Formula Specific Gas Constant Isobaric specific heat capacity Isochoric specific heat capacity
$$R_{\text s} ~=~ c_{\Pi} ~-~ c_{\text V}$$ $$R_{\text s} ~=~ c_{\Pi} ~-~ c_{\text V}$$ $$c_{\Pi} ~=~ R_{\text s} ~+~ c_{\text V}$$ $$c_{\text V} ~=~ c_{\Pi} ~-~ R_{\text s}$$
Specific gas constant
$$ R_{\text s} $$ Unit $$ \frac{\mathrm{J}}{\mathrm{kg} \, \mathrm{K}} = \frac{\mathrm{m}^2}{\mathrm{s}^2 \, \mathrm{K}} $$ 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.
| Gas | Specific 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) | \( 188.9 \, \frac{\mathrm J}{ \mathrm{kg}\, \mathrm{K} } \) |
Isobaric specific heat capacity
$$ c_{\Pi} $$ Unit $$ \frac{\mathrm{J}}{\mathrm{kg} \, \mathrm{K}} = \frac{\mathrm{m}^2}{\mathrm{s}^2 \, \mathrm{K}} $$ Specific heat capacity at constant pressure \(\mathit{\Pi}\) indicates how much energy must be added to a kilogram of substance to heat it up by 1 Kelvin.
Isochoric specific heat capacity
$$ c_{\text V} $$ Unit $$ \frac{\mathrm{J}}{\mathrm{kg} \, \mathrm{K}} = \frac{\mathrm{m}^2}{\mathrm{s}^2 \, \mathrm{K}} $$ Specific heat capacity at constant volume \(V\).