Sciencemadness Discussion Board

How can i reduce NiO to Nickel?

Sally - 27-8-2013 at 13:42

How can i reduce Nickel(II) oxide to Nickel?

Can i make this with a home lab?

Please give me an example with 10g NiO

Thanks!

elementcollector1 - 27-8-2013 at 14:12

What form would you like the nickel to be in?
If you'd like nickel powder, a likely answer is to dissolve the oxide in an acid, then add aluminum to precipitate out nickel metal (single substitution reaction).
For the advanced, you could mix the powdered nickel oxide with powdered aluminum metal, and initiate it with a small amount of potassium permanganate and glycerin. This will initiate a very hot conflagration known as 'thermite', and at the end you should have a few small lumps of elemental nickel metal.
Ni(2+) + Al -> Ni + Al(3+) (in solution of dissolved nickel salt)
3NiO + 2Al -> 3Ni + Al2O3 (thermite)

From that, you can use the molar masses to determine how much powdered aluminum or solid aluminum you'll need to react perfectly with your nickel. A helpful site is http://theodoregray.com/PeriodicTable/MSP/BalanceReactions

cyanureeves - 27-8-2013 at 14:17

Sally did you make this oxide?nickel oxide is getting expensive now.

Sally - 27-8-2013 at 14:53

@elementcollector1

I need it in powder form. Do i only need to dissolve 10g NiO in X ml of HCl and then add x g Al-Powder?

Can you please say how much HCl an Al-Powder do i need to reduce 10g of NiO

@cyanureeves

unfortunately, not

elementcollector1 - 27-8-2013 at 15:04

Quote: Originally posted by Sally  
@elementcollector1

I need it in powder form. Do i only need to dissolve 10g NiO in X ml of HCl and then add x g Al-Powder?

Can you please say how much HCl an Al-Powder do i need to reduce 10g of NiO

Sure. So, to convert 10g of NiO to moles NiO, you would need the molar mass, which from Wikipedia is roughly 74.7 g/mol. 10g/74.7g tells us that you have roughly 0.134 moles of NiO.
Now, we need a balanced equation for the reaction:

NiO + 2HCl -> NiCl2 + H2O

For every given molar amount of NiO, we need twice that of pure HCl. Now, hydrochloric acid is not pure HCl, but a solution in water. I will need to know the strength of the acid (concentration) to go any further.

Metacelsus - 27-8-2013 at 15:57

The molar mass of HCl is 36.46 g (Wikipedia)
Thus, you will need 9.77 g HCl (0.286 mol) for the reaction. However, as elementcollecter1 stated, this is not equivalent to grams of hydrochloric acid.

For example, hardware-store grade hydrochloric acid is 31.45% HCl by mass (at least at my hardware store). Thus, you will need 9.77 / 0.3145 = 31.07 g of 31.45% hydrochloric acid to completely react the nickel.

bbartlog - 28-8-2013 at 04:56

If you precipitate the metal using aluminum, you do still have the problem of separating the nickel from the resulting alumina.
A possible alternative is to convert the NiO to nickel oxalate and then thermally decompose this (requires temperature of about 300C), which results in a fine nickel powder, albeit one still slightly contaminated with NiO.

Morgan - 28-8-2013 at 05:55

Perhaps you could use a magnet mounted on a rod wrapped in plastic to attract the nickel and then peel the plastic off with the metal powder.

elementcollector1 - 28-8-2013 at 06:49

Quote: Originally posted by bbartlog  
If you precipitate the metal using aluminum, you do still have the problem of separating the nickel from the resulting alumina.

If I use a solution of chloride, the end-product is aluminum chloride, which is soluble in water.

ElizabethGreene - 29-8-2013 at 14:25

Hello.

From my recent plating experiments I've found that nickel sulfamate solution will precipitate a nickel powder (I've assumed it's elemental Nickel, someone double check that...) if you use "too much" current. "Too much" current is arbitrarily defined as the number 6 on my variable transformer. I'm sorry I didn't have an ammeter on it at the time.

You could try
2HCl + NiO = NiCl2 + H20

and Electrolysis
Cathode: Ni2+ + 2 e– → Ni(s) E° = –0.24 v
Anode: 2 Cl– → Cl2(g) + 2 e– E° = –1.36 v

Good luck!

Protium1 - 29-8-2013 at 21:13

NiO can be reduced to Ni elemental by heating in a hydrogen atmosphere...not as difficult as it sounds, though Ni powder can be spontaneously flammable in an open atmosphere, so BE WARNED.
Fairly pure hydrogen can be produced using DC electrolysis of water.
Pipe H2 through a tube furnace (high-temp glass or preferrably quartz glass) containing NiO and heat using flame or electric elements.

elementcollector1 - 30-8-2013 at 08:38

Quote: Originally posted by Protium1  
NiO can be reduced to Ni elemental by heating in a hydrogen atmosphere...not as difficult as it sounds, though Ni powder can be spontaneously flammable in an open atmosphere, so BE WARNED.
Fairly pure hydrogen can be produced using DC electrolysis of water.
Pipe H2 through a tube furnace (high-temp glass or preferrably quartz glass) containing NiO and heat using flame or electric elements.


