# What is the molar form of the ideal gas law?

##### 1 Answer

The molar mass form of the ideal gas equation can be written as

where

P is the pressure the gas exerts on the walls of the container that confines it.

V is the volume of that container.

R is the ideal gas constant, 8.314 Joules per mole-Kelvin.

T is the temperature of the gas.

m is the mass of the gas.

M is the mass of the gas per mole.

The molar mass form of the ideal gas equation can be derived by substituting n (the amount of gas inside the container measured in moles) into the more common form of the ideal gas equation

where n = m/M. All other variables are the same as described above.

Divide both sides of the molar mass form of the ideal gas equation PV = (m/M) RT by V and we obtain

or

which is the other way to write the molar mass form of the ideal gas equation (as mentioned above), where ρ is the density of the gas, ρ = m/V. The symbol ρ might look like the letter "p" (as in Paul), but it is not. ρ is actually a greek letter pronounced "rho".