making Nickel Chloride

[Arthur Dent]

In my never-ending quest to prepare inorganic salts for my various experiments in electroplating, I was attempting to prepare a small amount of Nickel Chloride by using shards of 99.9% nickel with concentrated HCl, but I guess that what's missing is some sort of oxidizer because the reaction is nil... nothing, nada! There's some very weak bubbling after an hour, but nothing to write home... no "green" color at all.

 

A while ago, I had prepared succesfully some Zinc Chloride using the same basic process, but in that case, the reaction was vigorous and when it subsided, I had some relatively pure ZnCl2.

 

So here I have a becher with a few grams of nickel and about 20 ml of HCl (20 BE). Is there a reagent that I can safely and carefully add to the content to kickstart the reaction?

 

Robert

[ercdndrs]

Heat?

[Arthur Dent]

Hm, okay then. I have to admit I'm always a bit weary of heating-up strong acids on a hotplate (I do have one for outside use), but I thought maybe if I added a bit of H202, it would accelerate the process.

 

So i'll try just heat this weekend, hoping to keep the reaction under control. After two days, the becher exhibits a very pale greenish color, and there are quite a few bubbles on the nickel itself.

 

Robert

[UC]

Nickel is much lower on the electromotive series than zinc, and the reaction is less energetically favorable- in other terms, slower.

 

Outside or in a fume hood, you could add nitric acid or sodium nitrate (though you will need to remove the sodium chloride from the product) to make the oxidizing mixture known as aqua regia (or poor man's aqua regia for the sodium nitrate version, potassium nitrate would be okay as well- don't use ammonium nitrate). This gives off all sorts of nasty fumes (hence outside), but will even dissolve gold, which normally does not react at all with hydrochloric acid.

[rogerxd45]

if you add nitric acid wont you get a mix of nickle nitrate and nickle chloride?

 

 

it does work with pure HCL it just takes a long time, i left mine to site for a few weeks and then finally the nickle was gone. . i just covered the jar with a "watch glass" that would let the H2 out so pressure wouldnt build up

[Tartaglia]

Well aqua regia will certainly work, but I expect it is a "sledge hammer to crack a nut" approach. The NO3- is non coordinating and nitrate salts are often far more soluble than chlorides, so it may be less of a problem than first appears.

I suspect the oxidation is a kinetic problem rather than a thermodynamic problem, but tbh NiCl26H2O is so cheap I would just buy a little bit!

[Arthur Dent]

Thanks for the advice... I do have HNO3 but don't want to create a mixture of nitrate and chloride so I guess i'll let things simply sit. My goal would be to have relatively pure stuff, so I'd like to avoid using chemicals that would contaminate my final product.

 

@rogerxd45, I did something similar to your watchglass protecting the mixture, I used a piece of duct tape (I'm canadian, heh!)...

 

As for buying Nickel Chloride, I do have a nice chem provider in my neighborhood (Prolab Scientific) but the prices are a bit high and I just like the challenge of making my own stuff up! (especially for small quantities)

 

I usually order stuff from ProLab that I can't make myself and is relatively inexpensive.

 

Robert