Discussion:
How to dissolve powdered ruthenium metal in aqueous solvent?
(too old to reply)
Wilco Oelen
2005-04-27 13:29:39 UTC
Permalink
Hello,

I tried to dissolve some grey, finely divided powdered ruthenium metal.
According to many sites, the metal is oxidized explosively by an acidic
solution with chlorate added. Some examples of such sites:

http://www.lenntech.com/Periodic-chart-elements/Ru-en.htm
http://www.webelements.com/webelements/scholar/elements/ruthenium/key.html

I carefully tried adding KClO3 and NaClO3 to concentrated HCl, 30%
H2SO4 and aqua regia. With HCl and aqua regia this results in formation
of chlorine and deep yellow chlorine dioxide (which scared me somewhat
because of its explosive nature), but not the smallest amount of the
metal dissolves. I even had the courage to heat the solutions by
placing the test tube in a small pot with hot water, but even that did
not result in dissolving the metal.

I'm stuck with it now. Why do so many sites mention this as a method of
dissolving ruthenium? What am I doing wrong? Does anyone know an
aqueous method for dissolving the metal, without the need to use molten
alkalies and molten oxidizers?

Thanks,

Wilco
hanson
2005-04-27 14:58:40 UTC
Permalink
Post by Wilco Oelen
I tried to dissolve some grey, finely divided powdered ruthenium metal.
According to many sites, the metal is oxidized explosively by an acidic
http://www.lenntech.com/Periodic-chart-elements/Ru-en.htm
http://www.webelements.com/webelements/scholar/elements/ruthenium/key.html
I carefully tried adding KClO3 and NaClO3 to concentrated HCl,
30% H2SO4 and aqua regia. With HCl and aqua regia this
results in formation of chlorine and
deep yellow chlorine dioxide [ClO2]
(which scared me somewhat because of its explosive nature),
[hanson]
Oelen, while I have your attention... ahahahaha...
You should really be advised that you are an enviro wuss in
your dark-room hoelen, Oelen, because if ClO2 were that
"explosive" then
a) the green shits from EPA would NOT have used ClO2 in
massive quantities to disinfect the Senate buildings after the
Anthrax scare, and
b) if ClO2 were explosive then it would not be used routinely in
the paper industry for pulp bleaching ... for the last 70 years.
[Oelen]
Post by Wilco Oelen
but not the smallest amount of the metal dissolves.
I even had the courage to heat the solutions by placing the
test tube in a small pot with hot water, but even that did
not result in dissolving the metal.
I'm stuck with it now. Why do so many sites mention this as a method of
dissolving ruthenium? What am I doing wrong? Does anyone know an
aqueous method for dissolving the metal, without the need to use molten
alkalies and molten oxidizers?
Wilco
[hanson]
BTW, your website refs do not say that ClO2 is explosive, but
that upon KClO3 addition, the Ru dissolution, the dissolving reaction,
may be very rapid --> "explosive". So, first of all IF you have really
Ru, then just add the powder in VERY small doses to the solution.
Secondly, Oelen, you did something wrong because this dissolving
operation is done in industry routinely, under ambient conditions.
Give it another try, Oelen.
Remember, Oelen, Enjoy Chemistry... BUT FUCK ENVIROS
ahahaha... ahahahanson
Marvin
2005-04-27 16:12:05 UTC
Permalink
Post by Wilco Oelen
Hello,
I tried to dissolve some grey, finely divided powdered ruthenium metal.
According to many sites, the metal is oxidized explosively by an acidic
http://www.lenntech.com/Periodic-chart-elements/Ru-en.htm
http://www.webelements.com/webelements/scholar/elements/ruthenium/key.html
I carefully tried adding KClO3 and NaClO3 to concentrated HCl, 30%
H2SO4 and aqua regia. With HCl and aqua regia this results in formation
of chlorine and deep yellow chlorine dioxide (which scared me somewhat
because of its explosive nature), but not the smallest amount of the
metal dissolves. I even had the courage to heat the solutions by
placing the test tube in a small pot with hot water, but even that did
not result in dissolving the metal.
I'm stuck with it now. Why do so many sites mention this as a method of
dissolving ruthenium? What am I doing wrong? Does anyone know an
aqueous method for dissolving the metal, without the need to use molten
alkalies and molten oxidizers?
Thanks,
Wilco
The powdered metla is probably coated with the oxide, or even completely converted to
oxide. Look up a way to dissolve the oxide.
Wilco Oelen
2005-04-27 17:59:04 UTC
Permalink
Post by Marvin
Post by Wilco Oelen
Hello,
I tried to dissolve some grey, finely divided powdered ruthenium metal.
According to many sites, the metal is oxidized explosively by an acidic
http://www.lenntech.com/Periodic-chart-elements/Ru-en.htm
http://www.webelements.com/webelements/scholar/elements/ruthenium/key.html
Post by Marvin
Post by Wilco Oelen
I carefully tried adding KClO3 and NaClO3 to concentrated HCl, 30%
H2SO4 and aqua regia. With HCl and aqua regia this results in formation
of chlorine and deep yellow chlorine dioxide (which scared me somewhat
because of its explosive nature), but not the smallest amount of the
metal dissolves. I even had the courage to heat the solutions by
placing the test tube in a small pot with hot water, but even that did
not result in dissolving the metal.
I'm stuck with it now. Why do so many sites mention this as a method of
dissolving ruthenium? What am I doing wrong? Does anyone know an
aqueous method for dissolving the metal, without the need to use molten
alkalies and molten oxidizers?
Thanks,
Wilco
The powdered metla is probably coated with the oxide, or even
completely converted to
Post by Marvin
oxide. Look up a way to dissolve the oxide.
No, I don't think so. It was sold to me as 99.96+ ruthenium metal.
There may be some oxide in it, but completely converted to oxide seems
very unrealistic to me, the more because the metal is very unreactive.

