# Formula Specific Gas Constant Mass    Boltzmann Constant

## Specific gas constant

Unit
The specific gas constant depends on the gas under consideration and, by definition, gives the ratio of the molar gas constant $$R$$ to the molar mass $$M_{\text n}$$ of a gas.

GasSpecific gas constant $$R_{\text s}$$
Helium (He)$$2077.1 \, \frac{\mathrm J}{ \mathrm{kg}\, \mathrm{K} }$$
Methane (CH4)$$518.4 \, \frac{\mathrm J}{ \mathrm{kg}\, \mathrm{K} }$$
Nitrogen (N2)$$296.8 \, \frac{\mathrm J}{ \mathrm{kg}\, \mathrm{K} }$$
Oxygen (O2)$$259.8 \, \frac{\mathrm J}{ \mathrm{kg}\, \mathrm{K} }$$
Carbon dioxide (CO2)$$188.9 \, \frac{\mathrm J}{ \mathrm{kg}\, \mathrm{K} }$$

## Mass

Unit
Mass of a gas particle (e.g. a He atom, when dealing with a helium gas).

## Boltzmann Constant

Unit
Boltzmann constant is a physical constant from many-particle physics and has the following exact value:$$k_{\text B} ~=~ 1.380 \, 649 ~\cdot~ 10^{-23} \, \frac{\mathrm{J}}{\mathrm{K}}$$