Sciencemadness Discussion Board - Light blue hydroxide

Light blue hydroxide

Romix - 26-12-2015 at 04:19

Hello Dear forum members, please help me identify chloride salt.
Its anhydrous yellow.
Salt is very light, between green and blue.
With NaOH light blue hydroxide formed.
Same, with very diluted ammonia.
Not nickel, cos it should form complex with it.
No reduction with aluminium.

ave369 - 26-12-2015 at 05:04

Might be some rare earth?

Romix - 26-12-2015 at 05:12

white with light blue tint

Romix - 26-12-2015 at 05:14

Will decompose sample of it, to oxide, I let you know colour later. And flame.

Romix - 26-12-2015 at 15:44

Its oxide is grey.

[Edited on 26-12-2015 by Romix]

Romix - 29-12-2015 at 13:23

Quote: Originally posted by ave369

Might be some rare earth?

Which one? maybe neodium?

Romix - 31-12-2015 at 16:14

Chloride salt

Anhydrous

Hydroxide, with NaOH solution became colourles after nuetralization, with ammonia solution still green after all light blue unknown to me hydroxide precipitated, that's it on picture. Not forming complex.

Decomposed sample of it, to grey oxide, which is non-magnetic.

Please help.

[Edited on 1-1-2016 by Romix]

The Volatile Chemist - 31-12-2015 at 16:26

Perhaps some clarity as to source, method of acquisition (not necessary, helpful though). Do the stoichiometry of mass change when the grey oxide is formed, that may or may not be helpful.
Possibly this?
https://en.wikipedia.org/wiki/Praseodymium%28III%29_chloride
Fits your oxide identification:
https://www.google.com/search?q=Praseodymium%28III%29+oxide&...

Romix - 31-12-2015 at 16:45

And yea, happy new year to all you dear forum members.

The Volatile Chemist - 31-12-2015 at 21:24

Indeed, it's a new year just now for me. Does my suggestion above fit the compound? Perhaps do some more testing.

Romix - 1-1-2016 at 02:44

Quote: Originally posted by The Volatile Chemist

Indeed, it's a new year just now for me. Does my suggestion above fit the compound? Perhaps do some more testing.

Testing? How?

[Edited on 1-1-2016 by Romix]

The Volatile Chemist - 6-1-2016 at 13:41

Well, I find it likely it's Praseodymium(III) Chloride. Perhaps you should look up some properties of praseodymium(III) ions and see if you can figure it out

Don't leave all the science to other members!

Romix - 17-4-2016 at 09:20

Quote: Originally posted by The Volatile Chemist

Well, I find it likely it's Praseodymium(III) Chloride. Perhaps you should look up some properties of praseodymium(III) ions and see if you can figure it out

Don't leave all the science to other members!

Can be, how you know?

[Edited on 17-4-2016 by Romix]

Romix - 17-4-2016 at 09:25

At the start it's purple, then colorless.
Valency change?
Then turning green, possibly nickel starting oxidizing, or reacting with solution.

Carbonate and hydroxide. same colour.

[Edited on 17-4-2016 by Romix]

Romix - 17-4-2016 at 09:32

Titanium is other way roud, first it's green, then oxidizing to purple.
Ti? When green, green drops, when purple, pink-purple, when precipitated with base.

[Edited on 17-4-2016 by Romix]

Romix - 17-4-2016 at 09:38

Iron is brown when in II state and green in third. As written in books, it's true.
When standing on air, green oxidising to brown. Happens quick.

[Edited on 17-4-2016 by Romix]

Romix - 26-6-2016 at 18:34

Quote: Originally posted by Romix

Iron is green when in II state and brown in third. As written in books, it's true.
When standing on air, green oxidising to brown. Happens quick.

[Edited on 17-4-2016 by Romix]

bolbol - 4-7-2016 at 16:55

The only chloride I can think of with that smiliar color are copper, nickel, and praseodymium chlorides. Are you sure it is a pure sample?

Texium - 4-7-2016 at 17:48

We need more information, such as where it came from. For all we know you found this laying in the street. Where did you get it, and are you sure it's a pure compound?

Romix - 15-8-2016 at 15:15

No. dirty. Ceramics of dissolved capasitors.
In first valency it were purple.

Collected more of this, jar full of it.
Yes there could be nickel present in it.
And tin, I'll try to remove it on the next wash up.

[Edited on 15-8-2016 by Romix]

NEMO-Chemistry - 15-8-2016 at 17:03

could it be tantalum? some small ceramic capacitors contain Tantalum, but i know nothing of its chemistry.

Romix - 16-8-2016 at 02:28

Quote: Originally posted by NEMO-Chemistry

could it be tantalum? some small ceramic capacitors contain Tantalum, but i know nothing of its chemistry.

No, doubt it. Tantalum is in yellow and black plastic case capacitors, wire inside and oxides. These are MLCC. With nickel plates inside.
And I tried boiling Ta2O5 in muriatic acid and caustic soda, none of it dissolved.

There could be anything, all removed from different brand boards, and years vary.

[Edited on 16-8-2016 by Romix]

Romix - 14-9-2016 at 04:02

Does look like Sn+*, but not tin.

