Critical Constants

Substance Formula Molecular Mass Temperature (K) Temperature (R) Pressure (MPa) Pressure (lbf/in.2) Volume (m3/kg) Volume (ft3/lbm)
Ammonia NH3 17.031 405.50 729.90 11.350 1646.0 0.004260 0.0682
Argon Ar 39.948 150.80 271.40 4.870 706.0 0.001880 0.0300
Bromine Br2 159.808 588.00 1058.40 10.300 1494.0 0.000796 0.0127
Carbon dioxide CO2 44.010 304.10 547.40 7.380 1070.0 0.002120 0.0342
Carbon monoxide CO 28.010 132.90 239.20 3.500 508.0 0.003330 0.0533
Chlorine Cl2 70.906 416.90 750.40 7.980 1157.0 0.001750 0.0280
Fluorine F2 37.997 144.30 259.70 5.220 757.0 0.001740 0.0279
Helium He 4.003 5.19 9.34 0.227 32.9 0.014300 0.2300
Hydrogen (normal) H2 2.016 33.20 59.76 1.300 188.6 0.032300 0.5170
Krypton Kr 83.800 209.40 376.90 5.500 798.0 0.001090 0.0174
Neon Ne 20.183 44.40 79.92 2.760 400.0 0.002060 0.0330
Nitric oxide NO 30.006 180.00 324.00 6.480 940.0 0.001920 0.0308
Nitrogen N2 28.013 126.20 227.20 3.390 492.0 0.003200 0.0514
Nitrogen dioxide NO2 46.006 431.00 775.80 10.100 1465.0 0.003650 0.0584
Nitrous oxide N2O 44.013 309.60 557.30 7.240 1050.0 0.002210 0.0354
Oxygen O2 31.999 154.60 278.30 5.040 731.0 0.002290 0.0367
Sulfur dioxide SO2 64.063 430.80 775.40 7.880 1143.0 0.001910 0.0306
Water H2O 18.015 647.30 1165.10 22.120 3208.0 0.003170 0.0508
Xenon Xe 131.300 289.70 521.50 5.840 847.0 0.000902 0.0144
Acetylene C2H2 26.038 308.30 554.90 6.140 891.0 0.004330 0.0693
Benzene C6H6 78.114 562.20 1012.00 4.890 709.0 0.003320 0.0531
n-Butane C4H10 58.124 425.20 765.40 3.800 551.0 0.004390 0.0703
Chlorodifluoroethane (142b) CH3CClF2 100.495 410.30 738.50 4.250 616.0 0.002300 0.0368
Chlorodifluoromethane (22) CHClF2 86.469 369.30 664.70 4.970 721.0 0.001910 0.0307
Dichlorodifluoroethane (141) CH3CCl2F 116.950 481.50 866.70 4.540 658.0 0.002150 0.0345
Dichlorotrifluoroethane (123) CHCl2CF3 152.930 456.90 822.40 3.660 532.0 0.001820 0.0291
Difluoroethane (152a) CHF2CH3 66.050 386.40 695.50 4.520 656.0 0.002720 0.0435
Difluoromethane (32) CH2F2 52.024 351.30 632.30 5.780 838.0 0.002360 0.0378
Ethane C2H6 30.070 305.40 549.70 4.880 708.0 0.004930 0.0790
Ethyl alcohol C2H5OH 46.069 513.90 925.00 6.140 891.0 0.003630 0.0581
Ethylene C2H4 28.054 282.40 508.30 5.040 731.0 0.004650 0.0744
n-Heptane C7H16 100.205 540.30 972.50 2.740 397.0 0.004310 0.0691
n-Hexane C6H14 86.178 507.50 913.50 3.010 437.0 0.004290 0.0688
Methane CH4 16.043 190.40 342.70 4.600 667.0 0.006150 0.0990
Methyl alcohol CH3OH 32.042 512.60 922.70 8.090 1173.0 0.003680 0.0590
n-Octane C8H18 114.232 568.80 1023.80 2.490 361.0 0.004310 0.0690
Pentafluoroethane (125) CHF2CF3 120.022 339.20 610.60 3.620 525.0 0.001760 0.0282
n-Pentane C5H12 72.151 469.70 845.50 3.370 489.0 0.004210 0.0675
Propane C3H8 44.094 369.80 665.60 4.250 616.0 0.004540 0.0964
Propene C3H6 42.081 364.90 656.80 4.600 667.0 0.004300 0.0689
Tetrafluoroethane (134a) CF3CH2F 102.030 374.20 673.60 4.060 589.0 0.001970 0.0311