Wilco
Marvin
2005-04-28 17:45:38 UTC
Permalink
Post by Wilco Oelen
Post by Marvin
Post by Wilco Oelen
Hello,
I tried to dissolve some grey, finely divided powdered ruthenium
metal.
Post by Marvin
Post by Wilco Oelen
According to many sites, the metal is oxidized explosively by an
acidic
Post by Marvin
Post by Wilco Oelen
http://www.lenntech.com/Periodic-chart-elements/Ru-en.htm
http://www.webelements.com/webelements/scholar/elements/ruthenium/key.html
Post by Marvin
Post by Wilco Oelen
I carefully tried adding KClO3 and NaClO3 to concentrated HCl, 30%
H2SO4 and aqua regia. With HCl and aqua regia this results in
formation
Post by Marvin
Post by Wilco Oelen
of chlorine and deep yellow chlorine dioxide (which scared me
somewhat
Post by Marvin
Post by Wilco Oelen
because of its explosive nature), but not the smallest amount of
the
Post by Marvin
Post by Wilco Oelen
metal dissolves. I even had the courage to heat the solutions by
placing the test tube in a small pot with hot water, but even that
did
Post by Marvin
Post by Wilco Oelen
not result in dissolving the metal.
I'm stuck with it now. Why do so many sites mention this as a
method of
Post by Marvin
Post by Wilco Oelen
dissolving ruthenium? What am I doing wrong? Does anyone know an
aqueous method for dissolving the metal, without the need to use
molten
Post by Marvin
Post by Wilco Oelen
alkalies and molten oxidizers?
Thanks,
Wilco
The powdered metla is probably coated with the oxide, or even
completely converted to
Post by Marvin
oxide. Look up a way to dissolve the oxide.
No, I don't think so. It was sold to me as 99.96+ ruthenium metal.
There may be some oxide in it, but completely converted to oxide seems
very unrealistic to me, the more because the metal is very unreactive.
Wilco
I agree that it is unlikely to be completely oxidized, but it is not unlikely to have an
oxide coating on every particle. Some metals get unreactive because of an oxide coating.
A fine powder has a very large surface area per gram.
Wilco Oelen
2005-04-28 18:29:27 UTC
Permalink
Post by Marvin
Post by Wilco Oelen
Post by Marvin
Post by Wilco Oelen
Hello,
I tried to dissolve some grey, finely divided powdered ruthenium
metal.
Post by Marvin
Post by Wilco Oelen
According to many sites, the metal is oxidized explosively by an
acidic
Post by Marvin
Post by Wilco Oelen
http://www.lenntech.com/Periodic-chart-elements/Ru-en.htm
http://www.webelements.com/webelements/scholar/elements/ruthenium/key.html
Post by Marvin
Post by Wilco Oelen
Post by Marvin
Post by Wilco Oelen
I carefully tried adding KClO3 and NaClO3 to concentrated HCl, 30%
H2SO4 and aqua regia. With HCl and aqua regia this results in
formation
Post by Marvin
Post by Wilco Oelen
of chlorine and deep yellow chlorine dioxide (which scared me
somewhat
Post by Marvin
Post by Wilco Oelen
because of its explosive nature), but not the smallest amount of
the
Post by Marvin
Post by Wilco Oelen
metal dissolves. I even had the courage to heat the solutions by
placing the test tube in a small pot with hot water, but even that
did
Post by Marvin
Post by Wilco Oelen
not result in dissolving the metal.
I'm stuck with it now. Why do so many sites mention this as a
method of
Post by Marvin
Post by Wilco Oelen
dissolving ruthenium? What am I doing wrong? Does anyone know an
aqueous method for dissolving the metal, without the need to use
molten
Post by Marvin
Post by Wilco Oelen
alkalies and molten oxidizers?
Thanks,
Wilco
The powdered metla is probably coated with the oxide, or even
completely converted to
Post by Marvin
oxide. Look up a way to dissolve the oxide.
No, I don't think so. It was sold to me as 99.96+ ruthenium metal.
There may be some oxide in it, but completely converted to oxide seems
very unrealistic to me, the more because the metal is very
unreactive.
Post by Marvin
Post by Wilco Oelen
Wilco
I agree that it is unlikely to be completely oxidized, but it is not unlikely to have an
oxide coating on every particle. Some metals get unreactive because of an oxide coating.
A fine powder has a very large surface area per gram.
I know of the phenomenon. Aluminium, and also titanium have this effect
and certain metals also become passivated, when they are treated with
dichromate/nitric acid.

