The specific heat capacity of a material on a per mass basis is $c=\delta{C}/\delta{m}$. with $C$ being the heat capacity of a body made of the material and $m$ being the mass of the body.
For gases, there is need to distinguish between different boundary conditions for the processes under consideration. Typical processes for which a heat capacity may be defined include isobaric (constant pressure, d$P$ = 0) or isochoric (constant volume, d$V$ = 0) processes.
The sources are:
Note: 1 J = 1 W.s
${10}^3\left(1.004571427+2.05063275{\cdot}{10}^{-3} \theta_{gas}-1.631537093{\cdot}{10}^{-4} {\theta_{gas}}^2+6.2123003{\cdot}{10}^{-6} {\theta_{gas}}^3-8.830478888{\cdot}{10}^{-8} {\theta_{gas}}^4+5.071307038{\cdot}{10}^{-10} {\theta_{gas}}^5\right)$ | humid air @ 1 atm (Tsilingiris2007) |
$1.9327{\cdot}{10}^{-10} {T_{gas}}^4-7.9999{\cdot}{10}^{-7} {T_{gas}}^3+1.1407{\cdot}{10}^{-3} {T_{gas}}^2-4.489{\cdot}{10}^{-1} T_{gas}+1.0575{\cdot}{10}^3$ | air @ 1 bar (Dumas&Trancossi2009) |
$1030.5-0.19975T_{gas}+3.9734{\cdot}{10}^{-4} {T_{gas}}^2$ | dry air @ 1 bar (UW/MHTL 8406, 1984) |
${10}^3\left(0.103409{\cdot}{10}^1-0.284887{\cdot}{10}^{-3} T_{gas}+0.7816818{\cdot}{10}^{-6} {T_{gas}}^2-0.4970786{\cdot}{10}^{-9} {T_{gas}}^3+0.1077024{\cdot}{10}^{-12} {T_{gas}}^4\right)$ | dry air @ at 1 atm (Irvine&Liley1984) |
$1037+0.101\theta_{gas}$ | N2 (Vermeer1983) |
$630+1.87\theta_{gas}-4.33{\cdot}{10}^{-3} {\theta_{gas}}^2$ | SF6 (Vermeer1983) |
$539.52+1.0149\left(\theta_{gas}+\theta_{abs}\right)$ | CO2 (linear interpolation) |
$868.62+1.1029\left(\theta_{gas}+\theta_{abs}\right)$ | O2 (linear interpolation) |
$\frac{3}{2} R_{gas}$ | Monoatomic ideal gas |
$\frac{7}{2} R_{gas}$ | Diatomic molecule gas |
$4R_{gas}$ | Polyatomic molecule gas |
Gas | Formula | 0°C | 15°C | 25°C | 50°C | 75°C | 100°C |
---|---|---|---|---|---|---|---|
Air | 78%N2+21%O2+minor | 1005.9 | 1006.2 | 1006.5 | 1008.5 | 1010.2 | 1012.9 |
N2 | N2 | 1041.4 | 1041.4 | 1041.4 | 1041.6 | 1042.2 | 1043.3 |
SF6 | SF6 | 627.83 | 652.96 | 668.99 | 706.12 | 739.88 | 770.06 |
CO2 | CO2 | 826.84 | 841.24 | 850.85 | 874.53 | 897.43 | 919.36 |
CO | CO | 1042.0 | 1042.0 | 1042.1 | 1042.8 | 1044.0 | 1045.8 |
O2 | O2 | 916.72 | 918.22 | 919.62 | 923.64 | 928.66 | 934.55 |
H2 | H2 | 14197.6 | 14267.6 | 14306.3 | 14379 | 14427 | 14458 |
NH3 | NH3 | 2179.5 | 2166.2 | 2164.5 | 2176.4 | 2203.0 | 2238.6 |
SO2 | SO2 | 669.21 | 658.98 | 656.2 | 657.12 | 663.98 | 673.57 |
He | He | 5193.1 | 5192.9 | 5192.9 | 5193.0 | 5193.0 | 5193.0 |
Ar | Ar | 521.85 | 521.65 | 521.55 | 521.34 | 521.18 | 521.05 |
Kr | Kr | 249.5 | 249.31 | 249.2 | 248.99 | 248.83 | 248.71 |
Xe | Xe | 160.67 | 160.29 | 160.09 | 159.7 | 159.43 | 159.23 |
Ne | Ne | 1030.4 | 1030.3 | 1030.3 | 1030.3 | 1030.3 | 1030.2 |