[Borek]

1.000 g of a roasted salt decomposes producing three oxides - 0.878 g of a solid one, 0.0354 g of a liquid one and 0.0866 g of a gaseous one (at STP).

Determine the salt identity.

[Rutherford]

I got Pb(OH)₂·PbCO₃ or (PbOH)₂CO₃, not quite sure  .

[Big-Daddy]

(PbOH)₂CO₃,

Surely this can't exist ... That would mean the (PbOH)⁺ ion exists which I doubt.

[Rutherford]

Okay, then maybe the first one.

[Big-Daddy]

Borek when you say oxides do you just mean the salt contains oxygen in some form, or specifically the O^2- ion? (Or can you not tell us?)

[Borek]

Borek when you say oxides do you just mean the salt contains oxygen in some form, or specifically the O^2- ion? (Or can you not tell us?)

No idea what you are asking about. Have you seen gaseous oxide containing O^2-?

[Big-Daddy]

Borek when you say oxides do you just mean the salt contains oxygen in some form, or specifically the O^2- ion? (Or can you not tell us?)

No idea what you are asking about. Have you seen gaseous oxide containing O^2-?

No, but then Raderford is suggesting a carbonate, which I would not normally class as an oxide. So by oxide you mean any salt containing O somewhere?

[Borek]

No, but then Raderford is suggesting a carbonate, which I would not normally class as an oxide. So by oxide you mean any salt containing O somewhere?

Have you read the question?

[Big-Daddy]

No, but then Raderford is suggesting a carbonate, which I would not normally class as an oxide. So by oxide you mean any salt containing O somewhere?

Have you read the question?

  That was stupid of me.

[delta609]

TlHCO3

[delta609]

 I didn't get the exact amounts you have posted, but very close. 

2TlHCO3  Tl₂CO₃ + CO₂ + H₂O
Tl

Tl₂CO₃ = .883g
CO₂ = .083g
H₂O = .034g

[Borek]

Tl₂CO₃ is not an oxide.

[delta609]

Pb₂(OH)₂CO₃

Pb₂(OH)₂CO₃  2PbO + CO₂ + H₂O

numbers are spot on this time.

[Borek]

Raderford was first:

I got Pb(OH)₂·PbCO₃ or (PbOH)₂CO₃, not quite sure  .

No matter how you write it, this is the intended answer.

And I should slap myself again, as I have not checked details. Problem was used in a chemistry competition, and after solving and checking that the numbers are OK I assumed the compound is just a basic lead carbonate. Turns out it is not - so called white lead has a slightly different formula (2PbCO₃·Pb(OH)₂). It doesn't mean Pb(OH)₂·PbCO₃ doesn't exist, as there are several similar compounds, but I prefer problems with the obviously existing real solutions.

[blaisem]

Would anyone mind providing a link or a keyword for google where I can read how a problem like this is approached/solved?

Thank you