<s>
A	O
depolarizer	B-Algorithm
or	O
depolariser	B-Algorithm
,	O
in	O
electrochemistry	O
,	O
according	O
to	O
an	O
IUPAC	O
definition	O
,	O
is	O
a	O
synonym	O
of	O
electroactive	O
substance	O
,	O
i.e.	O
,	O
a	O
substance	O
which	O
changes	O
its	O
oxidation	O
state	O
,	O
or	O
partakes	O
in	O
a	O
formation	O
or	O
breaking	O
of	O
chemical	O
bonds	O
,	O
in	O
a	O
charge-transfer	O
step	O
of	O
an	O
electrochemical	O
reaction	O
.	O
</s>
<s>
In	O
the	O
battery	O
industry	O
,	O
the	O
term	O
"	O
depolarizer	B-Algorithm
"	O
has	O
been	O
used	O
to	O
denote	O
a	O
substance	O
used	O
in	O
a	O
primary	B-Algorithm
cell	I-Algorithm
to	O
prevent	O
buildup	O
of	O
hydrogen	O
gas	O
bubbles	O
.	O
</s>
<s>
A	O
battery	O
depolarizer	B-Algorithm
takes	O
up	O
electrons	O
during	O
discharge	O
of	O
the	O
cell	O
;	O
therefore	O
,	O
it	O
is	O
always	O
an	O
oxidizing	O
agent	O
.	O
</s>
<s>
The	O
term	O
"	O
depolarizer	B-Algorithm
"	O
can	O
be	O
considered	O
as	O
outdated	O
or	O
misleading	O
,	O
since	O
it	O
is	O
based	O
on	O
the	O
concept	O
of	O
"	O
polarization	O
"	O
which	O
is	O
hardly	O
realistic	O
in	O
many	O
cases	O
.	O
</s>
<s>
Depolarizers	B-Algorithm
are	O
substances	O
which	O
are	O
intended	O
to	O
remove	O
the	O
hydrogen	O
,	O
and	O
therefore	O
,	O
they	O
help	O
to	O
keep	O
the	O
voltage	O
at	O
a	O
high	O
level	O
.	O
</s>
<s>
However	O
,	O
this	O
concept	O
is	O
outdated	O
,	O
since	O
if	O
enough	O
depolarizer	B-Algorithm
is	O
present	O
,	O
it	O
will	O
react	O
directly	O
in	O
most	O
cases	O
by	O
getting	O
electrons	O
from	O
the	O
positive	O
plate	O
of	O
the	O
galvanic	O
cell	O
,	O
i.e.	O
</s>
<s>
Therefore	O
,	O
the	O
original	O
concept	O
of	O
polarization	O
does	O
not	O
apply	O
to	O
most	O
batteries	O
,	O
and	O
the	O
depolarizer	B-Algorithm
does	O
not	O
react	O
with	O
hydrogen	O
as	O
H2	O
.	O
</s>
<s>
Many	O
different	O
substances	O
have	O
been	O
used	O
as	O
depolarizers	B-Algorithm
;	O
the	O
most	O
notable	O
are	O
listed	O
below	O
.	O
</s>
<s>
These	O
oxidize	B-Operating_System
the	O
hydrogen	O
to	O
water	O
.	O
</s>
<s>
Nitric	O
and	O
chromic	O
acids	O
are	O
powerful	O
oxidizing	O
agents	O
,	O
and	O
effective	O
depolarizers	B-Algorithm
,	O
but	O
their	O
hazardous	O
nature	O
makes	O
them	O
unsuitable	O
for	O
general	O
use	O
.	O
</s>
<s>
Manganese	O
dioxide	O
is	O
,	O
therefore	O
,	O
the	O
most	O
widely	O
used	O
depolarizer	B-Algorithm
.	O
</s>
