what chemical is in AODISC hydrogen peroxide neutralizer?
Anonymous
AODISC hydrogen peroxide neutralizer?
It's a small disk with fins that sits
at the bottom of the contact lens cleaning
container. When H2O2 is added, it gradually
causes the H2O2 to bubble and become pH neutral
so it doesn't sting the eyes.
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Greatest Prime
anon...@anonymous.anonymous wrote on 5/18/01 10:02 AM:
I have no idea. But just consider some fundamental chemistry. Hydrogen
peroxide turns into water just by itself. An inhibitor is added to what you
buy in the store to prevent that, Almost anything will catalyze the
conversion into water. Saliva, blood, or manganese dioxide are some.
Bill
Dan Abel
<anon...@anonymous.anonymous> wrote:
> Anyone know what chemical is in the
> AODISC hydrogen peroxide neutralizer?
> It's a small disk with fins that sits
> at the bottom of the contact lens cleaning
> container. When H2O2 is added, it gradually
> causes the H2O2 to bubble and become pH neutral
> so it doesn't sting the eyes.
I'm not certain, but I believe that technically it is not a chemical, but
a catalyst. It is not consumed in the reaction, but causes it. How they
make it wear out I don't know, but I don't believe it is consumed.
Hydrogen peroxide is simply water with extra oxygen. The decomposition
produces free oxygen which leaves plain water in the vial.
--
Dan Abel
Sonoma State University
AIS
ab...@sonoma.edu
http://www.sonoma.edu/IT/AIS/people/Abel.html
Mike Tyner
-MT
"Anonymous" <anon...@anonymous.anonymous> wrote in message
news:3B0555AD...@optonline.net...
Anonymous
in the packaging but I'm not
sure exactly how it works chemically.
If it's a catalyst and isn't actually
used up in the reaction, how come after
a while, the AODISC "wears" out.
It no longer neutralizes and the disc's
greyish coating wears off exposing the
white plastic of the AODISC?
Mike Tyner wrote:
>
> I'm sure it's platinum.
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Mike Tyner
chemistry. In some cases it has to be very hot, but peroxide is "fragile"
and the platinum surface is all that is necessary to promote its breakup.
I'm not sure what happens to the platinum. It gets coated or contaminated
somehow, as you can see by the decrease in bubbles. I didn't realize the
coating disappears, exposing the white plastic. I don't believe the platinum
dissolves away.
-MT
"Anonymous" <anon...@anonymous.anonymous> wrote in message
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Greatest Prime
anon...@anonymous.anonymous wrote on 5/19/01 1:34 AM:
I guess that it is possible that it is platinum. It would be deposited very
thinly on a large area substrate. I have a catalytic heater that uses
(before the big scare) platinized asbestos. It should not be necessary to
use platinum because there are many cheaper and suitable catalysts.
Bill
bl...@table.blackguild.nos.pam.com
>> Anyone know what chemical is in the
>> AODISC hydrogen peroxide neutralizer?
>> It's a small disk with fins that sits
>> at the bottom of the contact lens cleaning
>> container. When H2O2 is added, it gradually
>> causes the H2O2 to bubble and become pH neutral
>> so it doesn't sting the eyes.
> I'm not certain, but I believe that technically it is not a chemical, but
> a catalyst.
Technically, catalysts are still chemicals, although
not consumed in the reaction they facilitate. Most
things are chemicals, really :-) But as you and others
say, there are plenty of things that will accelerate
the decomposition of H2O2 into water & oxygen without
themselves being consumed; I'd assume the catalyst is
something pretty inert.
--
Geoffrey Brent
Reply email: g.brent at student.unsw.edu.au
Someone who knew how to edit responses properly
wouldn't be quoting this .sig.
bl...@table.blackguild.nos.pam.com
> They mentioned platinum
> in the packaging but I'm not
> sure exactly how it works chemically.
Ooh, rates of reaction and chemistry!
Platinum is used as a catalyst for quite a variety
of chemical reactions. There are two basic ways in
which catalysts work, IIRC. First way is to allow
lower-energy intermediate states for the desired
reaction - if you think of reacting chemicals as
trying to push a car over a hill, a catalyst
effectively lowers that hill so the slope is easier.
The second way (hope I haven't missed any out) is to
increase the rate of contact between reagents. If
you can attract the reagents to a two-dimensional
surface (e.g. the surface of a piece of platinum)
you can substantially increase the chances that they'll
interact, and so speed up the reaction process. I don't
recall the mechanism by which H202 normally decomposes
but I suspect it involves interaction with H+ or OH-
ions, so a platinum catalyst might speed this process
too.
> If it's a catalyst and isn't actually
> used up in the reaction, how come after
> a while, the AODISC "wears" out.
> It no longer neutralizes and the disc's
> greyish coating wears off exposing the
> white plastic of the AODISC?
In theory, catalysts aren't used up in reactions. In
practice, they eventually get corroded, or worn away,
or simply coated in crud that stops them from working.
Pick whichever of these seems most plausible (probably
not the first, given how inert Pt is.)