HEAT CAPACITY AND CALORIFIC INTENSITY CURVES 367
TABLE 10
P. 25, Les Sources de VEnergie Calorifique,
The formulas for the law for the heat capacity of gases at constant pressure
have been given by Mallard and Le Chatelier in terms of the absolute tem-
perature, and the total heat capacity from 0 absolute (273°) to a tem-
perature T = 273+t can be expressed by a parabolic formula of two terms:
,
lOO(T 10002'
in which a is a constant common to all gases, equal to 6.5 and b is a constant
variable with the different gases, the value of which is
For nitrogen, hydrogen, oxygen and carbon monoxide = 0.6;
For water vapor = 2. 9;
For carbon dioxide = 3. 7;
For methane = 6.0.
From this, the molecular heat capacity for a gram molecule or 22.32 liters
of a gas between two temperatures to = TQ 273 and t = T 273 may be
expressed by the formula:
n= T~TQ J*-TQ*
^ a 1000 + iooo2
By taking the values derived from this formula the specific heat for a
particular temperature may be obtained by the formula:
^LfV= a I 26 T
dT 1000 "'"lOOO2