However, ruthenium is one of the platinum metals and I have not read
anything about an oxide coating. In air, this metal can be oxidized
*very* slowly, but then the tetroxide RuO4 is formed. RuO4 is a very
volatile compound, melting just below 30 C and boiling at just over 100
C. It quickly evaporates.

Wilco
Farooq W
2005-04-27 16:27:16 UTC
Permalink
Post by Wilco Oelen
Hello,
I tried to dissolve some grey, finely divided powdered ruthenium metal.
According to many sites, the metal is oxidized explosively by an acidic
http://www.lenntech.com/Periodic-chart-elements/Ru-en.htm
http://www.webelements.com/webelements/scholar/elements/ruthenium/key.html
Post by Wilco Oelen
I carefully tried adding KClO3 and NaClO3 to concentrated HCl, 30%
H2SO4 and aqua regia. With HCl and aqua regia this results in
formation
Post by Wilco Oelen
of chlorine and deep yellow chlorine dioxide (which scared me
somewhat
Post by Wilco Oelen
because of its explosive nature), but not the smallest amount of the
metal dissolves. I even had the courage to heat the solutions by
placing the test tube in a small pot with hot water, but even that did
not result in dissolving the metal.
I'm stuck with it now. Why do so many sites mention this as a method of
dissolving ruthenium? What am I doing wrong? Does anyone know an
aqueous method for dissolving the metal, without the need to use molten
alkalies and molten oxidizers?
Thanks,
Wilco
My old _Applied Inorganic Analysis_ by Hildebrand has it. You can try
this one too and se how successful is this experiment.
He writes " Ruthenium and osmium are dissolved by alkali hypochlorite
solutions. Howe and Mercer (Ref.) advocated this method of attack for
metallic powders conatining ruthenium. The solution must contain free
alkali in order to avoid oxidizing the metal to the volatile
tetraoxide. Nearly pure ruthenium is rapidly dissolved."

