ABSTRACT
We also saw that at chemical equilibrium, Q becomes the equilibrium constant, K . Therefore, under equilibrium conditions Eqn [1] becomes:
0 = 6G° + RT ln K
from which ln K = < 6G RT
. . . [2]
That is, K = exp G
RT
<• –³
— ˜µ
6 . . . [3]
0 100 % Conversion to Products
Constant T and P
aA + bB A cC + dD
Fig. 1
Eqns [2] and [3] show that in order to calculate the equilibrium constant, all we need to know is the value of 6G° for the reaction, which is readily calculated from the standard thermodynamic data found in the appendices. The value of K given by Eqn [3] that is based on activities is known as the thermodynamic equilibrium constant.
