1. The correct net ionic equation for the dissolution of solid PbCrO4 in water is:
PbCrO4(s) -> Pb2+(aq) + CrO4^2-(aq)
It is an equilibrium equation.
2. The equilibrium constant expression for this reaction is:
Ksp = [Pb2+][CrO4^2-]
Your thoughts are correct.
3. To increase the solubility of the PbCrO4, you can add a strong acid like HCl.
Your thoughts are correct.
4. The equations to describe how the added reagent (HCl) works to increase the PbCrO4 solubility are:
HCl(aq) + CrO4^2-(aq) -> HCrO4^-(aq) + Cl^-(aq)
PbCrO4(s) + 2HCl(aq) -> Pb2+(aq) + 2Cl^-(aq) + H2CrO4(aq)
5. To decrease the concentration of Pb2+ in solution, you can add Ba(OH)2, just as you thought. This is because the Pb2+ will react with the OH- to form Pb(OH)2, which will precipitate:
Pb2+(aq) + 2OH^-(aq) -> Pb(OH)2(s)
Hey guys! Stuck on some! My maybe answers are written next to the problem (1 problem-5 parts). Thanks for any help:
1. Lead (II) chromate, PbCrO4, is a slightly soluble salt. Write a net ionic equation for the
dissolution of solid PbCrO4 in water.
My thoughts: PbCrO4+2H+-->2Pb2++CrO72-+H2O
Or is it simply PbCrO4->Pb2++CrO42-
(is this an equilibrium equation???)
Write an equilibrium constant expression for this reaction.
K =
My thoughts: Ksp=[Pb2+][CrO42-]
What might one add to increase the solubility of the PbCrO4? ________________________
My thoughts: A strong acid like HCl
Write equations to describe how this added reagent works to increase the PbCrO4 solubility.
My thoughts: I have no idea, please help!!!!
What reagent could be added to decrease the concentration of Pb2+ in solution?
My thoughts: Ba(OH)2 (?) because the Pb2+ will react with the OH- to form Pb(OH)2, which will leave less Pb2+ ions?
1 answer