24
DIFFERENCE IN
POTENTIALS
Subtracting
these
two
expressions and taking
into
account
the results
found
in
§5,
one
obtains
The
extension
required
if the solvents
are
mixtures is
easily obtained
as
in
§5.
The
values
of
the left-hand side
of
this
equation
are
obtained directly
from experiment.
The
determination
of
the first
term
of the
right-hand
side
will
be
dealt with in the
next
paragraph;
for the time
being,
let it
only be
said that this
term
can
be
calculated
from
the
concentrations
used and
the
molecular conductivities of the
respective
ions for the
respective
solvent,
provided
the
arrangement
has been suitably chosen.
Thus
the
equation
makes
it
possible to
calculate the
second term
on
the
right-hand side.
This
we
utilize
to
determine the
constant
c
for the metal ions
and
to
test
our
hypotheses.
We
always
use
the
same
two
solvents
in
a
series of
experiments
of the kind
described.
Then
for the
whole experimental
series the
quantity
[10]
1
{c^2)^2)
"
c)£)vY)}
~
k
~
const.
Hence,
if
one
puts
n1/nm1
=
E1,
etc., to
be
equal
the
valency
of the
first
etc.
metal
ion,
the last
term
calculated
of the right-hand side will
be
a
relative
measure
for the
quantity
If
one
thus
examines
the combinations
of
all
electrode
metals
pair
by
pair,
one
obtains the
quantities
(2)
_
)
-
rC
11 -1
rC
n
{(Kg
"
Ji)
(2)
_
(x2«T1)(1)}
- E
2
m m m
m1
n
2 71
l
w,
m
1
1