[plasticfood]

A solution contains the ions Ag+, Pb2+, and Ni2+. Dilute solutions of NaCl, Na2SO4, and Na2S are available to separate the positive ions from each other. In order to effectively separate, the solutions should be added one at a time in which order? (HINT: based on solubility rules; want to separate one ion out of solution at a time).

ok i am really confused on this one. i believe that i am to combine the Ag, Pb2, Ni2 with NaCl, Na2SO4, and Na2S to see which will give me an insoluble salt, right? so do i ignore the Na's, and just combine Ag, Pb2, Ni2 with Cl, SO4, and S, and use the solubility rules? but then what? am i supposed to look for the ones that are aq or s?    

fundamentally, i have no clue what the question really means. by "separating", does that mean to form an insoluble salt or what??

[opti384]

I think the key point here is that you have to effectively separate and that the question asks in which order should you add the solutions. For example, you can't add NaCl first because two precipitates will form: AgCl and PbCl2.

[plasticfood]

so in order, they should be like Na2SO4, NaCl, Na2S?

[opti384]

Hm... This is a bit strange. To my humble knowledge, Ag2SO4 and PbSO4 are both precipitates. PbS and NiS are also precipitates.

[Borek]

PbCl₂ dissolves in hot solutions.

[plasticfood]

according to my solubility rules, pbcl2 is only slightly soluble, what would i do with that?? 

[Borek]

Heat the solution up, AgCl stays solid, lead chloride dissolves.

[plasticfood]

that doesn't apply to the problem...

[Borek]

Yes it does, filter the hot solution and you have separated AgCl.