**The ideal gas law is an equation that combines Avogadro’s law with the combined gas law.** The ideal gas law holds true for ideal gases. Remember that an ideal gas is unlike a real gas because of the following assumptions.

- The particles of an ideal gas are considered to be small, hard spheres with no mass and no volume.
- The particles of an ideal gas are not attracted to each other.
- The particles of an ideal gas are moving very rapidly and randomly.
- The particles of an ideal gas are colliding with each other in perfectly elastic collisions.

The ideal gas law is shown by the following equation.

where,

**P** is the **pressure** of the gas (in atm or kPa)

**V** is the **volume** of the gas (in L)

**n** is the **number of moles** of gas

**R** is the **ideal gas constant** ( 0.08206 L·atm·mol^{−1}·K^{−1 } or 8.3144 L·kPa·mol^{−1}·K^{−1})

**T** is the **temperature** of the gas (in K)