Sciencemadness Discussion Board

Accidentally made nickel oxide?

Amos - 5-9-2014 at 15:48

As part of my plan to obtain some pure(r) nickel salts, I decided to dissolve US nickels(25% nickel, 75% copper) in hydrochloric acid with some hydrogen peroxide to act as an oxidant. After a few days I had a very dark, nearly opaque green solution that would clarify to a deep blue-green transparent solution when more peroxide was added. However, during tonight's addition of hydrogen peroxide, instead of clarifying, the solution became clouded and milky, progressively lightening in color. After letting it settle I have a pile of what looks like nickel oxide! I've attached a picture; does anyone know what happened? I should add that this was a farily dilute solution of hydrochloric acid; I'm not sure how much cupronickel chloride I have in there yet.



IMG_0808.JPG - 2.4MB

hyfalcon - 5-9-2014 at 15:55

Ah, I think anything I had dissolved nickel salts in I would handle with some gloves on.

Morgan - 5-9-2014 at 16:45

Here's a relatively good source for pure nickel instead of using our 25% nickels. And they are quite attracted to a magnet, unlike our alloy nickels.
1964–1981 4.54 g 21.21 mm, round 99.9% nickel
http://en.wikipedia.org/wiki/Nickel_(Canadian_coin)

http://www.ebay.com/itm/1-lb-Canadian-nickels-bullion-1956-8...

http://www.ebay.com/itm/France-Coin-Lot-10-One-Franc-Coins-P...

Here's some 99% nickel if you need a larger quantity. ha
http://www.ebay.com/itm/26-LBS-200-Pure-Nickel-Wire-20-Gauge...

cyanureeves - 5-9-2014 at 16:47

i have precipitated copper in similar fashion and it looked white as snow even.

Amos - 5-9-2014 at 18:41

Quote: Originally posted by hyfalcon  
Ah, I think anything I had dissolved nickel salts in I would handle with some gloves on.


Probably a good idea in case I were to spill some, true. And I realize that I could of course purchase some pure nickel but the chemistry is where all the fun is!

cyanureeves said: "i have precipitated copper in similar fashion and it looked white as snow even."

Care to explain how you did that? I've precipitated copper powder with reducing agents before but this is the first I've heard of using hydrogen peroxide for it. And since you guys showed up to the post, what would you conclude the powder might be? If it's nickel oxide of a decent purity then I definitely need to find out how reproducible this might be.

cyanureeves - 5-9-2014 at 18:51

i used hydroxides.i just read that metal oxides turn to hydroxides in water so i would separate the precipitate and resume until i find which portion of precipitate contains more nickel than copper.

[Edited on 9-6-2014 by cyanureeves]

blogfast25 - 6-9-2014 at 04:10

Quote: Originally posted by No Tears Only Dreams Now  
After letting it settle I have a pile of what looks like nickel oxide! I've attached a picture; does anyone know what happened?


Why not isolate the precipitate and wash and dry it? Inspect its true colour (hard to see in a sea of green NiCl2).

Then dissolve in a hot, strong acid and see what colour you get? Adding ammonia to a neutralised solution should give a fairly characteristic colour of the nickelammine complex.

unionised - 6-9-2014 at 04:23

CuCl2 + Cu----> 2 CuCl

cyanureeves - 6-9-2014 at 05:48

No Tears Only Dreams Now you are correct about the reducers that precipitate white copper and the hydroxides are a bit colored. i hope you do get mostly nickel and i dont understand the reaction so i know i am not answering your question. unionised says you got 2 CuCl so the nickel is in solution?still somewhat isolating which is good.

Amos - 6-9-2014 at 11:52

Quote: Originally posted by unionised  
CuCl2 + Cu----> 2 CuCl


Thanks unionised! That's probably what has happened here, I can't believe I didn't recall the reaction. I'll test some of the powder and make sure there's no nickel in it; if that's the case, half of my work is done for me.