Specific heat capacity of gas at constant pressure

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

Symbol
$c_{p,gas}$
Unit
J/(kg.K)
Formulae
${10}^3\left(1.004571427+2.05063275{\cdot}{10}^{-3} \theta_{gas}-1.631537093{\cdot}{10}^{-4} {\theta_{gas}}^2+6.2123003{\cdot}{10}^{-6} {\theta_{gas}}^3-8.830478888{\cdot}{10}^{-8} {\theta_{gas}}^4+5.071307038{\cdot}{10}^{-10} {\theta_{gas}}^5\right)$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)
$1030.5-0.19975T_{gas}+3.9734{\cdot}{10}^{-4} {T_{gas}}^2$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
Related
$R_{gas}$
$\theta_{abs}$
$\theta_{gas}$
Used in
Choices
GasFormula0°C15°C25°C50°C75°C100°C
Air78%N2+21%O2+minor1005.91006.21006.51008.51010.21012.9
N2N21041.41041.41041.41041.61042.21043.3
SF6SF6627.83652.96668.99706.12739.88770.06
CO2CO2826.84841.24850.85874.53897.43919.36
COCO1042.01042.01042.11042.81044.01045.8
O2O2916.72918.22919.62923.64928.66934.55
H2H214197.614267.614306.3143791442714458
NH3NH32179.52166.22164.52176.42203.02238.6
SO2SO2669.21658.98656.2657.12663.98673.57
HeHe5193.15192.95192.95193.05193.05193.0
ArAr521.85521.65521.55521.34521.18521.05
KrKr249.5249.31249.2248.99248.83248.71
XeXe160.67160.29160.09159.7159.43159.23
NeNe1030.41030.31030.31030.31030.31030.2