semi off-topic: how to clean ferrichloride stains

01 Mar 2008 12:22:40

Ivan

First of all, sorry on OffTopic. My question is how to clean stains made by
ferrichloride? Thanks!

PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect.

01 Mar 2008 03:36:33

MooseFET

Re: semi off-topic: how to clean ferrichloride stains

"Ivan" <ikalafat_makni@gmail.com > wrote in message
news:fqbea1$puf$1@ss408.t-com.hr...
> First of all, sorry on OffTopic. My question is how to clean stains made
> by
> ferrichloride? Thanks!
>
> PS: Acetone and diulent (thinner) doesn't help, benzene also has no
> effect.
>

Stain = Oxidation only appears on the surface, you have to sand it off a bit
before applying Acetone.

01 Mar 2008 08:10:45

www.ningbo-electric.com

Re: semi off-topic: how to clean ferrichloride stains

On Mar 1, 7:22=A0pm, "Ivan" <ikalafat_ma...@gmail.com > wrote:
> First of all, sorry on OffTopic. My question is how to clean stains made b=
y
> ferrichloride? Thanks!
>
> PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect=
.

Hope you can quickly find how to clean stains .
Btw, know something about the manufacturer of electirc products:
China air source treatment,pressure regulating filter ,atomizer
lubricator,oil sprayer,two-point,three-point F.R.L
combination,pressure regulating valve,filter
regulator,SDA,CQ2B,CJ2B,CM2B thin type cylinder,MAL aluminum alloy
mini,pneumatic cylinder,CXSM double,single acting cylinder,double
acting,STMB,CX2 skid platform,solenoid valve,pneumatic magnetic
valve,hand valve,cylinder manifold,
www.ningbo-electric.com

01 Mar 2008 10:41:43

John Fields

Re: semi off-topic: how to clean ferrichloride stains

On Sat, 1 Mar 2008 08:10:45 -0800 (PST), "www.ningbo-electric.com"
<alexyfy@gmail.com > wrote:

>On Mar 1, 7:22 pm, "Ivan" <ikalafat_ma...@gmail.com> wrote:
>> First of all, sorry on OffTopic. My question is how to clean stains made by
>> ferrichloride? Thanks!
>>
>> PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect.
>
>Hope you can quickly find how to clean stains .
>Btw, know something about the manufacturer of electirc products:
>China air source treatment,pressure regulating filter ,atomizer
>lubricator,oil sprayer,two-point,three-point F.R.L
>combination,pressure regulating valve,filter
>regulator,SDA,CQ2B,CJ2B,CM2B thin type cylinder,MAL aluminum alloy
>mini,pneumatic cylinder,CXSM double,single acting cylinder,double
>acting,STMB,CX2 skid platform,solenoid valve,pneumatic magnetic
>valve,hand valve,cylinder manifold,
>www.ningbo-electric.com

---
Take it somewhere else, you SPAMming piece of shit.

--
JF

01 Mar 2008 10:47:59

Tim Williams

Re: semi off-topic: how to clean ferrichloride stains

Acid. Try vinegar or oxalic acid. Think rust remover. For that matter,
CLR sounds like yet another option.

Tim

--
Deep Fryer: A very philosophical monk.
Website @ http://webpages.charter.net/dawill/tmoranwms

"Ivan" <ikalafat_makni@gmail.com > wrote in message
news:fqbea1$puf$1@ss408.t-com.hr...
> First of all, sorry on OffTopic. My question is how to clean stains made
by
> ferrichloride? Thanks!
>
> PS: Acetone and diulent (thinner) doesn't help, benzene also has no
effect.
>
>

01 Mar 2008 09:04:03

J.A. Legris

Re: semi off-topic: how to clean ferrichloride stains

On Mar 1, 6:22=A0am, "Ivan" <ikalafat_ma...@gmail.com > wrote:
> First of all, sorry on OffTopic. My question is how to clean stains made b=
y
> ferrichloride? Thanks!
>
> PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect=
.

=46rom the blog of a very smart guy, Michael Covington:

( http://www.covingtoninnovations.com/michael/blog/0712/index.html#071223B
)

"The other day, in our robotics lab, I gave a demonstration of making
a printed circuit board. I used ferric chloride etchant because it
doesn't require heating.

Unfortunately, I spilled a few drops of the etchant on a vinyl anti-
static mat that was somewhat porous. As you know, ferric chloride is
yellowish-brown, a lot like rust, and tends to stain everything it
touches. So despite some cleanup attempts with water and various
cleaning products, there was a stain.

Today (Dec. 22) I got the stain out, mostly. I made a paste of citric
acid and water and left it on the stain for 2 hours. That removed
about 80% of the stain.

I may go at it again with citric acid and hot water. I'm told that
oxalic acid is more effective, and that it's sold as DAP Wood Bleach,
but I didn't have any.

Addendum: I'm told that oxalic acid is also the active ingredient in
Bar Keepers Friend powder (not liquid). If so, this should be just the
thing for removing FeCl stains.

Another addendum: This source indicates that FeCl stains can be
decolorized by phosphoric acid, i.e., Coca-Cola. I'll have to try
that. As close as the nearest vending machine!"

