[Enola]

Hi.

I have a problem. I conducted a reaction in the laboratory: to Na₂S(aq) I added CH₃COOH (high concetration) and then Pb(CH₃COO)₂. But instead of black sediment I got white. And I'm not sure why. Any ideas?

[ACETAT]

Are you sure you added lead acetate and not zinc acetate?
Other possibility could be caused by the acetic acid, what happens if you  decrease the pH to much .

[Enola]

I'm absolutely sure.
The experiment was actually like this: in the test tube no 1 put egg white, add 30% NaOH, then add CH₃COOH (high concetration) and Pb(CH₃COO)₂ - here I got black sediment.
In the test tube no 2 put Na₂S(aq), add CH₃COOH (high concetration) and then Pb(CH₃COO)₂ - here I got white sediment.

My friend did the same experiment and she got the same results.

[Borek]

to Na₂S(aq) I added CH₃COOH (high concetration)

It should stink as hell. Did it?

My bet is what you were given as Na₂S was actually not sulfide. Sulfate perhaps? That would fit the white color of the precipitate.

[Enola]

to Na₂S(aq) I added CH₃COOH (high concetration)

It should stink as hell. Did it?

Not at all - that also surprised me.