Critical points of the elements (data page)

Critical point

ref	Tc(K)	Tc(°C)	Pc(MPa)	Pc(other)	Vc(cm³/mol)	ρc(g/cm³)
1 H hydrogen
use	32.97	−240.18	1.293
CRC.a	32.97	−240.18	1.293		65
KAL	33.2		1.297		65.0
SMI		−239.9		13.2 kgf/cm²		0.0310
1 H hydrogen (equilibrium)
LNG		−240.17	1.294	12.77 atm	65.4	0.0308
1 H hydrogen (normal)
LNG		−239.91	1.297	12.8 atm	65.0	0.0310
1 H hydrogen-2
KAL	38.2		1.65		60
1 H hydrogen-2 (equilibrium)
LNG		−234.8	1.650	16.28 atm	60.4	0.0668
1 H hydrogen-2 (normal)
LNG		−234.7	1.665	16.43 atm	60.3	0.0669
2 He helium
use	5.19	−267.96	0.227
CRC.a	5.19	−267.96	0.227		57
KAL	5.19		0.227		57.2
SMI		−267.9		2.34 kgf/cm²		0.0693
2 He helium (equilibrium)
LNG		−267.96	0.2289	2.261 atm		0.06930
2 He helium-3
LNG		−269.85	0.1182	1.13 atm	72.5	0.0414
2 He helium-4
LNG		−267.96	0.227	2.24 atm	57.3	0.0698
3 Li lithium
use	(3223)	(2950)	(67)
CRC.b	(3223)	2950	(67)		(66)
7 N nitrogen
use	126.21	−146.94	3.39
CRC.a	126.21	−146.94	3.39		90
KAL	126.2		3.39		89.5
SMI		−147.1		34.7 kgf/cm²		0.3110
7 N nitrogen-14
LNG		−146.94	3.39	33.5 atm	89.5	0.313
7 N nitrogen-15
LNG		−146.8	3.39	33.5 atm	90.4	0.332
8 O oxygen
use	154.59	−118.56	5.043
CRC.a	154.59	−118.56	5.043		73
LNG		−118.56	5.043	49.77 atm	73.4	0.436
KAL	154.6		5.04		73.4
SMI		−118.8		51.4 kgf/cm²		0.430
9 F fluorine
use	144.13	−129.02	5.172
CRC.a	144.13	−129.02	5.172		66
LNG		−129.0	5.215	51.47 atm	66.2	0.574
KAL	144.3		5.22		66
10 Ne neon
use	44.4	−228.7	2.76
CRC.a	44.4	−228.7	2.76		42
LNG		−228.71	2.77	27.2 atm	41.7	0.4835
KAL	44.4		2.76		41.7
SMI		−228.7		26.8 kgf/cm²		0.484
11 Na sodium
use	(2573)	(2300)	(35)
CRC.b	(2573)	2300	(35)		(116)
15 P phosphorus
use	994	721
CRC.a	994	721
LNG		721
16 S sulfur
use	1314	1041	20.7
CRC.a	1314	1041	20.7
LNG		1041	11.7	116 atm
KAL	1314		20.7
SMI		1040
17 Cl chlorine
use	416.9	143.8	7.991
CRC.a	416.9	143.8	7.991		123
LNG		143.8	7.71	76.1 atm	124	0.573
KAL	416.9		7.98		124
SMI		144.0		78.7 kgf/cm²		0.573
18 Ar argon
use	150.87	−122.28	4.898
CRC.a	150.87	−122.28	4.898		75
LNG		−122.3	4.87	48.1 atm	74.6	0.536
KAL	150.9		4.90		74.6
SMI		−122		49.7 kgf/cm²		0.531
19 K potassium
use	(2223)	(1950)	(16)
CRC.b	(2223)	1950	(16)		(209)
33 As arsenic
use	1673	1400
CRC.a	1673	1400			35
LNG		1400
34 Se selenium
use	1766	1493	27.2
CRC.a	1766	1493	27.2
LNG		1493
35 Br bromine
use	588	315	10.34
CRC.a	588	315	10.34		127
LNG		315	10.3	102 atm	135	1.184
KAL	588		10.3		127
SMI		302				1.18
36 Kr krypton
use	209.41	−63.74	5.50
CRC.a	209.41	−63.74	5.50		91
LNG		−63.75	5.50	54.3 atm	91.2	0.9085
KAL	209.4		5.50		91.2
37 Rb rubidium
use	(2093)	(1820)	(16)
CRC.b	(2093)	1820	(16)		(247)
LNG		1832			250	0.34
53 I iodine
use	819	546	11.7
CRC.a	819	546			155
LNG		546	11.7	115 atm	155	0.164
KAL	819				155
SMI		553
54 Xe xenon
use	289.77	16.62	5.841
CRC.c	289.77	16.62	5.841		118
LNG		16.583	5.84	57.64 atm	118	1.105
KAL	289.7		5.84		118
SMI		16.6		60.2 kgf/cm²		1.155
55 Cs caesium
use	1938	1665	9.4
CRC.d	1938	1665	9.4		341
LNG		1806			300	0.44
80 Hg mercury
use	1750	1477	172.00
CRC.a	1750	1477	172.00		43
LNG		1477	160.8	1587 atm
KAL	1750		172		42.7
SMI		1460±20		1640±50 kgf/cm²		0.5
86 Rn radon
use	377	104	6.28
CRC.a	377	104	6.28
LNG		104	6.28	62 atm	139	1.6
KAL	377		6.3
SMI		104		64.1 kgf/cm²

References

CRC.a-d

David R. Lide (ed), CRC Handbook of Chemistry and Physics, 85th Edition, online version. CRC Press. Boca Raton, Florida, 2003; Section 6, Fluid Properties; Critical Constants. Also agrees with Celsius values from Section 4: Properties of the Elements and Inorganic Compounds, Melting, Boiling, Triple, and Critical Point Temperatures of the Elements

Estimated accuracy for Tc and Pc is indicated by the number of digits. Above 750 K Tc values may be in error by 10 K or more. Vc values are not assumed accurate more than to a few percent. Parentheses indicate extrapolated values. From these sources:

• (a) D. Ambrose, Vapor-Liquid Constants of Fluids, in R.M. Stevenson, S. Malanowski, Handbook of the Thermodynamics of Organic Compounds, Elsevier, New York, (1987).
• (b) I.G. Dillon, P.A. Nelson, B.S. Swanson, J. Chem. Phys. 44, 4229, (1966).
• (c) O. Sifner, J. Klomfar, J. Phys. Chem. Ref. Data 23, 63, (1994).
• (d) N.B. Vargaftik, Int. J. Thermophys. 11, 467, (1990).

LNG

J.A. Dean (ed), Lange's Handbook of Chemistry (15th Edition), McGraw-Hill, 1999; Section 6; Table 6.5 Critical Properties

KAL

National Physical Laboratory, Kaye and Laby Tables of Physical and Chemical Constants; D. Ambrose, M.B. Ewing, M.L. McGlashan, Critical constants and second virial coefficients of gases (retrieved Dec 2005)

SMI

W.E. Forsythe (ed.), Smithsonian Physical Tables 9th ed., online version (1954; Knovel 2003). Table 259, Critical Temperatures, Pressures, and Densities of Gases

See also