Ref: Howe and Mercer, J.Am. Chem. Soc., Year 1925, Vol. 47, page 2926

One can not believe that JACS used to used to publish inorganics too,
now it seems like a biochemistry/organic chemistry journal.
Uncle Al
2005-04-27 17:31:49 UTC
Permalink
Post by Wilco Oelen
Post by Wilco Oelen
Hello,
I tried to dissolve some grey, finely divided powdered ruthenium
metal.
Post by Wilco Oelen
According to many sites, the metal is oxidized explosively by an
acidic
Post by Wilco Oelen
http://www.lenntech.com/Periodic-chart-elements/Ru-en.htm
http://www.webelements.com/webelements/scholar/elements/ruthenium/key.html
Post by Wilco Oelen
I carefully tried adding KClO3 and NaClO3 to concentrated HCl, 30%
H2SO4 and aqua regia. With HCl and aqua regia this results in
formation
Post by Wilco Oelen
of chlorine and deep yellow chlorine dioxide (which scared me
somewhat
Post by Wilco Oelen
because of its explosive nature), but not the smallest amount of the
metal dissolves. I even had the courage to heat the solutions by
placing the test tube in a small pot with hot water, but even that
did
Post by Wilco Oelen
not result in dissolving the metal.
I'm stuck with it now. Why do so many sites mention this as a method
of
Post by Wilco Oelen
dissolving ruthenium? What am I doing wrong? Does anyone know an
aqueous method for dissolving the metal, without the need to use
molten
Post by Wilco Oelen
alkalies and molten oxidizers?
Thanks,
Wilco
My old _Applied Inorganic Analysis_ by Hildebrand has it. You can try
this one too and se how successful is this experiment.
He writes " Ruthenium and osmium are dissolved by alkali hypochlorite
solutions. Howe and Mercer (Ref.) advocated this method of attack for
metallic powders conatining ruthenium. The solution must contain free
alkali in order to avoid oxidizing the metal to the volatile
tetraoxide. Nearly pure ruthenium is rapidly dissolved."
Ref: Howe and Mercer, J.Am. Chem. Soc., Year 1925, Vol. 47, page 2926
One can not believe that JACS used to used to publish inorganics too,
now it seems like a biochemistry/organic chemistry journal.
RuO2 is tremendously hazardous. It is volatile, it will go after your
corneas, and it eats Teflon. Great "chemical ozonolysis" reagent. Be
very serious when pontentially near it.
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf
Wilco Oelen
2005-04-27 18:01:07 UTC
Permalink
I know of the dangers of ruthenium oxide. It is the tetroxide ReO4
which is very dangerous, the oxide ReO2 is relatively benign. But,
sure, I'll be very careful with the ruthenium, also because of the
volatility of RuO4 (it boils at just over 100 C).

