# ME12: THERMOPHYSICAL PROPERTIES OF AIR

Boiling temperature (at 1 bar):  78.8 K = -194.4 °C = -317.8 °F

Bulk modulus elasticity:  1.01325 x 105 Pa or N/m2

Condensation temperature (at 1 bar):   81.8 K = -191.4 °C = -312.5 °F

Critical temperature:  132.63 K = -140.52 °C = -220.94 °F

Critical pressure: 37.363 atm = 37.858 bar = 3.7858 MPa (MN/m2) = 549.08 psi (=lbf/in2)

Critical density: 10.448 mol/dm3 = 302.6 kg/m3 = 0.5871 slug/ft3 = 18.89 lbm/ft3

Density  (at 0°C and 1 bar):   1.276 kg/m3 = 0.00248 slug/ft3 = 0.0797 lb/ft3

Density (at 60°F and 1 atm): 1.208 kg/m3 = 0.00234 slug/ft3 = 0.0754 lb/ft3

Enthalpy (heat) of air at 0°C  and 1 bar:  11.57  kJ/mol = 399.4  kJ/kg = 171.7 Btu(IT)/lb

Entropy of air at 0°C  and 1 bar:  0.1100 kJ/mol K = 3.796 kJ/kg K = 0.9067 Btu(IT)/lb °F

Liquid density at boiling point and 1 bar:   875.50 kg/m3 = 54.656 lb/ft3

Molar mass:   28.9647 g/mol

Specific heat capacity (Cp) air at 0°C and 1 bar: 1.006 kJ/kgK = 0.24028 Btu(IT)/(lbm °F) or kcal/(kg K)

Specific heat capacity (Cv) air at 0°C and 1 bar: 0.7171 kJ/kgK = 0.17128 Btu(IT)/(lbm °F) or kcal/(kg K)

Thermal conductivity at 0°C and 1 bar:   24.35 mW/(m K) = 0.02094 kcal(IT)/(h m K) = 0.01407 Btu(IT)/(h ft °F)

Thermal expansion coefficient at 0°C and 1 bar: 0.00369 1/K  = 0.00205 1/°F

Triple point pressure:   0.05196 atm = 0.05265 bar = 5265 Pa = 0.7636 psi (=lbf/in2)

Triple point temperature:  59.75 K = -213.40 °C = -352.12 °F

Viscosity, dynamic, at 0°C and 1 bar:   17.22 μPa s = 0.01722 cP = 0.3596×10-6(lbf s)/ft2  = 11.57×10-6 lbm/(ft s)

Viscosity, kinematic, at 0°C and 1 bar: 0.00001349 m2/s = 13.49 cSt = 0.0001452 ft2/s