vano
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Easiest way to make red selenium
Hi. I made red selenium very easily. I used only dilute selenous acid solution and potassium metabisulfite. I mixed solutions and put it in the
sunlight. I think 8 hours is enough to used all selenous acid, because when i added carbonate nothing happened.
I think some of you will use it because metabisulfite is much cheaper than concentrated sulfuric acid and also affordable. Selenium had nice red
colour, but i made it few days ago, since then it has been exposed to sunlight and It therefore has a dark color.
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woelen
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I know of this precedure. You can speed up the procedure by adding some chloride (e.g. dilute HCl). The chloride ions have a catalytic effect on this
reaction.
I have made some of this red Se, cleaned it with distilled water, and dried it. The dry material I put in an ampoule. But unfortunately, the material
is not stable. Over the weeks, the material turns dark grey and half a year later, you hardly can see the red color anymore. The saturation of the
color decreases over time, just to be left with zero saturation, being a dull gray material.
I have seen samples of red selenium for sale, not the amorphous material, made from reduction of a selenite or selenous oxide, but by dissolving the
thus obtained red selenium in some solvent and then very slowly letting the solvent evaporate, so that you get a crystalline solid. These crystals are
dark red and apparently they are more stable. I never purchased some of that red selenium though, because it is very expensive (several euros per
gram), and I still have severe doubts on its long-term stability. I want some for an element collection, stable for years in a display, which is in
daylight.
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unionised
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Does this procedure work with mercury?
:-)
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vano
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Quote: Originally posted by woelen  | I know of this precedure. You can speed up the procedure by adding some chloride (e.g. dilute HCl). The chloride ions have a catalytic effect on this
reaction.
I have made some of this red Se, cleaned it with distilled water, and dried it. The dry material I put in an ampoule. But unfortunately, the material
is not stable. Over the weeks, the material turns dark grey and half a year later, you hardly can see the red color anymore. The saturation of the
color decreases over time, just to be left with zero saturation, being a dull gray material.
I have seen samples of red selenium for sale, not the amorphous material, made from reduction of a selenite or selenous oxide, but by dissolving the
thus obtained red selenium in some solvent and then very slowly letting the solvent evaporate, so that you get a crystalline solid. These crystals are
dark red and apparently they are more stable. I never purchased some of that red selenium though, because it is very expensive (several euros per
gram), and I still have severe doubts on its long-term stability. I want some for an element collection, stable for years in a display, which is in
daylight. |
Can you tell me more about chlorine ion catalyst effect?
I agree, every red selenium which i made now have dark colour, but not grey, it has black colour.
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vano
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What do you mean?
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njl
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I believe unionised is referring to "red mercury" which is (as far as I know) an urban legend stemming from nuclear weapons research.
Reflux condenser?? I barely know her!
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vano
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Oh i understand. Good one 
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unionised
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| Quote: Originally posted by njl | | I believe unionised is referring to "red mercury" which is (as far as I know) an urban legend stemming from nuclear weapons research.
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:-)
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