What does the equation PV = nRT express?

The equation PV = nRT expresses the Ideal Gas Law, which describes the behavior of an ideal gas. In this formula:

• P represents the pressure of the gas,

• V is the volume,

• n is the number of moles of the gas,

• R is the ideal gas constant, and

• T is the absolute temperature in Kelvin.

The Ideal Gas Law combines several individual gas laws, including Boyle's Law and Charles' Law, and gives a comprehensive understanding of how a gas behaves under various conditions. It allows for the calculation of one of the variables when the others are known and assumes that the gas behaves ideally, meaning that there are no intermolecular forces acting between the gas molecules and that the volume of the gas particles themselves is negligible compared to the volume of the container.

Boyle's Law and Charles' Law focus on specific relationships involving pressure and volume, and temperature and volume, respectively, but do not encompass the full range of relationships described by the Ideal Gas Law. Densitometry is unrelated to the behavior of gases but rather concerns the measurement of density.

This equation's significance in various scientific and engineering applications, particularly in thermodynamics, makes it a cornerstone of understanding gas behavior in both theoretical and practical scenarios.