Modern inorganic chemistry

70 ENERGETICS

50r

g

0»O

45

40

35

30

25

20 -b.p of zinc-

15-

10

0-5 1-0 15 20 25 3-0 35

Figure 3,5. log 10 A f values for the reactions

Zn -f \Q:. - ZnO

CO + JO 2 = CO 2

When using log 10 X against 1/T graphs, in order to find the
temperature at which reduction becomes energetically feasible it is
necessary to determine the temperature at which the equilibrium
constant for the reduction indicates a displacement of the reaction
in favour of the metal.
Consider the reduction of zinc oxide, by carbon monoxide. The
equations are:

1. Zn -

CO

ZnO