What is meant by the term "ideal gas"?

The term "ideal gas" refers to a hypothetical gas that perfectly conforms to the ideal gas laws, which include relationships between pressure, volume, temperature, and the number of moles of the gas. In this model, an ideal gas is characterized by the absence of intermolecular forces, meaning the particles do not attract or repel one another. Additionally, the molecules of an ideal gas occupy no volume themselves, allowing the gas to expand infinitely and fill any container uniformly.

By following these assumptions, an ideal gas demonstrates predictable behavior under various conditions of temperature and pressure, which allows for the derivation of equations such as the ideal gas law (PV = nRT). This concept is fundamental in thermodynamics and physical chemistry for understanding real gas behavior, as real gases approximate ideal gas behavior under conditions of high temperature and low pressure, where intermolecular forces and molecular volume become negligible.