Ideal gas law

Definition

The ideal gas law is a fundamental equation in physics and chemistry that relates the pressure, volume, temperature, and number of moles of an ideal gas. It is expressed as $PV=nRT$, where $P$ is pressure, $V$ is volume, $T$ is temperature (in Kelvin), $n$ is the number of moles, and $R$ is the universal gas constant.

5 Must Know Facts For Your Next Test

1. The ideal gas law combines Boyle's Law, Charles's Law, and Avogadro's Law into a single equation.
2. $R$, the universal gas constant, has a value of approximately 8.314 J/(mol·K).
3. Ideal gases are hypothetical gases that perfectly follow the ideal gas law without any deviations.
4. Real gases behave like ideal gases at high temperature and low pressure.
5. The ideal gas law assumes that intermolecular forces and molecular volumes are negligible.

Review Questions

• What are the variables in the ideal gas law equation?
• Under what conditions do real gases approximate the behavior of an ideal gas?
• How does increasing temperature affect the pressure of an ideal gas if volume remains constant?

Related terms

Boyle's Law: A principle stating that for a fixed amount of an ideal gas kept at a fixed temperature, pressure and volume are inversely proportional.

Charles's Law: A principle stating that for a fixed amount of an ideal gas at constant pressure, its volume is directly proportional to its absolute temperature.

Avogadro's Law: $n=kV$, where $n$ is the number of moles and $V$ is volume; states that equal volumes of all gases at the same temperature and pressure contain an equal number of molecules.