Ideal gas

Definition

An ideal gas is a hypothetical gas that follows the ideal gas law, where its particles do not interact except through elastic collisions and occupy no volume. This model simplifies the study of gases by assuming perfectly random motion and no intermolecular forces.

5 Must Know Facts For Your Next Test

1. The ideal gas law is given by $PV = nRT$ where $P$ is pressure, $V$ is volume, $n$ is the number of moles, $R$ is the universal gas constant, and $T$ is temperature in Kelvin.
2. Ideal gases assume no intermolecular forces and that the particles themselves have no volume.
3. The internal energy of an ideal gas depends only on its temperature and not on its pressure or volume.
4. Ideal gases follow the principles of kinetic theory, which includes assumptions like elastic collisions and random motion of molecules.
5. Real gases approximate ideal behavior at high temperatures and low pressures.

Review Questions

• What assumptions are made about particles in an ideal gas?
• Write down the ideal gas law equation and explain each term briefly.
• Under what conditions do real gases behave most like an ideal gas?

Related terms

Kinetic Theory of Gases:

A theory that describes a gas as a large number of small particles (atoms or molecules), all of which are in constant random motion.

Boyle's Law:

$PV = k$, stating that for a fixed amount of an ideal gas kept at a fixed temperature, pressure and volume are inversely proportional.

Charles's Law:

$V \propto T$, indicating that for a fixed amount of an ideal gas at constant pressure, volume is directly proportional to its absolute temperature.