--
Joe

01 Mar 2008 11:03:00

D from BC

Re: semi off-topic: how to clean ferrichloride stains

On Sat, 1 Mar 2008 09:04:03 -0800 (PST), "J.A. Legris"
<jalegris@sympatico.ca > wrote:

>On Mar 1, 6:22 am, "Ivan" <ikalafat_ma...@gmail.com> wrote:
>> First of all, sorry on OffTopic. My question is how to clean stains made by
>> ferrichloride? Thanks!
>>
>> PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect.
>
>From the blog of a very smart guy, Michael Covington:
>
>( http://www.covingtoninnovations.com/michael/blog/0712/index.html#071223B
>)
>
>"The other day, in our robotics lab, I gave a demonstration of making
>a printed circuit board. I used ferric chloride etchant because it
>doesn't require heating.

(I microwave Ferric Chloride for really fast etching..and pressurize
it too.)

>
>Unfortunately, I spilled a few drops of the etchant on a vinyl anti-
>static mat that was somewhat porous. As you know, ferric chloride is
>yellowish-brown, a lot like rust, and tends to stain everything it
>touches. So despite some cleanup attempts with water and various
>cleaning products, there was a stain.
>
>Today (Dec. 22) I got the stain out, mostly. I made a paste of citric
>acid and water and left it on the stain for 2 hours. That removed
>about 80% of the stain.
>
>I may go at it again with citric acid and hot water. I'm told that
>oxalic acid is more effective, and that it's sold as DAP Wood Bleach,
>but I didn't have any.
>
>Addendum: I'm told that oxalic acid is also the active ingredient in
>Bar Keepers Friend powder (not liquid). If so, this should be just the
>thing for removing FeCl stains.
>
>Another addendum: This source indicates that FeCl stains can be
>decolorized by phosphoric acid, i.e., Coca-Cola. I'll have to try
>that. As close as the nearest vending machine!"

Interesting but I avoid cleaning. :P
If something gets stained, too bad. Chuck it in the garbage... Unless
you splattered Ferric Chloride all over your new spectrum analyzer. :P

I use Ferric Chloride like a neat chemist. No mess.
Ammonium Persulfate doesn't make yellowish stains.
However, Ammonium P. can eat rugs.. Made a nasty hole one time :P

D from BC
British Columbia
Canada.

01 Mar 2008 11:42:33

Tom Bruhns

Re: semi off-topic: how to clean ferrichloride stains

On Mar 1, 3:22 am, "Ivan" <ikalafat_ma...@gmail.com > wrote:
> First of all, sorry on OffTopic. My question is how to clean stains made by
> ferrichloride? Thanks!
>
> PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect.

Doesn't seem so off-topic to me...assuming of course that you were
using the ferric chloride to etch something electronic and not
something else. ;-)

As others have pointed out, acid solvents work well on ferrous/ferric
ions. Both ferric and ferrous hydroxide have very low solubility, but
the acid removes the hydroxide part and lets the iron go into
solution. If the thing you're cleaning can stand it, you can use
(dilute) hydrochloric acid (muriatic acid), commonly available very
cheaply at places that have masonry supplies, as it's used to clean up
mortar splashes and the like. It works really fast to remove iron
stains, generally won't hurt anything you'd put ferric chloride in,
but like ferric chloride is best kept away from skin. I find it's
also good to have a little HCl around to add to the ferric chloride
solution, to insure the ferric stays in solution. Acid also keeps
cuprous ion in solution.

I believe Zud is another cleanser that works well on iron stains: as
I recall, it has a little oxalic acid in it.

Cheers,
Tom

01 Mar 2008 14:10:13

The Phantom

Re: semi off-topic: how to clean ferrichloride stains

On Sat, 1 Mar 2008 12:22:40 +0100, "Ivan" <ikalafat_makni@gmail.com > wrote:

>First of all, sorry on OffTopic. My question is how to clean stains made by
>ferrichloride? Thanks!
>
>PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect.
>
Get some commercial rust remover at the hardware store.

01 Mar 2008 18:02:49

Phil Hobbs

Re: semi off-topic: how to clean ferrichloride stains

J.A. Legris wrote:
> On Mar 1, 6:22 am, "Ivan" <ikalafat_ma...@gmail.com> wrote:
>> First of all, sorry on OffTopic. My question is how to clean stains made by
>> ferrichloride? Thanks!
>>
>> PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect..
>
> From the blog of a very smart guy, Michael Covington:
>
> ( http://www.covingtoninnovations.com/michael/blog/0712/index.html#071223B
> )
>
> "The other day, in our robotics lab, I gave a demonstration of making
> a printed circuit board. I used ferric chloride etchant because it
> doesn't require heating.
>
> Unfortunately, I spilled a few drops of the etchant on a vinyl anti-
> static mat that was somewhat porous. As you know, ferric chloride is
> yellowish-brown, a lot like rust, and tends to stain everything it
> touches. So despite some cleanup attempts with water and various
> cleaning products, there was a stain.
>
> Today (Dec. 22) I got the stain out, mostly. I made a paste of citric
> acid and water and left it on the stain for 2 hours. That removed
> about 80% of the stain.
>
> I may go at it again with citric acid and hot water. I'm told that
> oxalic acid is more effective, and that it's sold as DAP Wood Bleach,
> but I didn't have any.
>
> Addendum: I'm told that oxalic acid is also the active ingredient in
> Bar Keepers Friend powder (not liquid). If so, this should be just the
> thing for removing FeCl stains.
>
> Another addendum: This source indicates that FeCl stains can be
> decolorized by phosphoric acid, i.e., Coca-Cola. I'll have to try
> that. As close as the nearest vending machine!"
>
> --
> Joe

Rust stains on sinks can be got rid of with Naval Jelly, which is
jellied phosphoric acid. Works right away.

