PHYSICAL CHEMISTRY IN BRIEF

CHAP. 8: CHEMICAL EQUILIBRIUM [CONTENTS] 235

Obr.8.2:Dependence of ∆rGon the activity of carbon oxide

or

∑k

i=1

νiμi= 0 [eq]. (8.13)

S Symbols:[eq] denotes the condition applying at equilibrium.

Example

What relation has to apply at equilibrium between the chemical potentials of substances A and

B bound by the reaction

0 = B− 2 A.

Solution

From (8.13) we obtain

μB= 2μA.

From (8.10) at equilibrium we obtain

∆rGst=−RTln

∏k

i=1

aνi,ieq, (8.14)

whereai,eqdenotes the activities of reacting substances in equilibrium.