Thanks,

Wilco
Farooq W
2005-04-27 18:33:01 UTC
Permalink
Post by Uncle Al
Post by Wilco Oelen
Post by Wilco Oelen
Post by Wilco Oelen
I'm stuck with it now. Why do so many sites mention this as a method
of
Post by Wilco Oelen
dissolving ruthenium? What am I doing wrong? Does anyone know an
aqueous method for dissolving the metal, without the need to use
molten
Post by Wilco Oelen
alkalies and molten oxidizers?
Thanks,
Wilco
My old _Applied Inorganic Analysis_ by Hildebrand has it. You can try
this one too and se how successful is this experiment.
He writes " Ruthenium and osmium are dissolved by alkali
hypochlorite
Post by Uncle Al
Post by Wilco Oelen
solutions. Howe and Mercer (Ref.) advocated this method of attack for
metallic powders conatining ruthenium. The solution must contain free
alkali in order to avoid oxidizing the metal to the volatile
tetraoxide. Nearly pure ruthenium is rapidly dissolved."
Ref: Howe and Mercer, J.Am. Chem. Soc., Year 1925, Vol. 47, page 2926
One can not believe that JACS used to used to publish inorganics too,
now it seems like a biochemistry/organic chemistry journal.
RuO2 is tremendously hazardous. It is volatile, it will go after your
corneas, and it eats Teflon. Great "chemical ozonolysis" reagent.
Be
Post by Uncle Al
very serious when pontentially near it.
I had heard of OsO4 destroying corneas permenantly, is ruthenium
tetraoxide severely corrosive too? BTW, RuO2 appears to be a solid, is
that toxic?
Uncle Al
2005-04-27 20:16:07 UTC
Permalink
Post by Wilco Oelen
Post by Uncle Al
Post by Wilco Oelen
Post by Wilco Oelen
Post by Wilco Oelen
I'm stuck with it now. Why do so many sites mention this as a
method
Post by Uncle Al
Post by Wilco Oelen
of
Post by Wilco Oelen
dissolving ruthenium? What am I doing wrong? Does anyone know an
aqueous method for dissolving the metal, without the need to use
molten
Post by Wilco Oelen
alkalies and molten oxidizers?
Thanks,
Wilco
My old _Applied Inorganic Analysis_ by Hildebrand has it. You can
try
Post by Uncle Al
Post by Wilco Oelen
this one too and se how successful is this experiment.
He writes " Ruthenium and osmium are dissolved by alkali
hypochlorite
Post by Uncle Al
Post by Wilco Oelen
solutions. Howe and Mercer (Ref.) advocated this method of attack
for
Post by Uncle Al
Post by Wilco Oelen
metallic powders conatining ruthenium. The solution must contain
free
Post by Uncle Al
Post by Wilco Oelen
alkali in order to avoid oxidizing the metal to the volatile
tetraoxide. Nearly pure ruthenium is rapidly dissolved."
Ref: Howe and Mercer, J.Am. Chem. Soc., Year 1925, Vol. 47, page
2926
Post by Uncle Al
Post by Wilco Oelen
One can not believe that JACS used to used to publish inorganics
too,
Post by Uncle Al
Post by Wilco Oelen
now it seems like a biochemistry/organic chemistry journal.
RuO2 is tremendously hazardous. It is volatile, it will go after
your
Post by Uncle Al
corneas, and it eats Teflon. Great "chemical ozonolysis" reagent.
Be
Post by Uncle Al
very serious when pontentially near it.
I had heard of OsO4 destroying corneas permenantly, is ruthenium
tetraoxide severely corrosive too? BTW, RuO2 appears to be a solid, is
that toxic?
Make that RuO4 as the hazard. Hydrated RuO2 is the starting material,
then into periodate slurry to oxidize it up. I made one of the
intermediates on the way to peristylane, the 1,3-diketone. A teflon
stirrer paddle went in. What came out look like charcoal. Good
chemistry, nasty reagent.

Ceramic RuO2 as opposed to the hydrated stuff can be remarkably inert.
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf
Wilco Oelen
2005-04-27 18:13:15 UTC
Permalink
Farooq,

Thanks, I'll give it a try and let you know.

I hope that the fellow who sold it to me has not mistakenly given me
some iridium. Iridium is VERY inert, but ruthenium is less so. The two
metal powders look very similar.

Wilco
Farooq W
2005-04-27 18:27:33 UTC
Permalink
Post by Wilco Oelen
Farooq,
Thanks, I'll give it a try and let you know.
I hope that the fellow who sold it to me has not mistakenly given me
some iridium. Iridium is VERY inert, but ruthenium is less so. The two
metal powders look very similar.
Wilco
Let know if that turns out to be iridium, that oldie most likely has
dissolution methods for iridium too. I will check that.
Wilco Oelen
2005-04-27 19:54:07 UTC
Permalink
Post by Wilco Oelen
Farooq,
Thanks, I'll give it a try and let you know.
I hope that the fellow who sold it to me has not mistakenly given me
some iridium. Iridium is VERY inert, but ruthenium is less so. The two
metal powders look very similar.
Wilco
Farooq,

The method you suggested works GREAT. I took 5 ml of bleach with 4%
active chlorine and added quite some NaOH to this, just to be sure that
no RuO4 escapes from the liquid. I dissolved the NaOH in the bleach and
then added appr. 25 mg of ruthenium metal. The metal slowly dissolves
at room temperature, but with a little heating (not boiling), the metal
was dissolved in just a few minutes.

The solution I obtain is deep orange/brown and clear. On dilution it is
bright orange. Does the old book also tell what this deep orange/brown
compound is?

While the solid dissolves, I also get a lot of oxygen. I assume that is
due to decomposition of the ClO(-) at the elevated temperatures.

If the book has info on iridium, then I also am interested in that.
Over here, I have a supply of powdered rhenium and the powdered
platinum metals (except osmium) at low cost.