Cheers,

Phil Hobbs

01 Mar 2008 17:58:06

Robert Baer

Re: semi off-topic: how to clean ferrichloride stains

Ivan wrote:
> First of all, sorry on OffTopic. My question is how to clean stains made by
> ferrichloride? Thanks!
>
> PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect.
>
>
Use a deadly poison: Oxalic acid.

01 Mar 2008 22:49:14

JosephKK

Re: semi off-topic: how to clean ferrichloride stains

D from BC wrote:
> On Sat, 1 Mar 2008 09:04:03 -0800 (PST), "J.A. Legris"
> <jalegris@sympatico.ca> wrote:
>
>> On Mar 1, 6:22 am, "Ivan" <ikalafat_ma...@gmail.com> wrote:
>>> First of all, sorry on OffTopic. My question is how to clean stains made by
>>> ferrichloride? Thanks!
>>>
>>> PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect.
>>From the blog of a very smart guy, Michael Covington:
>> ( http://www.covingtoninnovations.com/michael/blog/0712/index.html#071223B
>> )
>>
>> "The other day, in our robotics lab, I gave a demonstration of making
>> a printed circuit board. I used ferric chloride etchant because it
>> doesn't require heating.
>
> (I microwave Ferric Chloride for really fast etching..and pressurize
> it too.)
>
>> Unfortunately, I spilled a few drops of the etchant on a vinyl anti-
>> static mat that was somewhat porous. As you know, ferric chloride is
>> yellowish-brown, a lot like rust, and tends to stain everything it
>> touches. So despite some cleanup attempts with water and various
>> cleaning products, there was a stain.
>>
>> Today (Dec. 22) I got the stain out, mostly. I made a paste of citric
>> acid and water and left it on the stain for 2 hours. That removed
>> about 80% of the stain.
>>
>> I may go at it again with citric acid and hot water. I'm told that
>> oxalic acid is more effective, and that it's sold as DAP Wood Bleach,
>> but I didn't have any.
>>
>> Addendum: I'm told that oxalic acid is also the active ingredient in
>> Bar Keepers Friend powder (not liquid). If so, this should be just the
>> thing for removing FeCl stains.
>>
>> Another addendum: This source indicates that FeCl stains can be
>> decolorized by phosphoric acid, i.e., Coca-Cola. I'll have to try
>> that. As close as the nearest vending machine!"
>
> Interesting but I avoid cleaning. :P
> If something gets stained, too bad. Chuck it in the garbage... Unless
> you splattered Ferric Chloride all over your new spectrum analyzer. :P
>
> I use Ferric Chloride like a neat chemist. No mess.
> Ammonium Persulfate doesn't make yellowish stains.
> However, Ammonium P. can eat rugs.. Made a nasty hole one time :P
>
>
> D from BC
> British Columbia
> Canada.

Any good reducing agent should do just fine.

02 Mar 2008 00:02:49

Re: semi off-topic: how to clean ferrichloride stains

02 Mar 2008 03:27:28

Leon

Re: semi off-topic: how to clean ferrichloride stains

On 2 Mar, 08:02, a7yvm109gf...@netzero.com wrote:
> On Mar 1, 6:22 am, "Ivan" <ikalafat_ma...@gmail.com> wrote:
>
> > First of all, sorry on OffTopic. My question is how to clean stains made by
> > ferrichloride? Thanks!
>
> > PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect.
>
> Baking soda?

As previously suggested, oxalic acid is the stuff to use. Rhubarb
leaves contain it, BTW.

Leon

02 Mar 2008 10:42:27

JosephKK

Re: semi off-topic: how to clean ferrichloride stains

a7yvm109gf5d1@netzero.com wrote:
> On Mar 1, 6:22 am, "Ivan" <ikalafat_ma...@gmail.com> wrote:
>> First of all, sorry on OffTopic. My question is how to clean stains made by
>> ferrichloride? Thanks!
>>
>> PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect.
>
> Baking soda?

I don't think so, but some judicious googling should find you some.
Preferably less expensive that sodium bismuthate.

02 Mar 2008 18:49:13

JosephKK

Re: semi off-topic: how to clean ferrichloride stains

Leon wrote:
> On 2 Mar, 08:02, a7yvm109gf...@netzero.com wrote:
>> On Mar 1, 6:22 am, "Ivan" <ikalafat_ma...@gmail.com> wrote:
>>
>>> First of all, sorry on OffTopic. My question is how to clean stains made by
>>> ferrichloride? Thanks!
>>> PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect.
>> Baking soda?
>
> As previously suggested, oxalic acid is the stuff to use. Rhubarb
> leaves contain it, BTW.
>
> Leon

Yep. Also sodium sulfite (not sulfate) is good.

02 Mar 2008 16:37:22

Dave Platt

Re: semi off-topic: how to clean ferrichloride stains

>First of all, sorry on OffTopic. My question is how to clean stains made by
>ferrichloride? Thanks!

One commercial product made for this purpose (sold by Mega
Electronics) consists of 100% oxalic acid powder. 100 grams of
powder, dissolved in 500ml of warm water, is the recommended starting
concentration). Immerse items and soak until the stain is removed.

For other sorts of iron stains (e.g. rust stains from a nail left a
pocket) I've seen citric acid recommended.

