Sciencemadness Discussion Board - How do I recognize metallic Nickel?

Are there other tests? I tried putting it in a CuSO₄ solution, and it didn't turn green as iron does, but it's not enough.. I can't come up with any test for metallic nickel. Any idea? Thanks!

Iron should turn copper-colored when it is placed in a CuSO₄ solution, because it does a redox reaction with the copper ions and metallic copper will plate its surface. Perhaps you meant the solution turns green? Nickel, like Iron is more reactive than copper, so it should get copper-plated too.

Wikipedia says NiCl₂.(H2O)₆ is green, but the anhydrite is yellow, so that seems like a good test. Also, I don't think Ni is as susceptible to oxidizing anywhere near as fast as iron does. Put a nail in one test tube and your metal in another and add just a little NaCl solution and see if they react similarly or not.

[Edited on 25-4-2014 by Artemus Gordon]

Oscilllator - 25-4-2014 at 15:33

Add nitric acid or a HCl/H2O2 mixture. If nickel is present, this should form a green solution of Ni2+. The fact that the metal is magnetic though is a very strong indicator that what you have is nickel.

[Edited on 25-4-2014 by Oscilllator]

Zyklon-A - 25-4-2014 at 15:47

You won't find any metallic nickel in Ni-Cd batteries anyhow. A charged battery will have metallic cadmium and nickel oxide hydroxide. A dead battery will have nickel hydroxide and cadmium hydroxide - elemental nickel is never present. (Ref.)

[Edited on 26-4-2014 by Zyklonb]

alexleyenda - 25-4-2014 at 15:52

I guess you ask this because you look for nickel... If you have any chance, come visit Canada, our 5, 10 and 25 cents coins made from 1968 to 1999 are 99,9% nickel :p Or just try to find some, maybe at an international money exchanger ?

[Edited on 25-4-2014 by alexleyenda]

Brain&Force - 25-4-2014 at 15:55

Nickel is magnetic, but only to a very small extent. It's ferromagnetic, but only poorly.

valeg96 - 25-4-2014 at 15:59

Quote: Originally posted by Artemus Gordon

Wikipedia says NiCl₂.(H2O)₆ is green, but the anhydrite is yellow, so that seems like a good test. Also, I don't think Ni is as susceptible to oxidizing anywhere near as fast as iron does. Put a nail in one test tube and your metal in another and add just a little NaCl solution and see if they react similarly or not.
[Edited on 25-4-2014 by Artemus Gordon]

I tried with HCl and it gives off a yellow solution. I'll try with H2O2 too. If it's not Ni at least i got some NiO(OH) from the same electrode and some powdered Cd from the other one... Anyway, the solution didn't turn green (that's what i meant), but i'll check it later.

valeg96 - 25-4-2014 at 16:04

Quote: Originally posted by alexleyenda

I guess you ask this because you look for nickel... If you have any chance, come visit Canada, our 5, 10 and 25 cents coins made from 1968 to 1999 are 99,9% nickel :p Or just try to find some, maybe at an international money exchanger ?

[Edited on 25-4-2014 by alexleyenda]

Some european pre euro coins are made of nickel too, but they are harc to find and you can't be sure of its purity. Pre euro dutch are said to be pure, and pre 1980 french also. I have a couple, but being old ones... The international exchanger may be a good idea, even though they mostly (almost only) change notes.

HgDinis25 - 25-4-2014 at 16:14

Zyklonb is absolutly right. Many Ni/Cd batteries have Steel plates and strips, to hold the chemicals toghether.

To test between Iron/Steel or Nickel, dissolve your unknown metal in Nitric Acid. If it's Nickel it will produce Nickel (II) Nitrate (Greenish Blue in color). If it's Iron it will produce Iron (III) Nitrate (ligh pink in color).

valeg96 - 25-4-2014 at 16:25

Zyklonb is absolutly right. Many Ni/Cd batteries have Steel plates and strips, to hold the chemicals toghether.

To test between Iron/Steel or Nickel, dissolve your unknown metal in Nitric Acid. If it's Nickel it will produce Nickel (II) Nitrate (Greenish Blue in color). If it's Iron it will produce Iron (III) Nitrate (ligh pink in color).

I'll dissolve my metal and a franc nickel coin to compare them better. Thanks!

blogfast25 - 26-4-2014 at 04:04

I tried with HCl and it gives off a yellow solution. I'll try with H2O2 too.

Nickel won't dissolve in HCl alone, you need an oxidiser like H2O2 or HNO3 present.

But Iron would dissolve in HCl to green FeCl2, not yellow. In HCl + H2O2 to yellow FeCl3.

[Edited on 26-4-2014 by blogfast25]

unionised - 26-4-2014 at 08:52

I tried with HCl and it gives off a yellow solution. I'll try with H2O2 too.

Nickel won't dissolve in HCl alone,

[Edited on 26-4-2014 by blogfast25]

Oh yes it does.

Texium - 26-4-2014 at 09:11

Here is a thread in which I was trying to identify a metal that ended up being nickel:
http://www.sciencemadness.org/talk/viewthread.php?tid=29408

Maybe it could be of some help?

HgDinis25 - 26-4-2014 at 17:58

I tried with HCl and it gives off a yellow solution. I'll try with H2O2 too.

"Nickel(II) chloride is produced by dissolving nickel or its oxide in hydrochloric acid." - http://en.wikipedia.org/wiki/Nickel

"The largest scale production of nickel chloride involves the extraction with hydrochloric acid of nickel matte and residues obtained from roasting refining nickel-containing ores." - http://en.wikipedia.org/wiki/Nickel%28II%29_chloride

"Iron, cadmium, cobalt, nickel, tin and lead are not reactive with water, but can be dissolved with hydrochloric acid, displacing the hydrogen from the HCl." - http://www.ehow.com/info_8106469_elements-react-hydrochloric...

Standar Reduction Potential Table:
http://hyperphysics.phy-astr.gsu.edu/hbase/tables/electpot.h...

Ni(s) --> Ni(+) + 2 e(-) 0,23 V
H(+) + 2 e(-) --> H2(g)

You get a positive voltage outcome, so the reaction occurs.

It appears you're wrong.

[Edited on 27-4-2014 by HgDinis25]

elementcollector1 - 26-4-2014 at 18:06

Heh. Alright, HgDinis25, you got us. Now find the reaction rate.

HgDinis25 - 26-4-2014 at 18:31

Quote: Originally posted by elementcollector1

Heh. Alright, HgDinis25, you got us. Now find the reaction rate.

Always remember that the only one who doesn't make mistakes is the one who doesn't say anything.

Even when you know most of your reaction variables, finding an acurate reaction rate is hard. Now try to findo it without even knoing the nature of your reagents...

BromicAcid - 26-4-2014 at 18:42

Amusingly when I go to scrap yards to ask for metals their go-to test is the spark test. They just hold the metal against an angle grinder and watch the sparks, nickel if I recall gives no sparks.

elementcollector1 - 26-4-2014 at 18:54

True enough.
To give you a hint, the rate of reaction is experimentally slow: I still have the leftover nickel foil scraps from when I dissolved neodymium-iron-boron magnets in HCl - the dissolution taking a few days!

blogfast25 - 27-4-2014 at 01:16

It appears you're wrong.

My practical experience with nickel and non-oxidising acids is that it's very slow.

HgDinis25 - 27-4-2014 at 03:55

It appears you're wrong.

My practical experience with nickel and non-oxidising acids is that it's very slow.

Slow, yet existing.

cyanureeves - 27-4-2014 at 06:29

this topic has come up before and i believe thin stainless steel was found to be used in nickel cadmium batteries.i did manage one time to plate a film of a mirror like skin using hydrochloric acid as dissolving solution. i never knew if the nickel salt was on the gray matter or darker matter in the battery though. i thought the greenish gray stuff in the battery was the cadmium but i dont know.nickel is hell to dissolve with hydrochloric acid and so is stainless steel,it might tint it green but dissolve it without heat,electricity or an oxidizer,i dont know.

valeg96 - 27-4-2014 at 06:44

It appears you're wrong.

My practical experience with nickel and non-oxidising acids is that it's very slow.

Slow, yet existing.

If that applies also to NiOOH that may explain why 2 tiny crumbles of it took hours to dissolve in 32% HCl...

valeg96 - 27-4-2014 at 06:48

Quote: Originally posted by cyanureeves

i never knew if the nickel salt was on the gray matter or darker matter in the battery though.

The darker crumbly and magnetic part is NiOOH and the greyish harder part is some Cd compound. The Cd compound is harder to remove, and after a lot of scratching I lost my temper and safely burnt it all, getting crumbly brown CdO. I still can't find a use for NiOOH, though.

[Edited on 27-4-2014 by valeg96]

Zyklon-A - 27-4-2014 at 08:26

Cadmium is why I take apart these batteries, nickel is easy to get. Cadmium isn't as easy, so I think Cd is a better find anyway.

blogfast25 - 27-4-2014 at 10:30

Slow, yet existing.

So slow it's impractical.

Example: I've dissolved loads of Nd magnet scrap in conc. hot HCl in the past. The magnets have a considerable gauge of Ni coating. I crush up the magnets (after demagnetising them) slightly, then let the acid do the work. I find the nickel coatings back, almost unaltered and in their original shapes.