[Edited on 14-9-2016 by Romix]

MrHomeScientist - 14-9-2016 at 05:36

Sounds a lot like copper chloride to me. Anhydrous is brown, hydrated chloride is green, hydroxide is blue. The grey oxide doesn't fit, since it should be black, but maybe there was incomplete decomposition. How hot did you heat it, and for how long?

crystal grower - 14-9-2016 at 06:33

Quote: Originally posted by MrHomeScientist

Sounds a lot like copper chloride to me. Anhydrous is brown, hydrated chloride is green, hydroxide is blue. The grey oxide doesn't fit, since it should be black, but maybe there was incomplete decomposition. How hot did you heat it, and for how long?

copper chloride is what came to my mind first (I've noticed this thread today as you posted this reply

).
Try dissolving carbonate or hydroxide in sulfuric acid to see what colour does the sulfate is.

Romix - 15-9-2016 at 12:44

Quote: Originally posted by crystal grower

Quote: Originally posted by MrHomeScientist

copper chloride is what came to my mind first (I've noticed this thread today as you posted this reply

).
Try dissolving carbonate or hydroxide in sulfuric acid to see what colour does the sulfate is.

No, there ain't a tenth of a procent of Cu+2 there.
You can clearly see Ni by the colour of complex.
And hydroxide of copper is dark blue! You are wrong.

[Edited on 15-9-2016 by Romix]

MrHomeScientist - 19-9-2016 at 06:06

If you're so confident it's nickel, why ask at all?

Have you done any actual tests for ions, or were you too busy dismissing our ideas out of hand?

Metallus - 21-9-2016 at 08:19

Try adding potassium iodide or sodium bisulfite in acidic solution or sodium bisulfite. Most transition metal ions in higher oxidation states are mild/strong oxidants, so a reaction may occur.

Also, when I first looked at the pic you posted, I immediatly thought of copper chloride as well.

It's true, addition of ammonia will lead to the formation of a dark blue complex.... that is if you pour a lot of ammonia. If you added just a few drops, the hydroxide will precipitate out just because of the pH increase.

Try drowning that salt in ammonia and tell us the results.

crystal grower - 21-9-2016 at 11:00

Simply precipitate carbonate, dissolve in sulfuric acid and let the sulfate crystallize. From the appearance of the crystals one can easily tell what metal ion is present.

xfusion44 - 22-9-2016 at 03:09

This is copper chloride, for comparison:

Anhydrous (green pieces are a bit moist)

Solution with low concentration of chloride ions (higher concentration makes solution more greenish)

Romix - 25-9-2016 at 09:41

Quote: Originally posted by Metallus

Try adding potassium iodide or sodium bisulfite in acidic solution or sodium bisulfite. Most transition metal ions in higher oxidation states are mild/strong oxidants, so a reaction may occur.

Also, when I first looked at the pic you posted, I immediatly thought of copper chloride as well.

It's true, addition of ammonia will lead to the formation of a dark blue complex.... that is if you pour a lot of ammonia. If you added just a few drops, the hydroxide will precipitate out just because of the pH increase.

Try drowning that salt in ammonia and tell us the results.

Ok, would oxide, hydroxide, carbonate of nickel dissolve in ammonia solution? Or precipitated mixture better to be dissolved in acid, before addition of (aq) NH4OH. Metallic Ni reacts very very slow, compare to copper.

[Edited on 25-9-2016 by Romix]

Metallus - 27-9-2016 at 02:45

Quote: Originally posted by Romix

Quote: Originally posted by Metallus

Yes, when you drown your precipitated oxide/hydroxide in ammonia, a good part should re-dissolve. I never tried dissolving a carbonate with ammonia, so you may try to first bubble out all the CO2 in acid solution, then neutralize and add ammonia.

This was part of a lab experience my professor made me do: precipitation of copper/zinc hydroxide with a few drops of ammonia, and then re-dissolution when a lot of ammonia is added.

Co, Ni, Cu, Zn behave like that and they all give different colors (magenta, violet, deep blue and colorless respectively).

[Edited on 27-9-2016 by Metallus]

Camroc37 - 27-9-2016 at 18:07

Quote: Originally posted by Romix

At the start it's purple, then colorless.
Valency change?
Then turning green, possibly nickel starting oxidizing, or reacting with solution.

Carbonate and hydroxide. same colour.

[Edited on 17-4-2016 by Romix]

Possibly Vanadium? Not sure though

Metallus - 11-10-2016 at 07:33

This may come into hand when you need to differentiate colors in different mediums.

http://www.docbrown.info/page07/SSquestions/transppt.gif

If it's vanadium, then it should give some signs of reaction with reductants (in which case, try acid solution of bisulfite; it should turn from yellow/orange -> light blue)

AJKOER - 17-10-2016 at 14:25

What is the source of the salt?

If a school project, not likely an expense salt.

From electronic equipment,...., which may give clues.

Try a flame test.

Heat it to glowing or nearly so and drop it into a bottle of hydrogen. Carefully smell ( you may wish to check first with the teacher if this would be a reasonably safe procedure for the sample of salts distributed to the class) the gas and examine any metal liberated, including its color, density, melting point, reactivity to water, dilute and strong acid.

[Edited on 18-10-2016 by AJKOER]