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Formula Definition of the Specific Gas Constant Molar mass   

Formula
Formula: Definition of the Specific Gas Constant
Isobaric, Isochoric, Isothermal and Adiabatic Process on the p-V Diagram

Specific gas constant

Unit
The specific gas constant indicates the ratio of the molar gas constant to the molar mass 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)\( 188.9 \, \frac{\mathrm J}{ \mathrm{kg}\, \mathrm{K} } \)

Molar mass

Unit
Molar mass [kg / mol] of a substance is the total mass \(m\) of the gas per amount of substance \(n\): \( M_{\text n} = m/n\).

GasMolar mass \(M_{\text n}\)
Helium (He)\( 4.003 \cdot 10^{-3} \, \frac{\mathrm{kg}}{ \mathrm{mol}} \)
Methane (CH4)\( 16.04 \cdot 10^{-3} \, \frac{\mathrm{kg}}{ \mathrm{mol}} \)
Nitrogen (N2)\( 28.01 \cdot 10^{-3} \, \frac{\mathrm{kg}}{ \mathrm{mol}} \)
Oxygen (O2)\( 32.00 \cdot 10^{-3} \, \frac{\mathrm{kg}}{ \mathrm{mol}} \)
Carbon dioxide (CO2)\( 44.01 \cdot 10^{-3} \, \frac{\mathrm{kg}}{ \mathrm{mol}} \)

Gas constant

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