In both cases, I believe that the principle is that the acid reduces
(de-oxidizes) the iron, converting it back to a soluble form that can
then be rinsed away.

Apply all appropriate safety precautions when working with these sots
of organic acids (protective gloves and goggles for starters)!

>PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect.

No, I don't think that organic solvents would be helpful.

--
Dave Platt <dplatt@radagast.org > AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

03 Mar 2008 10:41:19

Tom Bruhns

Re: semi off-topic: how to clean ferrichloride stains

On Mar 2, 4:37 pm, dpl...@radagast.org (Dave Platt) wrote:
...
> In both cases, I believe that the principle is that the acid reduces
> (de-oxidizes) the iron, converting it back to a soluble form that can
> then be rinsed away.

It is, I believe, much simpler than that. It's simply that ferric and
ferrous hydroxides each have such low solubility products that they
don't dissolve readily in neutral water whose [OH-] is about 10^-7.
By acidifying the water with a weak acid, you reduce the [OH-] to
perhaps 10^-13 or 10^-14. That's a result of the characteristic of
water that maintains [H+]*[OH-] at about 10^-14. That lets the ferric
and ferrous dissolve much more readily.

Cheers,
Tom

04 Mar 2008 05:31:25

JosephKK

Re: semi off-topic: how to clean ferrichloride stains

On Mon, 3 Mar 2008 10:41:19 -0800 (PST), Tom Bruhns <k7itm@msn.com >
wrote:

>On Mar 2, 4:37 pm, dpl...@radagast.org (Dave Platt) wrote:
>...
>> In both cases, I believe that the principle is that the acid reduces
>> (de-oxidizes) the iron, converting it back to a soluble form that can
>> then be rinsed away.
>
>It is, I believe, much simpler than that. It's simply that ferric and
>ferrous hydroxides each have such low solubility products that they
>don't dissolve readily in neutral water whose [OH-] is about 10^-7.
>By acidifying the water with a weak acid, you reduce the [OH-] to
>perhaps 10^-13 or 10^-14. That's a result of the characteristic of
>water that maintains [H+]*[OH-] at about 10^-14. That lets the ferric
>and ferrous dissolve much more readily.
>
>Cheers,
>Tom

PH per se is a separate issue from redox. The most effective way to
handle ferric chloride is by reduction. In well done cases you will
get fe+2 in solution (or possibly if sufficiently extreme cases micro
powder elemental iron in suspension, temporarily). If appropriate
ionic species are provided you can remove most of the Cl- ions.

04 Mar 2008 09:09:45

Tim Williams

Re: semi off-topic: how to clean ferrichloride stains

"JosephKK" <quiettechblue@yahoo.com > wrote in message
news:qdnps3pn069244929k8p7qo9sfom1hkp84@4ax.com...
> PH per se is a separate issue from redox.

It is, but they are all equilibria. ;-)

Since we're going to invoke chemistry, I'm just going to go overboard and
rattle off some stuff here: ;-)

Hydroxy:
Fe(OH)3 <-- > Fe(3+) + 3 OH- pKs = 38.8
Fe(3+) + H2O <-- > FeOH(2+) + H+ pKa = 2.19
Fe(OH)(2+) + H2O <-- > Fe(OH)2(+) + H+ pKa = 2.41
Fe(OH)2(+) + H2O <-- > Fe(OH)3(aq) + H+ pKa = 7.97
(Note this doesn't include the solubility of the Fe(OH)3 species.)
Chelates:
Fe(3+) + EDTA(4-) <-- > [FeEDTA]- pKf = -25.1
Chlorides:
Fe(3+) + Cl- <-- > FeCl(2+) pKf1 = -1.48
FeCl(2+) + Cl- <-- > FeCl2(+) pKf2 = -0.65
FeCl2(+) + Cl- <-- > FeCl3(aq) pKf3 = 1.00
Oxalates:
Fe(3+) + C2O4(2-) <-- > [FeC2O4]+ pKf1 = -7.54
[FeC2O4]+ + C2O4(2-) <-- > [Fe(C2O4)2)]- pKf2 = -7.05
[Fe(C2O4)2]- + C2O4(2-) <-- > [Fe(C2O4)3)](3-) pKf3 = -5.41
(So total pKf = 20.00.)
Citrate:
Fe(3+) + Cit(3-) <-- > [FeCit](aq) pKf = -11.8
Redox:
Fe(3+) + e- <-- > Fe(2+) Eo = 0.771 V
SO4(2-) + H2O + 2e- <-- > SO3(2-) + 2OH- Eo = -0.936 V
(Hmm, that's in alkali.)

So: Fe(OH)3 is damned insoluble; Fe(3+) is pretty acidic (as aqueous ions
go); FeCl3 is somewhat more soluble, but it still takes a lot of chloride
and acid to overcome the insolubility of Fe(OH)3; chelates like EDTA, et
al., oxalate, citrate, etc. grab on real tight, solvating iron well; and a
variety of reducing agents will suffice, but only if you get the iron into
solution to react with it.

Tim

--
Deep Fryer: A very philosophical monk.
Website @ http://webpages.charter.net/dawill/tmoranwms

04 Mar 2008 17:06:08

Paul Hovnanian P.E.

Re: semi off-topic: how to clean ferrichloride stains

Ivan wrote:
>
> First of all, sorry on OffTopic. My question is how to clean stains made by
> ferrichloride? Thanks!
>
> PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect.

What did you stain?

I have some ideas, but they may not work well on the cat.

