DOC.
2
15
2nd
partial
process:
The amount
of
dissolved metal that
has
thus
been
moved
electrolytically
from
z1 to
z2
we now move
back
mechanically
infinitely
slowly
from
z2
to
z1.
First of all, it is evident that the
process
is
strictly
reversible,
since all steps
are
imagined
to
proceed
infinitely
slowly,
i.e., the
process
is
compounded
of
(ideal)
states of
equilibrium.
For such
a
process
the
second
law
requires
that the total
amount
of heat
supplied to
the
system
during
the
cyclic
process
shall vanish.
In
conjunction
with the
second
law,
the first
law
requires
that the
sum
of all other
energies supplied
to
the
system
during
the
cyclic
process
shall vanish.
During
the first partial
process
the
amount
of electric
work supplied
is
-nE(II2
-
II1)
,
where
II2
and
II1
denote the electric potentials
of
the electrodes.
During
the
second
partial
process
[z1z2
Kdz
is
supplied, where
K
is the force
acting in the positive
z-direction
that
is
required
for the
nm
metal
ions that
are
to
be
moved,
and
which
are now
in
the metallic
state, to
keep
them at rest
at
an
arbitrary location
z.
It is
easily
seen
that the
following
equation
will hold for
K:
dP
dp
0
K
-
n
-t^m
-
n
v
~~t~
=
0
m
dz
m m
dz
Here
vm
denotes
the
volume
of
one
metal
ion
in the metallic
state.
Hence
the
above
work
takes
on
the value
£
1
K.dz
=
-
*2
rz2
Zl
dP
m
dp0
n
-1-
+ n
v
~i-
m
dz
m m
dz
dz
n
[{P
-
P
)
+ v
{p
-
p )]
,
w
ml
m
°2
°1