# Formula Ideal Gas Law Pressure    Volume    Temperature    Amount of substance    Gas constant

## Pressure

Unit
This pressure is present in a confined system containing an ideal gas. According to the ideal gas law, the pressure increases when the temperature $$T$$ of the gas increases or the volume $$V$$ in which the gas is confined decreases.

## Volume

Unit
The volume of a closed system containing an ideal gas.

## Temperature

Unit
It is the absolute temperature (in Kelvin) of the gas in a closed system.

## Amount of substance

Unit
The amount of substance indirectly indicates the number of gas particles. It is related to the particle number $$N$$ by the Avogardo constant $$N_{\text A}$$: $$n = \frac{N}{N_{\text A}}$$.

## Gas constant

Unit
Molar gas constant (also called universal gas constant) is a physical constant from thermodynamics and has the following exact value:$$R ~=~ 8.314 \, 462 \, 618 \, 153 \, 24 \, \frac{\mathrm J}{\mathrm{mol} \, \mathrm{K}}$$