# Applied Mathematics/The State Equation

## Ideal gas law

editAs an experimental rule, about gas, the equation below is found.

- ...(1)

where

- = Pressure (absolute)
- = Volume
- = Number of moles of a substance
- = Absolute temperature
- = Gas constant

The gas which strictly follows the law (1) is called **ideal gas**. (1) is called **ideal gas law**. Ideal gas law is the state equation of gas.
In high school, the ideal gas constant below might be used:

But, in university, the gas constant below is often used: