Cu, Ni and Mn selenites + photo

I made some selenites. First one is copper selenite dihydrate CuSeO3·2H2O. It is very nice blue powder or crystal, but i never seen crystal. It's insoluble in water.

I made it from basic copper carbonate and selenous acid:

Cu2(OH)2 CO3 + 2H2SeO3 → 2CuSeO3 + ......

Second one is nickel selenite dihydrate and NiSeO3·2H2O. It's light green insoluble powder. But i think this selenite is much soluble than copper selenite, because when water added it becomes like a suspension, which is yellow liquid.

I used nickel chloride hexahydrate and sodium selenite:

NiCl2 + Na2SeO3 → NiSeO3 + 2NaCl

Third one is manganese selenite • ?H2O. Its brown insoluble solid. I do not have much information about it. It is a rather rare compound because I did not even know the color before I made it.

I used manganese carbonate and selenous acid:
MnCO3 + H2SeO3 →MnSeO3 + H2O + CO2




[Edited on 4-12-2020 by vano.kavt]

Hi and welcome to SM .

These selenites have beautiful colour, especially nickel selenite.

Colour of manganese selenite is weird for II oxidation state. It looks like some Mn(III) or Mn(IV) compound. How precipitate looked when it was freshly made? Was there red precipitate mixed with brown precipitate? Mn(II) compounds are mostly only weakly coloured. There are some exceptions like MnO or tetraamonium hexamolybdatomanganate(II), but brown colour in 99% have compounds of trivalent and tetravalent manganese.

Quote: Originally posted by Bedlasky

Hi and welcome to SM . These selenites have beautiful colour, especially nickel selenite. Colour of manganese selenite is weird for II oxidation state. It looks like some Mn(III) or Mn(IV) compound. How precipitate looked when it was freshly made? Was there red precipitate mixed with brown precipitate? Mn(II) compounds are mostly only weakly coloured. There are some exceptions like MnO or tetraamonium hexamolybdatomanganate(II), but brown colour in 99% have compounds of trivalent and tetravalent manganese.

Welcome to SM Vano! I have 2 language in common with you, except Georgian, but probably you don't know Ukrainian

Edit: sorry, I didn't realise you are talking about selenous acid not selenic acid. So, please ignore the rest of the message.

Selenic acid seems to be a more strong oxidiser than sulfuric acid, it oxidise HCl to Cl2. So, I would suppose it can oxidise Mn(II) and you get not the selenic acid salt of Mn(II) but selenous acid salt (what should be name for this?) of some higher valency of Mn. Also some irregularity in color of the Mn compounds could suggest that the oxidising is not finished completely.

[Edited on 4-12-2020 by teodor]

Quote: Originally posted by teodor

Welcome to SM Vano! I have 2 language in common with you, except Georgian, but probably you don't know Ukrainian Edit: sorry, I didn't realise you are talking about selenous acid not selenic acid. So, please ignore the rest of the message. Selenic acid seems to be a more strong oxidiser than sulfuric acid, it oxidise HCl to Cl2. So, I would suppose it can oxidise Mn(II) and you get not the selenic acid salt of Mn(II) but selenous acid salt (what should be name for this?) of some higher valency of Mn. Also some irregularity in color of the Mn compounds could suggest that the oxidising is not finished completely. [Edited on 4-12-2020 by teodor]

Quote: Originally posted by teodor

I don't have any compounds of selenium yet, but what I red and also it looks interesting, is that BaSeO4 (which is insoluble like BaSO4) on heating with HCl goes into solution as BaSeO3 (which is soluble). I remember I was searching different imaginary ways to dissolve BaSO4 also by reducing. Its interesting that is is much easier with selenate .

Thanks for posting Vano. I can tell that you and I like to do the same kind of experiments (colorful inorganic).

The selenites look very nice. I hope to try them someday.

Sodium selenite and other selenites appear to be extremely toxic. Did you take any different precautions when working with them, simply use gloves and not put it in your mouth?

Quote: Originally posted by MidLifeChemist

Thanks for posting Vano. I can tell that you and I like to do the same kind of experiments (colorful inorganic). The selenites look very nice. I hope to try them someday. Sodium selenite and other selenites appear to be extremely toxic. Did you take any different precautions when working with them, simply use gloves and not put it in your mouth?

Quote: Originally posted by vano.kavt

Thank you. Yes i know soluble selenites have very low LD. But selenite is less toxic than selenate. I read somewhere (there was no English source) that sodium selenate is three to four times more toxic than sodium cyanide.

Quote: Originally posted by MidLifeChemist

Quote: Originally posted by vano.kavt   Thank you. Yes i know soluble selenites have very low LD. But selenite is less toxic than selenate. I read somewhere (there was no English source) that sodium selenate is three to four times more toxic than sodium cyanide. I've read a few reports (all in English, lol). From what I can tell, sodium selenite has the same toxicity as sodium cyanide, and sodium selenate is three times more toxic. I would mail you cobalt salts if you were in my country, but you are quite far away.

Quote: Originally posted by teodor

Are you buying the stuff on behalf of some company? I have no idea what are regulations you have in Georgia now, but its interesting how the country goes. In Ukraine, you know, everything is possible, but you should make friend with proper people. I would be glad if conditions for amateur chemistry in Georgia, especially accruing wide range of chemicals, are good because I like your country, alas have never been there.

