A solution is 0.0100 M in each of the metal ions in the following table:

Follow
  • Follow publicly
  • Follow privately
  • Unfollow
Metal sulfide, Kspa FeS, Kspa = 6 x 10^2 NiS, Kspa = 8 x 10^(-1) PbS, Kspa = 3 x 10^(-7) CuS, Kspa = 6 x 10^(-16) HCl is added to the solution so that the H3O concentration ...show more
Best AnswerAsker's Choice
In saturated solution the ion concentrations satisfy the equilibrium
Ksp = [X²⁺] ∙[S²⁻]
with X = Fe, Ni, Pb or Cu
The sulfide is set to 0.1M. So the maximum metal ion concentration, for which no sulfide precipitates is:
[X²⁺] = Ksp/[S²⁻]
If this concentration is lower than the 0.01M, which are present in solution, the metal sulfide precipitates.

[Fe²⁺] = 6×10²/0.1 = 6×10³M > 0.01M => no precipitate
[Ni²⁺] = 8×10⁻¹ / 0.1 = 8M > 0.01M => no precipitate
[Pb²⁺] = 6×10⁻⁷/0.1 = 6×10⁻⁶M < PbS preciptates
[Cu²⁺] = 6×10⁻¹⁶/0.1 = 6×10⁻¹⁵M < 0.01M => CuS precipitates

Asker's rating & comment

5 out of 5
poster is absolutely correct :)
thank you very much
  • 7
  • Comment
Sign In 

to add your answer

No other answers

Who is following this question?

    %
    BEST ANSWERS
    Member Since:
    Points: Points: Level
    Total Answers:
    Points this week:
    Follow
     
    Unfollow
     
    Block
     
    Unblock