Sciencemadness Discussion Board - Cobalt selenite + photos

Cobalt selenite + photos

vano - 9-2-2021 at 08:13

Hi. Today i Made cobalt selenite dihydrate. It has very nice colour. Anhydrous selenite looks like anhydrous chloride. Now i have Sc, Cu, Fe3, Ni, Co, Mn, i also have small amount of Hg selenite. I want to make Fe 2, chromium and vanadyl selenites.

Now i have many cobalt sulfate and i think i will make lot's of cobalt compounds.
Wet selenite

Different from other selenites.

[Edited on 9-2-2021 by vano]

itsallgoodjames - 9-2-2021 at 11:50

Wow, those are super vibrant colors. I should get some selenic acid. I wonder what hexammine nickel selenite or tetraamminecopper selenite would look like?

DraconicAcid - 9-2-2021 at 13:40

The ammine complexes will probably look identical to the sulphates of the complexes. The ammine ligands will prevent the selenite from gtting into the coordination sphere and affecting the colours.

Bedlasky - 9-2-2021 at 17:11

Vano: I think, that ferrous ions will reduce selenite in to red selenium, try it first in test tube.

vano - 9-2-2021 at 22:36

Thanks everyone.

Unlike other selenites i have more Ni and Cu salt and i will try amino complexes.

Bedlasky: i will try in the test tube. I hesitate because it does not have such a good color. It has a white yellowish colour.

[Edited on 10-2-2021 by vano]

[Edited on 10-2-2021 by vano]

vano - 10-2-2021 at 10:44

Full is better

vano - 25-2-2021 at 01:24

Two weeks ago I made copper ammino complex. CuSeO3•2H2O is well soluble in ammonia solution. When i dissolved it then add large amount of isopropyl alcohol, but nothing precipitated. Next i boiled it, but I forgot to turn off the heater and it was heating at 200-250 degrees overnight. I finally got copper oxide.

vano - 25-2-2021 at 05:46

Bedlasky: i tried this reaction. Red selenium did not form, but look at the colour. It is a interesting, I don't know why this insoluble compound have such colour. I knew that divalent iron selenite is white yellowish solid. If this is selenite then i make more, but im not sure. What do you think?

I used iron sulfate hydrate, sodium selenite and warm, but not hot water.

vano - 25-2-2021 at 08:22

I filtered and washed. It looks like iron oxide. But i don't know exactly. I know that iron oxide have different colours. It depends on precipitation methods and other things, but i never seen oxide that has exactly same colour.

Bedlasky - 25-2-2021 at 09:44

Ferrous salts have sometimes strange colours. For example ferrous molybdate is brown (but it is unstable and quickly decompose in to ferric molybdate and molybdenum blue). But you a right that your precipitate look like ferric salt. But there is no red selenium present. Only one other product of reduction of selenite, which comes to mind, is selenoselenate Se₂O₃^2- (or you can write it as Se⁰Se^IVO₃^2-). But I really don't know if this is really reaction product. How filtrate look like? Fe(III) forms with thiosulfate purple complex, I suspect something similar with selenoselenate.

vano - 25-2-2021 at 10:08

Quote: Originally posted by Bedlasky

Ferrous salts have sometimes strange colours. For example ferrous molybdate is brown (but it is unstable and quickly decompose in to ferric molybdate and molybdenum blue). But you a right that your precipitate look like ferric salt. But there is no red selenium present. Only one other product of reduction of selenite, which comes to mind, is selenoselenate Se₂O₃^2- (or you can write it as Se⁰Se^IVO₃^2-). But I really don't know if this is really reaction product. How filtrate look like? Fe(III) forms with thiosulfate purple complex, I suspect something similar with selenoselenate.

Thank you for Interesting idea. Filtrate has yellowish colour, i think because of this insoluble compound particles, which penetrated filter paper. Anyway now we know how the reaction is going.

