles.
Constant volume: Ideal gases are assumed to have a constant volume, which means that the volume of the gas does not change with temperature or pressure.

What are Real Gases?

Real gases, on the other hand, are actual gases that do not obey the ideal gas law. Real gases exhibit non-ideal behavior due to the presence of intermolecular forces and molecular size. The properties of real gases are:

Intermolecular forces: Real gases have intermolecular forces, which affect the behavior of the gas.
Molecular size: Real gases have molecular size, which affects the behavior of the gas.
Variable volume: Real gases have a variable volume, which means that the volume of the gas changes with temperature or pressure.

Differences between Real and Ideal Gases

Now that we have discussed the properties of ideal and real gases, let's explore the differences between them.

1. Intermolecular Forces

Ideal gases do not have any intermolecular forces, while real gases have intermolecular forces that affect their behavior. Intermolecular forces are responsible for the non-ideal behavior of real gases.

2. Molecular Size

Ideal gases are assumed to have no molecular size, while real gases have molecular size that affects their behavior. Molecular size is responsible for the non-ideal behavior of real gases.

3. Variable Volume

Ideal gases are assumed to have a constant volume, while real gases have a variable volume that changes with temperature or pressure. Variable volume is responsible for the non-ideal behavior of real gases.

Conclusion

In conclusion, ideal gases are hypothetical gases that obey the ideal gas law, while real gases are actual gases that exhibit non-ideal behavior due to the presence of intermolecular forces and molecular size. Understanding the differences between real and ideal gases is crucial in accurately predicting and modeling gas behavior.

References

Gases and Their Properties by John W. Tester and Michael M. Modell
Thermodynamics: An Introduction to the Physical Theories of Equilibrium Thermostatics and Irreversible Thermodynamics by C. J. Adkins
Physical Chemistry: A Molecular Approach by Peter Atkins and Julio de Paula