--
Paul Hovnanian mailto:Paul@Hovnanian.com
------------------------------------------------------------------
If everything is coming your way then you're in the wrong lane.

04 Mar 2008 20:29:19

Michael A. Terrell

Re: semi off-topic: how to clean ferrichloride stains

"Paul Hovnanian P.E." wrote:
>
> Ivan wrote:
> >
> > First of all, sorry on OffTopic. My question is how to clean stains made by
> > ferrichloride? Thanks!
> >
> > PS: Acetone and diulent (thinner) doesn't help, benzene also has no effect.
>
> What did you stain?
>
> I have some ideas, but they may not work well on the cat.

The cat? How about a belt sander? ;-)

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

05 Mar 2008 03:43:16

JosephKK

Re: semi off-topic: how to clean ferrichloride stains

On Tue, 4 Mar 2008 09:09:45 -0600, "Tim Williams"
<tmoranwms@gmail.com > wrote:

>"JosephKK" <quiettechblue@yahoo.com> wrote in message
>news:qdnps3pn069244929k8p7qo9sfom1hkp84@4ax.com...
>> PH per se is a separate issue from redox.
>
>It is, but they are all equilibria. ;-)
>
>Since we're going to invoke chemistry, I'm just going to go overboard and
>rattle off some stuff here: ;-)
>
>Hydroxy:
>Fe(OH)3 <--> Fe(3+) + 3 OH- pKs = 38.8
>Fe(3+) + H2O <--> FeOH(2+) + H+ pKa = 2.19
>Fe(OH)(2+) + H2O <--> Fe(OH)2(+) + H+ pKa = 2.41
>Fe(OH)2(+) + H2O <--> Fe(OH)3(aq) + H+ pKa = 7.97
>(Note this doesn't include the solubility of the Fe(OH)3 species.)
>Chelates:
>Fe(3+) + EDTA(4-) <--> [FeEDTA]- pKf = -25.1
>Chlorides:
>Fe(3+) + Cl- <--> FeCl(2+) pKf1 = -1.48
>FeCl(2+) + Cl- <--> FeCl2(+) pKf2 = -0.65
>FeCl2(+) + Cl- <--> FeCl3(aq) pKf3 = 1.00
>Oxalates:
>Fe(3+) + C2O4(2-) <--> [FeC2O4]+ pKf1 = -7.54
>[FeC2O4]+ + C2O4(2-) <--> [Fe(C2O4)2)]- pKf2 = -7.05
>[Fe(C2O4)2]- + C2O4(2-) <--> [Fe(C2O4)3)](3-) pKf3 = -5.41
>(So total pKf = 20.00.)
>Citrate:
>Fe(3+) + Cit(3-) <--> [FeCit](aq) pKf = -11.8
>Redox:
>Fe(3+) + e- <--> Fe(2+) Eo = 0.771 V
>SO4(2-) + H2O + 2e- <--> SO3(2-) + 2OH- Eo = -0.936 V
>(Hmm, that's in alkali.)
>
>So: Fe(OH)3 is damned insoluble; Fe(3+) is pretty acidic (as aqueous ions
>go); FeCl3 is somewhat more soluble, but it still takes a lot of chloride
>and acid to overcome the insolubility of Fe(OH)3; chelates like EDTA, et
>al., oxalate, citrate, etc. grab on real tight, solvating iron well; and a
>variety of reducing agents will suffice, but only if you get the iron into
>solution to react with it.
>
>Tim

I don't suppose that you would consider trying to analyze the impact
of sodium bismuthate and sodium bisulfite on the ferrous chloride /
ferric chloride / cuprous chloride / cupric chloride / ferric
hydroxide solutions.

Yes there is usually all those species and more when ferric chloride
is used as a copper echant.

05 Mar 2008 00:05:58

The Phantom

Re: semi off-topic: how to clean ferrichloride stains

On Wed, 05 Mar 2008 03:43:16 GMT, JosephKK <quiettechblue@yahoo.com > wrote:

>On Tue, 4 Mar 2008 09:09:45 -0600, "Tim Williams"
><tmoranwms@gmail.com> wrote:
>
>>"JosephKK" <quiettechblue@yahoo.com> wrote in message
>>news:qdnps3pn069244929k8p7qo9sfom1hkp84@4ax.com...
>>> PH per se is a separate issue from redox.
>>
>>It is, but they are all equilibria. ;-)
>>
>>Since we're going to invoke chemistry, I'm just going to go overboard and
>>rattle off some stuff here: ;-)
>>
>>Hydroxy:
>>Fe(OH)3 <--> Fe(3+) + 3 OH- pKs = 38.8
>>Fe(3+) + H2O <--> FeOH(2+) + H+ pKa = 2.19
>>Fe(OH)(2+) + H2O <--> Fe(OH)2(+) + H+ pKa = 2.41
>>Fe(OH)2(+) + H2O <--> Fe(OH)3(aq) + H+ pKa = 7.97
>>(Note this doesn't include the solubility of the Fe(OH)3 species.)
>>Chelates:
>>Fe(3+) + EDTA(4-) <--> [FeEDTA]- pKf = -25.1
>>Chlorides:
>>Fe(3+) + Cl- <--> FeCl(2+) pKf1 = -1.48
>>FeCl(2+) + Cl- <--> FeCl2(+) pKf2 = -0.65
>>FeCl2(+) + Cl- <--> FeCl3(aq) pKf3 = 1.00
>>Oxalates:
>>Fe(3+) + C2O4(2-) <--> [FeC2O4]+ pKf1 = -7.54
>>[FeC2O4]+ + C2O4(2-) <--> [Fe(C2O4)2)]- pKf2 = -7.05
>>[Fe(C2O4)2]- + C2O4(2-) <--> [Fe(C2O4)3)](3-) pKf3 = -5.41
>>(So total pKf = 20.00.)
>>Citrate:
>>Fe(3+) + Cit(3-) <--> [FeCit](aq) pKf = -11.8
>>Redox:
>>Fe(3+) + e- <--> Fe(2+) Eo = 0.771 V
>>SO4(2-) + H2O + 2e- <--> SO3(2-) + 2OH- Eo = -0.936 V
>>(Hmm, that's in alkali.)
>>
>>So: Fe(OH)3 is damned insoluble; Fe(3+) is pretty acidic (as aqueous ions
>>go); FeCl3 is somewhat more soluble, but it still takes a lot of chloride
>>and acid to overcome the insolubility of Fe(OH)3; chelates like EDTA, et
>>al., oxalate, citrate, etc. grab on real tight, solvating iron well; and a
>>variety of reducing agents will suffice, but only if you get the iron into
>>solution to react with it.
>>
>>Tim
>
>I don't suppose that you would consider trying to analyze the impact
>of sodium bismuthate and sodium bisulfite on the ferrous chloride /
>ferric chloride / cuprous chloride / cupric chloride / ferric

