Gases - Specific Heat and Individual Gas Constants

Calculate specific heat at constant volume (cv), specific heat at constant pressure (cp), specific heat ratio (κ), and individual gas constants (R) for common ideal gases. Reference values at 68°F (20°C) and 14.7 psia (1 atm).

Calculator

Inputs

Select Gas

Specific Heat at Constant Pressure (cp) (kJ/kgK)

Specific Heat at Constant Volume (cv) (kJ/kgK)

Results

Specific Heat Ratio (κ = cp/cv)--

cp - cv (R gas constant)-- kJ/kgK

Gas or Vapor	Formula	cp (kJ/kgK)	cv (kJ/kgK)	κ (cp/cv)	R (kJ/kgK)	R (ft·lbf/(lbm·R))
Acetone	(CH3)2CO	1.47	1.32	1.11	0.15	—
Acetylene	C2H2	1.69	1.37	1.232	0.32	59.34
Air	—	1.007	0.718	1.4	0.289	53.34
Alcohol (ethanol)	C2H5OH	1.88	1.67	1.13	0.21	—
Alcohol (methanol)	CH3OH	1.93	1.53	1.26	0.4	—
Ammonia	NH3	2.16	1.66	1.31	0.5	96.5
Argon	Ar	0.52	0.312	1.667	0.208	—
Benzene	C6H6	1.09	0.99	1.1	0.1	—
Butane	C4H10	1.67	1.53	1.09	0.14	26.5
Carbon dioxide	CO2	0.8459	0.655	1.29	0.191	38.86
Carbon monoxide	CO	1.02	0.72	1.4	0.3	55.14
Chlorine	Cl2	0.48	0.36	1.33	0.12	—
Ethane	C2H6	1.75	1.48	1.18	0.27	51.5
Ether (diethyl)	(C2H5)2O	2.01	1.95	1.03	0.06	—
Ethylene	C2H4	1.53	1.23	1.24	0.3	55.08
Helium	He	5.251	3.12	1.68	2.08	386.3
Hydrogen	H2	14.32	10.16	1.41	4.16	765.9
Methane	CH4	2.22	1.7	1.3	0.52	96.4
Nitrogen	N2	1.041	0.743	1.4	0.298	54.99
Nitrous oxide	N2O	0.88	0.69	1.28	0.19	35.1
Oxygen	O2	0.9189	0.659	1.39	0.26	48.24
Propane	C3H8	1.67	1.48	1.13	0.19	35
Propene	C3H6	1.5	1.31	1.15	0.19	36.8
Steam (H2O)	H2O	1.97	1.5	1.31	0.47	—
Sulfur dioxide	SO2	0.64	0.51	1.25	0.13	24.1