Page 127 - Chemical equilibria Volume 4

Hence, we are led to the expression of the old coordinates as a function of
the new ones: Molecular Chemical Equilibria 103
X + Y
x = [3.108a]
2

and:
Y − X
y =+ [3.108b]
1
2

This gives us the new equation for the curves:

()
()
−
−
X 2 ( 1 K 27 P ) − 2 2X = Y 2 ( 1 K 27 P ) − 2 [3.109]
If, in that equation, we change Y into –Y, X does not change, which
proves the symmetry in relation to the second diagonal.

Let us demonstrate the following property: in every transformation
(isothermal or otherwise), the space of points representative of those
intermediary states is a straight line with a slope of –k C/k H.

Indeed, when we take account of relations [3.99], [3.100] and [3.101], we
have:
{CO }
x = [3.110a]
k C

and:
{ }
H
y = 2 [3.110b]
k C
During the course of an elementary evolution of the extent of the
reaction, the coordinates of the figurative point will vary by dx and dy, such
that:
{
dCO }
d x = [3.111a]
k C