You must mean something else other than sodium bismuthate for a reducing
agent. It's a very strong oxidizing agent. See:
http://www.newi.ac.uk/buckleyc/titrat.htm

Maybe you're thinking of something like sodium dithionite.

>hydroxide solutions.
>
>Yes there is usually all those species and more when ferric chloride
>is used as a copper echant.

06 Mar 2008 00:21:09

Tim Williams

Re: semi off-topic: how to clean ferrichloride stains

"JosephKK" <quiettechblue@yahoo.com > wrote in message
news:tc5ss31fma1h083nplkucq9fr2mut9llm7@4ax.com...
> I don't suppose that you would consider trying to analyze the impact
> of sodium bismuthate and sodium bisulfite on the ferrous chloride /
> ferric chloride / cuprous chloride / cupric chloride / ferric
> hydroxide solutions.
>
> Yes there is usually all those species and more when ferric chloride
> is used as a copper echant.

The interesting thing about mixed oxidation state Fe/Cu complexes is, they
are indeed quite mixed! For instance, on mixing Fe(II) and Cu(II) chloride
solutions, you would not expect any reaction because Cu(II) is not strong
enough to oxidize Fe(II) very far. But a dark complex occurs, containing
Fe(II), Fe(III), Cu(I) and Cu(II).

Likewise, the Cu(I)Cl2(-) ion is colorless in solution and Cu(II)Cl4(2-) is
green, but on mixing them, an intensely deep brown complex occurs, possibly
containing a mixed ion Cl2-Cu-Cl2-Cu-Cl2 (the middle Cl- ions bridge the
Cu's), with each Cu approximately +1.5. When a colorless CuCl2(-) solution
is exposed to any small amount of air, it immediately becomes intensely
dark. Likewise, when a CuCl4(2-) solution is reduced (by copper metal, for
instance), it becomes dark, first dark green and then dark brown.

When the brown complex is diluted significantly, the [Cl-] concentration
drops and white CuCl precipitates, leaving a weak blue solution of
[Cu(H2O)6](2+) (probably with some Cl- ligands too, but not as many as in
the concentrated solution).

For such common elements, these chemistries are not actually very well
understood!

Tim

--
Deep Fryer: A very philosophical monk.
Website @ http://webpages.charter.net/dawill/tmoranwms

07 Mar 2008 02:20:24

JosephKK

Re: semi off-topic: how to clean ferrichloride stains

On Wed, 05 Mar 2008 00:05:58 -0800, The Phantom <phantom@aol.com >
wrote:

