SDN0013.05 – Properties of Liquid Nitrogen
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Molecular weight |
28.014 |
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Gas density |
4.415 g/l at 77 K |
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1.250 g/l at 273 K |
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Liquid density |
0.808 kg/l at 77 K |
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Vapor / liquid volume ratio |
646:1 (vapor at STP = 760 mm, 273 K) |
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Enthalpy of vaporization |
198.8 J/g (760 mm, 77.35 K) |
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= 160 kJ/l (760 mm, 77.35 K) |
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= 44.6 W-hr/l |
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Enthalpy of fusion |
25.3 J/g (93.9 mm, 63.15 K = triple point) |
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Heat capacity of liquid |
2.042 J/g-K (77.35 K) |
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Heat capacity of vapor |
1.341 J/g-K (77.35 K) |
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1.072 J/g-K (100 K) |
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1.046 J/g-K (200 K) |
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1.041 J/g-K (300 K) |
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238 J/g (77 – 300 K, approximate) |
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= 192 kJ/l (liquid) |
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= 53.4 W-hr/l |
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Energy to vaporize liquid and heat gas to 300 K |
437 J/g |
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= 352 kJ/l |
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= 98 W-h/l |
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Boiling Point |
77.35 K (760 mm) |
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76.67 K (700 mm; Tucson) |
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73.00 K (440 mm; Mauna Kea) |
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An empirical expression for the vapor pressure is: |
Log (P) = 6.49594 – 255.821/(T – 6.600) |
Plots of this relation follow. The critical temperature (Tc) = 126.2 K; the triple point (Tp) is marked on the plots with a dot at 63.15 K.
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If you have any questions or suggestions regarding this website, please contact Melissa Bowersock.
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National Optical Astronomy
Observatories, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726,
Phone: (520) 318-8000, Fax: (520) 318-8360