Chemical equilibrium system and where my ions went

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Discussion Overview

The discussion revolves around the chemical equilibrium involving H+ ions in a mixture containing BaCrO4(s) and CrO42-. Participants explore the reactions that occur when HCl is added to a solution of K2CrO4 and NaOH, as well as the resulting changes in the solution's color and composition.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant asks about the effects of adding H+ to the mixture and proposes that K2CrO7 is formed, indicated by the orange color of the solution.
  • Another participant provides the Ksp values for barium hydroxide and barium chromate, potentially to inform the solubility dynamics in the reaction.
  • A participant reflects on their earlier misidentification of barium chromate and revises their reaction equation to include HCl reacting with BaCrO4.
  • One participant challenges the proposed equilibrium equation, suggesting that the presence of H+ would lead to the formation of water instead of OH-.
  • The same participant concludes that this adjustment clarifies the fate of H+ ions in the reaction.
  • Another participant suggests starting a new thread for further questions on the topic for clarity.

Areas of Agreement / Disagreement

Participants express differing views on the chemical reactions and products formed in the presence of H+ ions, indicating that the discussion remains unresolved regarding the exact nature of the equilibrium and the products formed.

Contextual Notes

Participants reference Ksp values and the behavior of ions in solution, but there are unresolved assumptions regarding the precipitate and the overall reaction dynamics.

allywallyrus
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sorry if this has been asked before, i did a search and couldn't find any results.
Explain fully what happens when H^+ is added to a mixture containing BaCrO_4(s) and CrO_4^2^-.

The overall equation of ions in this experiment is H^+(aq)~+~2CrO_4^2^-\rightleftharpoons~Cr_2O_7^2^-(aq)~+~OH^-(aq)

when HCl is added to a solution of K2CrO4 and NaOH and Ba(NO3)2, the precipitate dissolves and the solution becomes orange. I am pretty stumped, but I am assuming K2CrO7 is present because it is orange in colour and that the precipitate from before becomes aqueous again but I am not sure what the percipitate is (possibly Ba(OH)2??) or what is involved in the reaction. any push in the right direction is very appreciated!
 
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Ksp of barium hydroxide is 5 X 10-3 and the Ksp of barium chromate is 2.2 X 10-10.

Hope it helps.
 
chemisttree said:
Ksp of barium hydroxide is 5 X 10-3 and the Ksp of barium chromate is 2.2 X 10-10.

Hope it helps.

i just realized i even identified barium chromate as a solid in my first post, hahaha :P
thank you anyway

so now my equation is looking more like HCl(aq) + BaCrO4 -> Cr2O7 + BaCl(aq) + H+
 
allywallyrus said:
H^+(aq)~+~2CrO_4^2^-\rightleftharpoons~Cr_2O_7^2^-(aq)~+~OH^-(aq)

It won't work this way. Think what will happen to produced OH- in the presence of H+.
 
Borek said:
It won't work this way. Think what will happen to produced OH- in the presence of H+.

so we'd have H2O in the products instead, which makes more sense because this also balances nicely as well
i think this clears up where H+ ions were going, thanks :)

i don't suppose it would be a problem if i recycled this thread for questions on the same subject? i will probably have some more
 
No, you better start a new thread. Give it more informative subject.
 
alright, thanks again
 

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