>On Wed, 05 Mar 2008 03:43:16 GMT, JosephKK <quiettechblue@yahoo.com> wrote:
>
>>On Tue, 4 Mar 2008 09:09:45 -0600, "Tim Williams"
>><tmoranwms@gmail.com> wrote:
>>
>>>"JosephKK" <quiettechblue@yahoo.com> wrote in message
>>>news:qdnps3pn069244929k8p7qo9sfom1hkp84@4ax.com...
>>>> PH per se is a separate issue from redox.
>>>
>>>It is, but they are all equilibria. ;-)
>>>
>>>Since we're going to invoke chemistry, I'm just going to go overboard and
>>>rattle off some stuff here: ;-)
>>>
>>>Hydroxy:
>>>Fe(OH)3 <--> Fe(3+) + 3 OH- pKs = 38.8
>>>Fe(3+) + H2O <--> FeOH(2+) + H+ pKa = 2.19
>>>Fe(OH)(2+) + H2O <--> Fe(OH)2(+) + H+ pKa = 2.41
>>>Fe(OH)2(+) + H2O <--> Fe(OH)3(aq) + H+ pKa = 7.97
>>>(Note this doesn't include the solubility of the Fe(OH)3 species.)
>>>Chelates:
>>>Fe(3+) + EDTA(4-) <--> [FeEDTA]- pKf = -25.1
>>>Chlorides:
>>>Fe(3+) + Cl- <--> FeCl(2+) pKf1 = -1.48
>>>FeCl(2+) + Cl- <--> FeCl2(+) pKf2 = -0.65
>>>FeCl2(+) + Cl- <--> FeCl3(aq) pKf3 = 1.00
>>>Oxalates:
>>>Fe(3+) + C2O4(2-) <--> [FeC2O4]+ pKf1 = -7.54
>>>[FeC2O4]+ + C2O4(2-) <--> [Fe(C2O4)2)]- pKf2 = -7.05
>>>[Fe(C2O4)2]- + C2O4(2-) <--> [Fe(C2O4)3)](3-) pKf3 = -5.41
>>>(So total pKf = 20.00.)
>>>Citrate:
>>>Fe(3+) + Cit(3-) <--> [FeCit](aq) pKf = -11.8
>>>Redox:
>>>Fe(3+) + e- <--> Fe(2+) Eo = 0.771 V
>>>SO4(2-) + H2O + 2e- <--> SO3(2-) + 2OH- Eo = -0.936 V
>>>(Hmm, that's in alkali.)
>>>
>>>So: Fe(OH)3 is damned insoluble; Fe(3+) is pretty acidic (as aqueous ions
>>>go); FeCl3 is somewhat more soluble, but it still takes a lot of chloride
>>>and acid to overcome the insolubility of Fe(OH)3; chelates like EDTA, et
>>>al., oxalate, citrate, etc. grab on real tight, solvating iron well; and a
>>>variety of reducing agents will suffice, but only if you get the iron into
>>>solution to react with it.
>>>
>>>Tim
>>
>>I don't suppose that you would consider trying to analyze the impact
>>of sodium bismuthate and sodium bisulfite on the ferrous chloride /
>>ferric chloride / cuprous chloride / cupric chloride / ferric
>
>You must mean something else other than sodium bismuthate for a reducing
>agent. It's a very strong oxidizing agent. See:
>http://www.newi.ac.uk/buckleyc/titrat.htm
>
>Maybe you're thinking of something like sodium dithionite.
>
>>hydroxide solutions.
>>
>>Yes there is usually all those species and more when ferric chloride
>>is used as a copper echant.

Well how about that. I misremember ed after 30 or 40 years.

08 Mar 2008 07:36:20

The Phantom

Re: semi off-topic: how to clean ferrichloride stains

On Fri, 07 Mar 2008 02:20:24 GMT, JosephKK <quiettechblue@yahoo.com > wrote:

<SNIP >
>>You must mean something else other than sodium bismuthate for a reducing
>>agent. It's a very strong oxidizing agent. See:
>>http://www.newi.ac.uk/buckleyc/titrat.htm
>>
>>Maybe you're thinking of something like sodium dithionite.
>>
>>>hydroxide solutions.
>>>
>>>Yes there is usually all those species and more when ferric chloride
>>>is used as a copper echant.
>
>Well how about that. I misremember ed after 30 or 40 years.

You have that problem too?

I thought I remembered right, but I looked it up in my old Semimicro
Quantitative Analysis book to be sure!

Turns out sodium bismuthate is the reagent used to detect manganese. It
can oxidize maganese to permanganate ion, which is the detected by its
purple color. One normally thinks of (potassium) permanganate as a
powerful oxidizer, but bismuthate can oxidize manganese in a low oxidation
state all the way to permanganate.

08 Mar 2008 09:52:52

Tim Williams

Re: semi off-topic: how to clean ferrichloride stains

"The Phantom" <phantom@aol.com > wrote in message
news:6tb5t3d3nerp07prdr07ctkiqaf7h42gqi@4ax.com...
> Turns out sodium bismuthate is the reagent used to detect manganese. It
> can oxidize maganese to permanganate ion, which is the detected by its
> purple color. One normally thinks of (potassium) permanganate as a
> powerful oxidizer, but bismuthate can oxidize manganese in a low
oxidation
> state all the way to permanganate.

Bleach (hypochlorite) too. In fact, bleach is a suprisingly strong
oxidizer, not something you'd expect for off-the-shelf products!

Tim

--
Deep Fryer: A very philosophical monk.
Website @ http://webpages.charter.net/dawill/tmoranwms

08 Mar 2008 15:02:28

The Phantom

Re: semi off-topic: how to clean ferrichloride stains

On Sat, 8 Mar 2008 09:52:52 -0600, "Tim Williams" <tmoranwms@gmail.com >
wrote:

>"The Phantom" <phantom@aol.com> wrote in message
>news:6tb5t3d3nerp07prdr07ctkiqaf7h42gqi@4ax.com...
>> Turns out sodium bismuthate is the reagent used to detect manganese. It
>> can oxidize maganese to permanganate ion, which is the detected by its
>> purple color. One normally thinks of (potassium) permanganate as a
>> powerful oxidizer, but bismuthate can oxidize manganese in a low
>oxidation
>> state all the way to permanganate.
>
>Bleach (hypochlorite) too. In fact, bleach is a suprisingly strong
>oxidizer, not something you'd expect for off-the-shelf products!

Are you saying that hypochlorite can oxidize manganous to permanganate?

I gave it a try, and under both alkaline and acidic conditions I didn't see
any purple color (using Clorox for the hypochlorite). But I did get a
definite purple with bismuthate. Is some special condition needed?

By the way, have you noticed that Clorox currently on the store shelves is
6.00%, but I'm sure it used to be 5.25%? Is this a comment on the state of
our culture? Things are dirtier now, and need a more powerful bleach?