[Edited on 25-2-2021 by vano]

ChemTalk - 25-2-2021 at 20:50

Thanks for sharing. It is a nice purple color. Looks similar to Cobalt phosphate, cobalt tungstate and cobalt molybdate. One of my favorite cobalt compounds to make is cobalt ferrocyanide, it is quite a different color than most other cobalt compounds.

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ChemTalk
ChemTalk Experiments

[Edited on 2-26-2021 by ChemTalk]

Texium - 25-2-2021 at 22:42

Quote: Originally posted by ChemTalk

One of my favorite cobalt compounds to make is cobalt ferrocyanide, it is quite a different color than most other cobalt compounds.

Kind of a blue-green color if I remember correctly, right? Definitely unusual for cobalt.

vano - 26-2-2021 at 00:16

Quote: Originally posted by ChemTalk

Thanks for sharing. It is a nice purple color. Looks similar to Cobalt phosphate, cobalt tungstate and cobalt molybdate. One of my favorite cobalt compounds to make is cobalt ferrocyanide, it is quite a different color than most other cobalt compounds.

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ChemTalk
ChemTalk Experiments

[Edited on 2-26-2021 by ChemTalk]

My cobalt tungstate has different colour. Thanks for new idea, i will make ferrocyanide, but tell me if it precipitated instantly or stay in suspension like copper ferricyanide.

Texium - 26-2-2021 at 06:58

Cobalt ferrocyanide precipitates pretty instantly from what I remember, similarly to Prussian Blue. It’s a very fine precipitate.

vano - 26-2-2021 at 07:08

Quote: Originally posted by Texium (zts16)

Cobalt ferrocyanide precipitates pretty instantly from what I remember, similarly to Prussian Blue. It’s a very fine precipitate.

Thanks i will try.

ChemTalk - 27-2-2021 at 06:23

Vano, I made a video for you on Cobalt Ferrocyanide and uploaded it to our youtube channel.

It was just going to be one short clip, then I realized I had a couple other clips, so I combined them. So it took longer than I thought, but that is ok because it is one of my favorite compounds.

https://www.youtube.com/watch?v=MghE_Iyv9Bw

We are looking forward to see what further cobalt compounds you make!

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ChemTalk
ChemTalk Tutorials

[Edited on 2-27-2021 by ChemTalk]

vano - 27-2-2021 at 07:17

Quote: Originally posted by ChemTalk

Vano, I made a video for you on Cobalt Ferrocyanide and uploaded it to our youtube channel.

It was just going to be one short clip, then I realized I had a couple other clips, so I combined them. So it took longer than I thought, but that is ok because it is one of my favorite compounds.

https://www.youtube.com/watch?v=MghE_Iyv9Bw

We are looking forward to see what further cobalt compounds you make!

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ChemTalk
ChemTalk Tutorials

[Edited on 2-27-2021 by ChemTalk]

For me? Oh thanks. I subscribed your chanel. It has really unusual colour. I will make it. Thanks again.

vano - 27-2-2021 at 08:44

Very nice and unusually colored compound. Good for chemical colection. This compound has black, but nice greenish colour. Wet salt has very different colour.

ChemTalk - 28-2-2021 at 07:47

Oh, I'm really glad you made it. For me, the best part was seeing it settle in the test tube over a couple of days. The surface looked like an alien ocean, reminded me of the movie Solaris. I haven't filtered mine yet. And thanks for subscribing to the channel!
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ChemTalk
Chemistry Tutorials

[Edited on 2-28-2021 by ChemTalk]

vano - 28-2-2021 at 12:34

Quote: Originally posted by ChemTalk

Oh, I'm really glad you made it. For me, the best part was seeing it settle in the test tube over a couple of days. The surface looked like an alien ocean, reminded me of the movie Solaris. I haven't filtered mine yet. And thanks for subscribing to the channel!
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ChemTalk
Chemistry Tutorials

[Edited on 2-28-2021 by ChemTalk]

Thanks. Good luck!

Bedlasky - 23-3-2021 at 10:31

Quote: Originally posted by Bedlasky

I correct myself - I found that selenoselenate actually doesn't exist.