What surprises me is that the method, mentioned in the websites of my
initial post does not work. I even had such a solution with NaClO3 and
HCl/HNO3 overnight, but not any of the metal dissolved in it. I only
got Cl2 (smell) and ClO2 (looks nice, the gas has a really intense
bright yellow color). Would these sites be totally wrong? It might be
that one site gives wrong info and that others are mimicking it. My
books do not mention this method. They only mention melting NaOH+KNO3
and adding the metal to this melt.


As far as toxicity of RuO4 is concerned, this also is quite toxic, but
not as powerful as OsO4. In my old German books I read that OsO4 reacts
with organic tissue, forming micro-crystals of metallic osmium. As the
book explains, these micro-crystals irritate surrounding tissue like
hell by abrasion and when the eye becomes contaminated with these small
crystals of osmium, then the irritation may become so severe that the
eye is damaged permanently.

Wilco
Farooq W
2005-04-28 13:28:40 UTC
Permalink
Post by Wilco Oelen
Post by Wilco Oelen
Farooq,
Thanks, I'll give it a try and let you know.
I hope that the fellow who sold it to me has not mistakenly given me
some iridium. Iridium is VERY inert, but ruthenium is less so. The
two
Post by Wilco Oelen
metal powders look very similar.
Wilco
Farooq,
The method you suggested works GREAT.
Good.
Post by Wilco Oelen
I took 5 ml of bleach with 4%
active chlorine and added quite some NaOH to this, just to be sure that
no RuO4 escapes from the liquid. I dissolved the NaOH in the bleach and
then added appr. 25 mg of ruthenium metal. The metal slowly dissolves
at room temperature, but with a little heating (not boiling), the metal
was dissolved in just a few minutes.
The solution I obtain is deep orange/brown and clear. On dilution it is
bright orange. Does the old book also tell what this deep
orange/brown
Post by Wilco Oelen
compound is?
Actually this book is of analytical chemistry and practically
descriptive on material and methods side. No mention is made of the
reaction that causes its rapid dissolution. You can ask someone here in
sci.chem to send that JACS reference to you which I earlier posted to
you, where you might find the details.
Post by Wilco Oelen
While the solid dissolves, I also get a lot of oxygen. I assume that is
due to decomposition of the ClO(-) at the elevated temperatures.
If the book has info on iridium, then I also am interested in that.
Is that urgent?
Post by Wilco Oelen
Over here, I have a supply of powdered rhenium and the powdered
platinum metals (except osmium) at low cost.
What surprises me is that the method, mentioned in the websites of my
initial post does not work. I even had such a solution with NaClO3 and
HCl/HNO3 overnight, but not any of the metal dissolved in it. I only
got Cl2 (smell) and ClO2 (looks nice, the gas has a really intense
bright yellow color). Would these sites be totally wrong? It might be
that one site gives wrong info and that others are mimicking it. My
books do not mention this method. They only mention melting NaOH+KNO3
and adding the metal to this melt.
Hildebrand does mention dissolving ruthenium in HCl solutions with
oxidizing agents but KClO3 ia not mentioned.
Post by Wilco Oelen
As far as toxicity of RuO4 is concerned, this also is quite toxic, but
not as powerful as OsO4. In my old German books I read that OsO4 reacts
with organic tissue, forming micro-crystals of metallic osmium. As the
book explains, these micro-crystals irritate surrounding tissue like
hell by abrasion and when the eye becomes contaminated with these small
crystals of osmium, then the irritation may become so severe that the
eye is damaged permanently.
Wilco
Wilco Oelen
2005-04-28 18:35:07 UTC
Permalink
Farooq,

It is a pity that the book does not contain any chemical equations
about the compounds formed, but anyway, it helped a lot.

Looking up the info for iridium is not urgent. Please do not go to the
library especially for this. If you happen to be there and have some
time left, then of course I would be pleased if you take the time for
it.

By the way, I left the solution with ruthenium standing for one day,
stoppered, so that no fresh air can enter the test tube. The color has
changed from orange/brown to really deep bright red. It is not like
ferric+thiocyanate, it is a very bright and saturated color. I'll try
to find out what this compound might be.