And, speaking of products available off-the-shelf--hydrogen peroxide in the
35% food grade concentration. That stuff is dangerous.

Furthermore, I noticed that Home Depot is selling gallon jugs of
concentrated sulfuric acid as a drain opener!

08 Mar 2008 16:14:26

Jim Thompson

Re: semi off-topic: how to clean ferrichloride stains

On Sat, 08 Mar 2008 15:02:28 -0800, The Phantom <phantom@aol.com >
wrote:

>On Sat, 8 Mar 2008 09:52:52 -0600, "Tim Williams" <tmoranwms@gmail.com>
>wrote:
>
>>"The Phantom" <phantom@aol.com> wrote in message
>>news:6tb5t3d3nerp07prdr07ctkiqaf7h42gqi@4ax.com...
>>> Turns out sodium bismuthate is the reagent used to detect manganese. It
>>> can oxidize maganese to permanganate ion, which is the detected by its
>>> purple color. One normally thinks of (potassium) permanganate as a
>>> powerful oxidizer, but bismuthate can oxidize manganese in a low
>>oxidation
>>> state all the way to permanganate.
>>
>>Bleach (hypochlorite) too. In fact, bleach is a suprisingly strong
>>oxidizer, not something you'd expect for off-the-shelf products!
>
>Are you saying that hypochlorite can oxidize manganous to permanganate?
>
>I gave it a try, and under both alkaline and acidic conditions I didn't see
>any purple color (using Clorox for the hypochlorite). But I did get a
>definite purple with bismuthate. Is some special condition needed?
>
>By the way, have you noticed that Clorox currently on the store shelves is
>6.00%, but I'm sure it used to be 5.25%? Is this a comment on the state of
>our culture? Things are dirtier now, and need a more powerful bleach?
>
>And, speaking of products available off-the-shelf--hydrogen peroxide in the
>35% food grade concentration. That stuff is dangerous.
>
>Furthermore, I noticed that Home Depot is selling gallon jugs of
>concentrated sulfuric acid as a drain opener!

Ha! Just look at Ace Hardware for all the interesting things you can
buy by the gallon ;-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice:(480)460-2350 | |
| E-mail Address at Website Fax:(480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

America: Land of the Free, Because of the Brave

09 Mar 2008 00:21:16

Tim Williams

Re: semi\\Fully off-topic: chemistry

"The Phantom" <phantom@aol.com > wrote in message
news:0a66t3ld3p2p6ugpgn7od8isrm84aev7us@4ax.com...
> Are you saying that hypochlorite can oxidize manganous to permanganate?
>
> I gave it a try, and under both alkaline and acidic conditions I didn't
see
> any purple color (using Clorox for the hypochlorite). But I did get a
> definite purple with bismuthate. Is some special condition needed?

Alkaline should do it; manganate (rather than permanganate) may be
necessary (i.e. hell ass damn alkaline). Yields suck nard, but it can turn
color.

> By the way, have you noticed that Clorox currently on the store shelves
is
> 6.00%, but I'm sure it used to be 5.25%? Is this a comment on the state
of
> our culture? Things are dirtier now, and need a more powerful bleach?

Heh...who knows.

> And, speaking of products available off-the-shelf--hydrogen peroxide in
the
> 35% food grade concentration. That stuff is dangerous.

I haven't seen it around, just at random anyway. Another excellent
oxidizer for sure, and good for some coordination chemistry (blue
peroxychromate, red peroxytitanate, etc.).

> Furthermore, I noticed that Home Depot is selling gallon jugs of
> concentrated sulfuric acid as a drain opener!

I get the red bottle stuff, Liquid Fire, from Ace Hardware. I think they
recently reformulated; the stuff I bought last month came sealed in a
plastic bag (heh, I wonder if they were having too many accidents..) and is
darker in color. I don't have large enough Pyrex glassware (..or balls..)
to boil it out, so I use it as-is. Still works fine.

Tim

--
Deep Fryer: A very philosophical monk.
Website @ http://webpages.charter.net/dawill/tmoranwms

09 Mar 2008 16:30:38

JosephKK

Re: semi off-topic: how to clean ferrichloride stains

On Sat, 08 Mar 2008 07:36:20 -0800, The Phantom <phantom@aol.com >
wrote:

>On Fri, 07 Mar 2008 02:20:24 GMT, JosephKK <quiettechblue@yahoo.com> wrote:
>
><SNIP>
>>>You must mean something else other than sodium bismuthate for a reducing
>>>agent. It's a very strong oxidizing agent. See:
>>>http://www.newi.ac.uk/buckleyc/titrat.htm
>>>
>>>Maybe you're thinking of something like sodium dithionite.
>>>
>>>>hydroxide solutions.
>>>>
>>>>Yes there is usually all those species and more when ferric chloride
>>>>is used as a copper echant.
>>
>>Well how about that. I misremember ed after 30 or 40 years.
>
>You have that problem too?

I have started noticing recently.

>
>I thought I remembered right, but I looked it up in my old Semimicro
>Quantitative Analysis book to be sure!
>
>Turns out sodium bismuthate is the reagent used to detect manganese. It
>can oxidize maganese to permanganate ion, which is the detected by its
>purple color. One normally thinks of (potassium) permanganate as a
>powerful oxidizer, but bismuthate can oxidize manganese in a low oxidation
>state all the way to permanganate.

Oh, Yeah. That is one powerful oxidizer. In pure form it is a bit
yellowish as well.