specific heat in a constant pressure process

Gases - Specific Heats and Individual Gas Constants

Specific heat at constant volume, specific heat at constant pressure, specific heat ratio and individual gas constant - R - common gases as argon, air, ether, nitrogen and many more ..

The specific heats at constant pressure and constant volume processes, and the ratio of specific heats and individual gas constants - R - for some common used "ideal gases", are in the table below (approximate values at 68^oF (20^oC) and 14.7 psia (1 atm)):

Gas or Vapor	Formula	Specific Heat				Specific Heat Ratio	Individual Gas constant - R -
		cp (kJ/(kg K))	cv (kJ/(kg K))	cp (Btu/(lbmoF))	cv (Btu/(lbmoF))	κ = cp / cv	cp - cv (kJ/(kg K))	cp - cv (ft lbf/(lbmoR))
Acetone		1.47	1.32	0.35	0.32	1.11	0.15
Acetylene	C2H2	1.69	1.37	0.35	0.27	1.232	0.319	59.34
Air		1.01	0.718	0.24	0.17	1.40	0.287	53.34
Alcohol	C2H5OH	1.88	1.67	0.45	0.4	1.13	0.22
Alcohol	CH3OH	1.93	1.53	0.46	0.37	1.26	0.39
Ammonia	NH3	2.19	1.66	0.52	0.4	1.31	0.53	96.5
Argon	Ar	0.520	0.312	0.12	0.07	1.667	0.208
Benzene	C6H6	1.09	0.99	0.26	0.24	1.12	0.1
Blast furnace gas		1.03	0.73	0.25	0.17	1.41	0.3	55.05
Bromine		0.25	0.2	0.06	0.05	1.28	0.05
Butatiene						1.12
Butane	C4H10	1.67	1.53	0.395	0.356	1.094	0.143	26.5
Carbon dioxide	CO2	0.844	0.655	0.21	0.16	1.289	0.189	38.86
Carbon monoxide	CO	1.02	0.72	0.24	0.17	1.40	0.297	55.14
Carbon disulphide		0.67	0.55	0.16	0.13	1.21	0.12
Chlorine	Cl2	0.48	0.36	0.12	0.09	1.34	0.12
Chloroform		0.63	0.55	0.15	0.13	1.15	0.08
Coal gas		2.14	1.59
Combustion products		1		0.24
Ethane	C2H6	1.75	1.48	0.39	0.32	1.187	0.276	51.5
Ether		2.01	1.95	0.48	0.47	1.03	0.06
Ethylene	C2H4	1.53	1.23	0.4	0.33	1.240	0.296	55.08
Monochlorodifluoromethane, R-22						1.18
Helium	He	5.19	3.12	1.25	0.75	1.667	2.08	386.3
Hexane						1.06
Hydrochloric acid		0.795	0.567
Hydrogen	H2	14.32	10.16	3.42	2.43	1.405	4.12	765.9
Hydrogen Chloride	HCl	0.8	0.57	0.191	0.135	1.41	0.23	42.4
Hydrogen Sulfide	H2S			0.243	0.187	1.32		45.2
Hydroxyl	OH	1.76	1.27			1.384	0.489
Krypton		0.25	0.151
Methane	CH4	2.22	1.70	0.59	0.45	1.304	0.518	96.4
Methyl Chloride	CH3Cl			0.240	0.200	1.20		30.6
Natural Gas		2.34	1.85	0.56	0.44	1.27	0.5	79.1
Neon		1.03	0.618			1.667	0.412
Nitric Oxide	NO	0.995	0.718	0.23	0.17	1.386	0.277
Nitrogen	N2	1.04	0.743	0.25	0.18	1.400	0.297	54.99
Nitrogen tetroxide		4.69	4.6	1.12	1.1	1.02	0.09
Nitrous oxide	N2O	0.88	0.69	0.21	0.17	1.27	0.18	35.1
Oxygen	O2	0.919	0.659	0.22	0.16	1.395	0.260	48.24
Pentane						1.07
Propane	C3H8	1.67	1.48	0.39	0.34	1.13	0.189	35.0
Propene (propylene)	C3H6	1.5	1.31	0.36	0.31	1.15	0.18	36.8
Water Vapor Steam 1 psia. 120 – 600 oF		1.93	1.46	0.46	0.35	1.32	0.462
Steam 14.7 psia. 220 – 600 oF		1.97	1.5	0.47	0.36	1.31	0.46
Steam 150 psia. 360 – 600 oF		2.26	1.76	0.54	0.42	1.28	0.5
Sulfur dioxide (Sulphur dioxide)	SO2	0.64	0.51	0.15	0.12	1.29	0.13	24.1
Xenon		0.16	0.097

• κ = c_p / c_v - the specific heat capacity ratio
• c_p = specific heat in a constant pressure process
• c_v = specific heat in a constant volume process
• R- Individual Gas constant