Quote: Originally posted by teodor

Do you use some special precautions working with fluorine compounds? It will be interesting to know a bit more about your equipment & techniques if you really have plans to go that side. There are quite different people here, with different skills, many of them (including me) are not connected professionally with chemistry, so they are amateurs studying mostly by videos, old books and info in this forum, and really many of us are not ready to work even with Se compounds. I think it is important to share techniques and how to use equipment, protection etc for benefit of others people. So, if you have some experience like safe practices it would be interesting to read. I would say more interesting than Nile Blue-Red's video about safety which nevertheless already has a lot of views and discussions here.

I rarely come in contact with fluorine compounds. Mostly I avoid inhaling. As for selenium compounds, I usually use a mask, the main thing is that the powder does not get into the body. A year ago I inhaled large amounts of sublimated selenium dioxide, though I was fine. To be honest I work with acids and alkalis without gloves. I no longer have a reaction after falling on my hands, because I use them from a young age and their properties are greatly exaggerated. I once made mercury oxide from Hg2(No3)2 •2H2O(Everyone thinks it is white solid, but it is actually yellow). When dioxide heated it prodused mercury vapour. I heated it with torch and I had mercury all over my hand after the reaction(in the photo). But it is easily removed, so if someone has a similar case, do not be afraid, the main thing is to wear a mask and glasses. I think my mistakes and experience will help everyone so I will share it with you often.

This is mercury. I saved this photo:

[Edited on 5-12-2020 by vano.kavt]



[Edited on 5-12-2020 by vano.kavt]

This is mercury(I) nitrate dihydrate.

Quote: Originally posted by vano.kavt

ITo be honest I work with acids and alkalis without gloves. I no longer have a reaction after falling on my hands, because I use them from a young age and their properties are greatly exaggerated.

Quote: Originally posted by MidLifeChemist

Thanks for sharing your experiences! When I review lists of lab accidents, most chemical injuries from spills / burns were from bromine (liquid and vapors) and concentrated nitric acid (people spilling a good amount on themselves, not just a few drops). Have you had bromine on your hands before?

Just a few drops, but the skin will not burn. For example hydrogen peroxide (50%) is poured on my hand many times, but it just whitens and disappears in a few hours, although the fingerprints look very nice

[Edited on 5-12-2020 by vano.kavt]

[Edited on 5-12-2020 by vano.kavt]

Quote: Originally posted by Antiswat

i think a lot of safety is hypocrisy, you can find video from i believe his name is Nile Red on youtube where he pours various acids on his hands and even concentrated sulfuric acid started having an effect after around a minute

Quote: Originally posted by Antiswat

mercury compounds are very very serious stuff, i recommend you watch "2 drops of organic mercury" before playing around any more with them, on a sidenote selenium can help you with avoiding absorbtion / toxicity of mercury i think a lot of safety is hypocrisy, you can find video from i believe his name is Nile Red on youtube where he pours various acids on his hands and even concentrated sulfuric acid started having an effect after around a minute but when it comes to toxic chemicals the only guideline you should follow is that the absolutely minimum exposure is the only acceptable, but even in our everyday life are we exposed to worse chemicals than the average chemist deals with in their free time, mercury is found in foods that are made with high fructose corn syrup as its made from corn syrup and sodium hydroxide- around 50% of sodium hydroxide being made with mercury electrode, not to mention tuna and salmon cadmium in chocolate even salad have many times tested positive for lead my worst accidents with chemistry would be long time ago where i decided to concentrate sulfuric acid in a stainless steel pot over flame, when i went to check up on it i was met with a wall of SO3, stepped back, took a deep breath and dived in to do what had to be done another time oxalates had formed chlorine gas with bleach, i accidentally inhaled a very small amount of chlorine and i had to spend a day in my bed hoping i would have nothing permanent out of it and yet another time i was burning off some magnesium powder on a spatula in a flash with NO2, i didnt realize there was a tiny bit of concentrated nitric acid in there, some of the burning metal fell off, reacted with the nitric acid, formed -- within a splitsecond large amounts of hydrogen and NOx and the flask transformed itself into a 7point jet aimed directly at my fingers - 2 days with hand in cold water and about a month to heal up, and this is the accidents ive managed to have for over 10 years dealing with chemistry oh and a heads up, you wanna avoid mixing acetone with chlorine or iodine, teargas is too easy to make and it hurts really bad

I make Iron(III) selenite heptahydrate (Fe2(SeO3)3 x 7H2O). It is a nice yellow compound. I found link. They are identical.

https://onyxmet.com/index.php?route=product/product&prod...

Quote: Originally posted by DraconicAcid

You love cadmium? Hmmmm....no accounting for taste- I can't see it being any more interesting than zinc, an element famed for its dullness. But that's a very pretty iron selenite. Can you make the iron(II) one as well?

Quote: Originally posted by vano.kavt

Yes it is like Ukraine here. I know people who bought chemicals after the collapse of the Soviet Union and this chemicals are not registered. This is a heaven for chemists. I can buy everything and everything is cheap. Here are some regulations, for example you cant buy potassium permanganate(but i have lot), but you can buy cadmium, uranyl and thorium compounds. Every acid is legal. For example nitric and hydrochloric acid cost 6 Lari, which is less than 2$. I bought two weeks ago 1 kilo copper one chloride and I paid 2$ for it. 100g Selenium cost 1.5$. The most expensive one I saw was hydrofluoric acid. Hydrofluoric acid cost 50$. The best thing is that I am the only buyer in the whole city and I have no concurents. [Edited on 5-12-2020 by vano.kavt]

Quote: Originally posted by AJKOER

Otherwise, nice work!

Quote: Originally posted by valeg96

Lucky! Chemicals here in europe are very expensive, and some are outright banned. Unfortunately we're far away so it's hard to trade things, or I would definitely buy something from you!