Wilco
Farooq W
2005-04-29 01:59:26 UTC
Permalink
Post by Wilco Oelen
Farooq,
It is a pity that the book does not contain any chemical equations
about the compounds formed, but anyway, it helped a lot.
Looking up the info for iridium is not urgent. Please do not go to the
library especially for this. If you happen to be there and have some
time left, then of course I would be pleased if you take the time for
it.
By the way, I left the solution with ruthenium standing for one day,
stoppered, so that no fresh air can enter the test tube. The color has
changed from orange/brown to really deep bright red. It is not like
ferric+thiocyanate, it is a very bright and saturated color. I'll try
to find out what this compound might be.
Wilco
You can post a request in sci.chem to send the follwing article to you.
Howe and Mercer, J.Am. Chem. Soc., Year 1925, Vol. 47, page 2926.
Wilco Oelen
2005-04-29 11:51:10 UTC
Permalink
Post by Farooq W
Post by Wilco Oelen
Farooq,
It is a pity that the book does not contain any chemical equations
about the compounds formed, but anyway, it helped a lot.
Looking up the info for iridium is not urgent. Please do not go to
the
Post by Wilco Oelen
library especially for this. If you happen to be there and have some
time left, then of course I would be pleased if you take the time for
it.
By the way, I left the solution with ruthenium standing for one day,
stoppered, so that no fresh air can enter the test tube. The color
has
Post by Wilco Oelen
changed from orange/brown to really deep bright red. It is not like
ferric+thiocyanate, it is a very bright and saturated color. I'll try
to find out what this compound might be.
Wilco
You can post a request in sci.chem to send the follwing article to you.
Howe and Mercer, J.Am. Chem. Soc., Year 1925, Vol. 47, page 2926.
I already found out. The bright red color is due to formation of
ruthenate ion, RuO4(2-). At lower concentration this ion is bright
orange. It is the most stable in strong alkalies.

Initially, the more sepia-like brown color is due to a mix of green
perruthenate, RuO4(-) and red/orange ruthenate.

Perruthenate, however, is not very stable in strong alkalies. It is
reduced slowly, giving oxygen and red ruthenate. This explains why the
solution has become much brighter red on standing.

Wilco
muha
2005-04-27 23:09:15 UTC
Permalink
my book says that Ru reacts with NaClO bleach at room temp.
Tony Lam
2005-05-02 12:42:51 UTC
Permalink
Post by Wilco Oelen
Hello,
I tried to dissolve some grey, finely divided powdered ruthenium metal.
According to many sites, the metal is oxidized explosively by an acidic
http://www.lenntech.com/Periodic-chart-elements/Ru-en.htm
http://www.webelements.com/webelements/scholar/elements/ruthenium/key.html
I carefully tried adding KClO3 and NaClO3 to concentrated HCl, 30%
H2SO4 and aqua regia. With HCl and aqua regia this results in formation
of chlorine and deep yellow chlorine dioxide (which scared me somewhat
because of its explosive nature), but not the smallest amount of the
metal dissolves. I even had the courage to heat the solutions by
placing the test tube in a small pot with hot water, but even that did
not result in dissolving the metal.
I'm stuck with it now. Why do so many sites mention this as a method of
dissolving ruthenium? What am I doing wrong? Does anyone know an
aqueous method for dissolving the metal, without the need to use molten
alkalies and molten oxidizers?
Thanks,
Wilco
What oxidation states of Ru needed?? Oxidizing Ru(III) metal by air to
RuO2, then oxidize by ClO4- is a good way for Ru(IV) to Ru (VIII)
chemistry. For Ru(II) , starts with Ru (III) then reduce with Zn. Ru
(0), and Ru (III), just buy Ru metal or RuCl3 (netural). Ru metal do
not dissolve without changing oxidation state. I don't know the
colour of Ru(I)aqua ethier. (although some Ru (I) compound is
black/grey)

