Ideal Gas Law Formula

The Formula

PV = nRT

When to use: If you squeeze a gas, heat it, or add more particles, the other gas properties must adjust in a predictable way.

Quick Example

Pumping air into a bicycle tire adds gas particles to nearly the same volume, so the pressure rises.

Notation

P is pressure, V is volume, n is amount in moles, R is the gas constant, and T is absolute temperature in kelvin.

What This Formula Means

The ideal gas law relates the pressure, volume, temperature, and amount of an ideal gas in one equation.

If you squeeze a gas, heat it, or add more particles, the other gas properties must adjust in a predictable way.

Formal View

For an ideal gas, PV = nRT, where R is the universal gas constant. The model assumes particles with negligible volume and no intermolecular forces.

Common Mistakes

  • Substituting Celsius instead of kelvin for temperature.
  • Using inconsistent pressure and volume units with the chosen gas constant.

Why This Formula Matters

The ideal gas law is a standard secondary-school model for gases and connects particle motion to measurable macroscopic quantities.

Frequently Asked Questions

What is the Ideal Gas Law formula?

The ideal gas law relates the pressure, volume, temperature, and amount of an ideal gas in one equation.

How do you use the Ideal Gas Law formula?

If you squeeze a gas, heat it, or add more particles, the other gas properties must adjust in a predictable way.

What do the symbols mean in the Ideal Gas Law formula?

P is pressure, V is volume, n is amount in moles, R is the gas constant, and T is absolute temperature in kelvin.

Why is the Ideal Gas Law formula important in Physics?

The ideal gas law is a standard secondary-school model for gases and connects particle motion to measurable macroscopic quantities.

What do students get wrong about Ideal Gas Law?

Temperature must be in kelvin, not degrees Celsius, when using PV = nRT.

What should I learn before the Ideal Gas Law formula?

Before studying the Ideal Gas Law formula, you should understand: pressure, temperature.