619 
ode 
en 
en EN 
hence after logarithmic differentiation : _ 
2—p, dv 
a 
Bp (1—8) v 
so that the integral becomes: 
Vs E 
(148) (2— Dis =i ij | ( game GE 
Rebel ag pra. ME 
ee 8 (1—8) ate sai =p ; (BB) t log (B Be ) 
In this according to (a) 
hence 
and so finally : 
GRA g — RT logV + RT + RT log (a) | =o 
aa 4 ml Dr 
= | 7 ne en al — RT (6-- 8,), 
because pV = (1+) RT and pv, = Egt LB) RT. 
Hence: 
Gre, Zo = (tee) = C, — RT log v, + RT + RT log (1—3,), - (12) 
the known expression for § or u, when also v,, 5, refer to a gaseous 
state. 
If the state »,, 3, had been a liquid state, the correct expression 
would bave been found too, but in this case the integration would 
have given rise to great difficulties. 
3. Caleulation of (2°). Let us write this equation in the form: 
V Po 
Pts 
Orbo S ET SV.5 ic = pee ai ei = i, a>: (En) ) EY, 
v Oy) ay 
0s 
then for the molecular rn ie = i holds : 
Ny 
"RT 
(vo. — (u) va a —dv — (1 —1) Teed ea 
v = 
"9:0 
f 8 dv =n,.dv, die: 
because for perfect gases — == =. =~ Is no longer dependent 
v mi IV v 
1 1 1 
on the molecular values ZEN 
