[zeshkani]

Would it be possible to separate the Co2+ and Ni2+ by precipitation with hydroxide? 

[Alberto_Kravina]

Would it be possible to separate the Co2+ and Ni2+ by precipitation with hydroxide? 

As far as I remember both cations form insoluble hydroxides, and both of these hydroxides are soluble in excess ammonia (assuming that you use ammonia to precipitate the hydroxides)....so I don't know if it is possible

[gypsum]

you can actually separate cobalt and nickel by using ion-exchange method by using a strong-base anion exchanger. many metals form their chloride complex at high HCl concentration and easily adsorbed by an anion resin, but other metals are not, like nickel. hence you can separate the two...

check: www.chem.uic.edu/chem222/handouts/DU.10-5.pdf

[remšak6]

Would it be possible to separate the Co2+ and Ni2+ by precipitation with hydroxide? 

No, not with hydroxide. It be possible with (Co2+) SCN- ions.

Co2+ + 4SCN- --> <--- [Co(SCN)4]2- It's chemical proof for Co2+ ion. This complex is blue color.

(Ni2+) you can proof on this way:

Your solution of ions (Co2+ has been proven) in test tube have to be a little acidity. Then you have to add diacethyldioksine (I don't know how exactly is correct.Acetil or actehyl? ) It'll to appear pink colur which is proof for Ni2+ ion.

That's all.

[Alberto_Kravina]

Then you have to add diacethyldioksine (I don't know how exactly is correct.Acetil or actehyl? )

You can call it either Diacetyldioxime (which is pretty different from a dioxine) or Dimethylglyoxime

[remšak6]

Ups. Sorry. I didn't know. I come from Slovenia. In Slovenian language is DIACETILDIOKSIN. Hehe. So for this reason it was wrong.

Thank you, very much!

lp

[zeshkani]

thanks