Related Resources: thermodynamics

Properties Ideal Gases

Thermodynamics
Heat Transfer

Properties of Various Ideal Gases at 77 F°, 1 atm (English Units)

Gas
Chemical
Formula
Mol. Mass
(lbm/lbmol)
R
(ft-lbf/lbm R)
ρ × 103
(lbm/ft 3 )
Cρo
(Btu/lbm R)
Cv0
k
Cρo / Cv0
Steam
H2O
18.015
85.76
1.442
0.447
0.337
1.327
Acetylene
C2 H 2
26.038
59.34
65.55
0.406
0.330
1.231
Air
28.97
53.34
72.98
0.240
0.171
1.400
Ammonia
NH3
17.031
90.72
43.325
0.509
0.392
1.297
Argon
Ar
39.948
38.68
100.7
0.124
0.0745
1.667
Butane
C4 H10
58.124
26.58
150.3
0.410
0.376
1.091
Carbon dioxide
CO2
44.01
35.10
110.8
0.201
0.156
1.289
Carbon monoxide
CO
28.01
55.16
70.5
0.249
0.178
1.399
Ethane
C2 H6
30.07
51.38
76.29
0.422
0.356
1.186
Ethanol
C2H 5OH
46.069
33.54
117.6
0.341
0.298
1.145
Ethylene
C2 H4
28.054
55.07
71.04
0.370
0.299
1.237
Helium
He
4.003
386.0
10.08
1.240
0.744
1.667
Hydrogen
H 2
2.016
766.5
5.075
3.394
2.409
1.409
Methane
CH 4
16.043
96.35
40.52
0.538
0.415
1.299
Methanol
CH3OH
32.042
48.22
81.78
0.336
0.274
1.227
Neon
Ne
20.183
76.55
50.81
0.246
0.148
1.667
Nitric oxide
NO
30.006
51.50
75.54
0.237
0.171
1.387
Nitrogen
N 2
28.013
55.15
70.61
0.249
0.178
1.400
Nitrous oxide
N2O
44.013
35.10
110.8
0.210
0.165
1.274
n -octane
C8H18
114.23
13.53
5.74
0.409
0.391
1.044
Oxygen
O2
31.999
48.28
80.66
0.220
0.158
1.393
Propane
C3H8
44.094
35.04
112.9
0.401
0.356
1.126
R-12
CCl2F2
120.914
12.78
310.9
0.147
0.131
1.126
R-22
CHClF2
86.469
17.87
221.0
0.157
0.134
1.171
R-32
CF2 H2
52.024
29.70
132.6
0.196
0.158
1.242
R-125
CHF2 CF3
120.022
12.87
307.0
0.189
0.172
1.097
R-134a
CF3CH 2F
102.03
15.15
262.2
0.203
0.184
1.106
Sulfur dioxide
SO2
64.059
24.12
163.4
0.149
0.118
1.263
Sulfur trioxide
SO3
80.053
19.30
204.3
0.152
0.127
1.196

Or saturation pressure if it is less than 1 atm.