Note on the Gas Laws CHARLES A. STEVENSON Stokely Fooda,Inc.. Indiumpolis, I n d i u m
BY PURELY formal operations on the thermal equation of state it is possible to present in a direct manner the connection of necessity existing between the laws of Boyle and Charles. This equation of state may be written as f(P, V , T)
which in differential form is:
. . The following relations are matters of definition: coefficient of expansion,
a = -
This equation shows that a t a given pressure any one of the three coefficients a,0, a may be calculated when the other two are known. As an illustration of this relation between these coefficients we may derive Boyle's law directly from Charles' law as follows. According to Charles' law whence p
= -1 8.
coefficient of compression,
coefficient of tension,
Substituting the values of the partial derivatives given in the definitions in the differential equation of state, we have:
, +, dP
dV = 0 (constant T)
which is Boyle's law.