Nitric acid is by far the best solvent for nickel. I've tried blends too: sulphuric/nitric for instance. Well, it's quite simple: once the nitric has been depleted the dissolution stalls.

unionised - 27-4-2014 at 13:07

Perfectly practical.
I used HCl a week or so ago to strip the nickel plating from some brass.
It works a lot better if the acid is warm.

Do you know how galvanising works?

Texium - 27-4-2014 at 13:24

Well, if it's just a thin plating it's a lot more practical than a heavier gauge coating or a larger piece. For me, it took about four hours for a fairly thick nickel plating to completely react with slightly above room temperature conc. HCl.

blogfast25 - 28-4-2014 at 04:33

Perfectly practical.
I used HCl a week or so ago to strip the nickel plating from some brass.
It works a lot better if the acid is warm.

Do you know how galvanising works?

Aren't you kind of making my case for me? A week??

Galvanisation doesn't explain why these nickel coatings didn't dissolve. Nor why some electro plated silver nickel spoons of mine didn't dissolve in H2SO4 after I had nitric stripped off the silver.

Nickel does dissolve in HCl and H2SO4 but it is very slow.

[Edited on 28-4-2014 by blogfast25]

Zyklon-A - 28-4-2014 at 05:00

Perfectly practical.
I used HCl a week or so ago to strip the nickel plating from some brass.
It works a lot better if the acid is warm.

Do you know how galvanising works?

Do you know how galvanizing works?
That isn't galvanizing, that's just nickel plating.
Galvanizing, is completely different:http://www.example.com

[Edited on 28-4-2014 by Zyklonb]

unionised - 28-4-2014 at 11:44

"Aren't you kind of making my case for me? A week?? "
If I had done it ten years ago would that have made it slower somehow?
I didn't say that it took a week.

And yes, I do know how galvanising works.
Specifically, it's using zinc plating to stop the corrosion of steel.
It works because the more reactive zinc dissolves first.

Now consider the nickel plating on a NIB magnet.
It's in the same position as the iron in galvanised iron.
It's in electrical contact with a more reactive metal- so it will dissolve slowly (if at all).
Did you not realise that the galvanisation analogy is why the Ni coating on magnets survives?

Happy now?

blogfast25 - 28-4-2014 at 11:51

Did you not realise that the galvanisation analogy is why the Ni coating on magnets survives?

Sorry, I misread you on the 'week'.

I know what you're referring to with the galvanisation analogy. But that's not what happens here. When the NdFe filling has been fully consumed, the Ni still didn't dissolve. Well, very slowly of course. Same with the silver coated nickel spoons: even when the silver is removed reaction with H2SO4 is really slow.

[Edited on 28-4-2014 by blogfast25]

unionised - 28-4-2014 at 12:27

Incidentally, "nickel" spoons are likely to be this stuff
http://en.wikipedia.org/wiki/Nickel_silver
which is largely copper - so you wouldn't expect it to be attacked by HCl and only slowly by H2SO4.

blogfast25 - 28-4-2014 at 12:59

Incidentally, "nickel" spoons are likely to be this stuff
http://en.wikipedia.org/wiki/Nickel_silver
which is largely copper - so you wouldn't expect it to be attacked by HCl and only slowly by H2SO4.

That I'm certainly willing to investigate, having plenty more of these spoons, marked EPNS...

[Edited on 28-4-2014 by blogfast25]

unionised - 29-4-2014 at 12:09

Electro
Plated
Nickel
Silver
isn't going to dissolve well without an oxidant.

So, the reason you think nickel doesn't dissolve is that you were actually mainly using copper when you did the experiment.

HgDinis25 - 29-4-2014 at 13:32

I haven't seen any spoons with that alloy. Quite interesting.

Anyway, knowing what one is using in a chemical reaction is a MUST. Always research about what metals might be present in the items you use, blogfast25. And if you have any doubts on it, you can always use the Beginnings forum to help you out.

LanthanumK - 30-4-2014 at 14:18

I tried to extract metals from a nicad battery. Never got anything but a mess.

cyanureeves - 30-4-2014 at 14:41

a million years ago i took parts to a galvanizing plant and i saw them dunking huge skids platforms into a gigantic tank with steaming hot zinc.

blogfast25 - 1-5-2014 at 04:41

So, the reason you think nickel doesn't dissolve is that you were actually mainly using copper when you did the experiment.

I think I should test that first before we posit this as certainty.

unionised - 1-5-2014 at 06:20

Good point.
Are they magnetic?

blogfast25 - 1-5-2014 at 08:40

Haven't tested that yet.

unionised - 3-5-2014 at 07:17

Would it help if I sent you a magnet?

blogfast25 - 3-5-2014 at 12:48