I would not recommend working with hydrogen when easier alternatives are available - after all, nickel doesn't react with water, so aqueous solution really is the way to go.

AJKOER - 30-8-2013 at 15:57

Heat Ni(OCH3)2 in a hydrogen medium (reference see page 11 at http://www.technetium-99.ru/Presentations/Mazilin_Ivan.pdf ). This actually forms a nano-sized highly reactive Nickel.

If Ni(OCH3)2 is heat in air, you get the highly reactive nano-sized NiO. So, by doing it in H2, it quickly forms Ni. In general for Metal alkoxide, this is a low temperature synthesis (under 300 C).

To prepare Ni(OCH3)2, see http://en.wikipedia.org/wiki/Metal_alkoxide and page 490 at http://uqu.edu.sa/files2/tiny_mce/plugins/filemanager/files/... .

elementcollector1 - 30-8-2013 at 16:26

Again, the OP simply specified "Nickel powder". Unless nano-sized nickel is requested, I don't think this is necessary. It is a fascinating procedure, though - I might try it sometime.

AJKOER - 5-9-2013 at 13:22

Here is an interesting thought based on recent surprise I have with a Copper ammonium complex and the resulting formation of a gold colored liquid (actually, I suspect, nano-sized elemental Copper) upon reaction with Aluminum.

So, try an dissolve NiO in an excess of aqueous ammonia to form a Nickel hexaammine complex ion. See video at http://www.youtube.com/watch?v=PLoDRwVXSVI . Alternately, form a convenient soluble Nickel(II) salt and treat with an excess of ammonia.

Then, add Aluminum and wait a day or more.

Clearly a cheap path, but not fast. The quality of the product, however, may be surprising. :D

AndersHoveland - 5-9-2013 at 16:23

Typically poisonous hypophosphites are used to reduce nickel salts for nickel plating.

WGTR - 30-9-2013 at 21:02

I see that I'm jumping on this thread a little late, but I second the idea of using hydrogen. For temporary storage I will keep hydrogen in a "gas bag", essentially a sealed ziploc bag with a rubber hose poked tightly through the side of it. After taping the hose down, it kind of reminds me of an IV line stuck in the back of your hand. A hemostat can be used to clamp off the hose. In this case, you don't have to worry about being "killed by flying shards of broken ziploc bag" if something goes disastrously wrong...although you could conceivably lose your eyebrows.

When I needed small amounts of nickel powder, I'd spread the nickel oxide out in a horizontal test tube, release some hydrogen into the tube to flush out the other gasses, and then pipe the hydrogen into the sealed test tube through the stopper. Patient and gentle heating would reduce the nickel oxides, and water would condense in the cooler parts of the tube. As it was used up, more hydrogen would get sucked into the sealed test tube. The main caveat was that if you had not flushed the tube properly before sealing it, or if your hydrogen was not completely pure, the leftover nitrogen would build up and slow down the reaction, because it just stays in the tube. Also, water eventually builds up in the tube, so this only works for small samples.

After reduction, opening the cooled test tube under previously boiled water (deoxygenated) protected the nickel from air oxidation.

Now that I have a mini reaction tube that mounts on my hot plate, I just flow the reducing gasses straight through the tube. It's much easier that way.

Boffis - 1-10-2013 at 06:35

There are two very easy routes to nickel powder:

1) Dissolve the NiO in formic acid and isolate the soluble nickel formate and then thermally decompose as per the attached reference;

Attachment: Thermal decomposition of nickel formate.pdf (1.5MB)
This file has been downloaded 785 times

The main difficulty with this technique is that some commercial "nickel oxides" is either impure and contains significant iron oxide or has been "dead burnt". In both cases it requires prolonged boil with 15-20% HCl and the periodic addition of a little H2O2 to get it into solution. If a large excess of HCl is avoided most of the iron precipitate as brown ferric oxide hydrate. Once filtered the nickel can be re-precipitated in a more reactive form with either sodium hydroxide or carbonate, the latter often gives a more filterable product.

2) Alternatively once you have got the nickel in solution you can precipitate nickel powder directly by vigorously stirring with magnesium or zinc powder; if you avoid a large excess of magnesium the product can be fairly pure. There are whole threads on the preparation of active nickel catalysts by this technique with references posted on SM site; try a search on "Urushibara nickel".

bismuthate - 1-10-2013 at 15:12

reduce it with carbon monoxide!:P

Just kidding don't try that.