Applied Mathematics/The State Equation

Ideal gas law
As an experimental rule, about gas, the equation below is found.
 * $$PV=nRT$$...(1)

where
 * $$\ p$$ = Pressure (absolute)
 * $$\ V$$ = Volume
 * $$\ n$$ = Number of moles of a substance
 * $$\ T$$ = Absolute temperature
 * $$\ R$$ = Gas constant
 * $$R\simeq8.31J(Kmol)^{-1}$$

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:
 * $$R=0.082LatmK^{-1}mol^{-1}$$

But, in university, the gas constant below is often used:
 * $$R=8.31 JK^{-1}mol^{-1}$$