Irodov – Problems in General Physics

(Joyce) #1

15. Gas Constants


(under standard conditions)

Gas

Relative
molecular
mass

Cp
V

Heat con-
ductivity
mW

Viscosity
11, ftPa•8

Molecular
dia-
meter
d, nm

Van der Weals
constants

a, atm• 1^2 b,
mol

m•K
molt

He 4 1.67 141.5 18.9 0.20 -- --
Ar 40 1.67 16.2 22.1 0.35 1.30 0.032
H2 2 1.41 188.4 8.4 0.27 0.24 0.027
Na 28 1.40 24.3 16.7 0.37 1.35 0.039
0 2 32 1.40 24.4 19.2 0.35 1.35 0.032
CO 2 44 1.30 23.2 14.0 0.40 3.62 0.043

H (^2) O 18 1.32 15.8 9.0 0.30 5.47 0.030
Air 29 1.40 24.1 17.2 0.35 -- --
No e. This table quotes the mean values of molecular diameters.
When performing more accurate calculations, it should be remembered
that the values of d obtained from the coefficients of viscos ty, heat
conductivity, and diffusion, as well as the Van der Waals constant b,
differ perceptibly from one another.


16. Some Parameters of Liquids and Solids


Substance

Specific heat
capacity *
c,

Specific heat of
vaporization **
q, J/g

Specific heat of
melting
q, J/g

Surface
tension *
g•K mN/m

Water 4.18^2250 73
Glycerin 2.42^66
Mercury 0.14^284 490
Alcohol 2.42^853 22
Aluminum 0.90^321
Iron 0.46^270
Ice 2.09^333
Copper 0.39^175
Silver 0.23^88
Lead 0.13^25

* Under standard conditions.
** Under standard atmospheric pressure.
n. n
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