I think Ru "likes" Cl very much... one way to
replace/displace/eliminate Ru-Cl is by Ru=O... Ru-Cl bondings give
rise to huge number of strange Ru chemistry.... that on one hand is
new discovery / development, on the other hand it ruins reactions....
(especially in high oxidation state Ru chemistry)
Wilco Oelen
2005-05-02 18:00:12 UTC
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Post by Tony Lam
Post by Wilco Oelen
Hello,
I tried to dissolve some grey, finely divided powdered ruthenium metal.
According to many sites, the metal is oxidized explosively by an acidic
http://www.lenntech.com/Periodic-chart-elements/Ru-en.htm
http://www.webelements.com/webelements/scholar/elements/ruthenium/key.html
Post by Tony Lam
Post by Wilco Oelen
I carefully tried adding KClO3 and NaClO3 to concentrated HCl, 30%
H2SO4 and aqua regia. With HCl and aqua regia this results in formation
of chlorine and deep yellow chlorine dioxide (which scared me somewhat
because of its explosive nature), but not the smallest amount of the
metal dissolves. I even had the courage to heat the solutions by
placing the test tube in a small pot with hot water, but even that did
not result in dissolving the metal.
I'm stuck with it now. Why do so many sites mention this as a method of
dissolving ruthenium? What am I doing wrong? Does anyone know an
aqueous method for dissolving the metal, without the need to use molten
alkalies and molten oxidizers?
Thanks,
Wilco
What oxidation states of Ru needed??
I just need a solution in water. This can serve as a basis for further
experimenting. The method, proposed by Farooq with NaOH/NaClO works
very well. It gives Ru(VI) and Ru(VII) in strongly alkaline media.
Post by Tony Lam
Oxidizing Ru(III) metal by air to
RuO2, then oxidize by ClO4- is a good way for Ru(IV) to Ru (VIII)
What do you mean with "Ru(III) metal"? Ru(III) is not a metal, the
metal has oxidation state 0. Ru(III) indeed is oxidized by air in
alkaline environments to dark blue/black RuO2.
Post by Tony Lam
chemistry. For Ru(II) , starts with Ru (III) then reduce with Zn.
Ru
Post by Tony Lam
(0), and Ru (III), just buy Ru metal or RuCl3 (netural). Ru metal do
not dissolve without changing oxidation state.
With "dissolve" I did not mean the physical act of dissolving, but also
changing it chemically.
Post by Tony Lam
I don't know the
colour of Ru(I)aqua ethier. (although some Ru (I) compound is
black/grey)
Is there an aquous Ru(I) compound? As far as I know, the lowest
oxidation state in aquous compounds is +2 and this already is very
unstable. Aqueous oxidation state +2 is blue with a purple tinge and
can be made with some zinc added to an aqueous solution of ruthenium at
higher oxidation state. Water oxidizes this blue +2 to yellow/orange +3
within minutes. I know this, because I've tried this.
Post by Tony Lam
I think Ru "likes" Cl very much... one way to
replace/displace/eliminate Ru-Cl is by Ru=O... Ru-Cl bondings give
rise to huge number of strange Ru chemistry.... that on one hand is
new discovery / development, on the other hand it ruins reactions....
Yes, I noticed. Ru in its +3 and higher oxidation states apparently can
have all kinds of colors and can have quite some strange /
unpredictable reactions.
Post by Tony Lam
(especially in high oxidation state Ru chemistry)
I experimentally found out the following, starting with Ru-metal in
NaOH/NaClO:

Ru-metal dissolves in NaClO and gives deep red RuO4(2-) on standing.
This deep red compound in strongly alkaline media is easily oxidized
with some persulfate to dark green/brown RuO4(-).
With sulfite this gives dark blue/black RuO2.

When excess HCl acid is added to the deep red liquid, then the liquid
remains red, but turns somewhat more brown. Literature states that
RuO4(2-) is less stable in acid and tends to disproportionate to
RuO4(-) and Ru-compounds at lower oxidation state. So, I can explain
the change of bright red to red/brown.

On addition of zinc, the liquid first becomes bright red again.
Apparently the Ru in higher oxidation state is reduced again. The color
next shifts to yellow/orange. I assume that is Ru(III). Next, the color
shifts to blue purple. This is Ru(II). When the zinc is used up, then
the blue liquid becomes yellow/orange again in just a few minutes, even
without shaking. Not only at the surface, but uniformly over the entire
liquid.

After some time, the experimental results become very vague. I can get
any color at any oxidation state it seems. Light yellow with
persulfate, but also yellow with sulfite. Grey, but clear at oxidation
state +4 (dissolving RuO2 in dil. HCl). I simply don't understand all
of it. So you're right that with chloride, the chemistry is very
complicated. Unfortunately the dissolving method of Farooq gives
solutions with a lot of chloride in it, so testing without chloride is
not easy for me.

Wilco

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