[govibe]

Solutions of EDTA4 - are used to treat heavy metal poisoning by removing the heavy metal in the form of a soluble complex ion. The complex ion virtually eliminates the heavy metal ions from reacting with biochemical systems. The reaction of EDTA4 - with Pb2+ is given below.

Pb2+(aq) + EDTA4 -(aq) -> PbEDTA2-(aq)        K = 1.1 1018
Consider a solution with 0.010 mol Pb(NO3)2 added to 1.0 L of an aqueous solution buffered at pH = 13.00 and containing 0.050 M Na4EDTA. Does Pb(OH)2 precipitate from this solution? Calculate the Ksp and Q

Can anyone help me get started with this problem? (suggestions) because I do not have any idea where to begin

[Borek]

Calculate concentrations of Pb²⁺ and OH^- from given data, put them into Ksp formula.

[govibe]

how do you calculate it? stoichiometry? equilibrium?

[Borek]

how do you calculate it? stoichiometry? equilibrium?

OH is (almost) given. Pb²⁺ can be found assuming EDTA/PbEDTA concentrations are given by complexation reaction stoichiometry and then using stability constant.

[govibe]

So I can find out the OH- concentration from Ph? How does OH- come into this? what stoichiometry do I have to do first? Is the Ksp for the Pb(OH)- or Na4EDTA?

[Borek]

So I can find out the OH- concentration from Ph?

http://www.chembuddy.com/?left=pH-calculation&right=water-ion-product

http://www.chembuddy.com/?left=pH-calculation&right=introduction-acid-base-equilibrium

Sorry, but you are asking questions that clearly show you have completely no idea about what you are asked to do. These are not things that can be explained in a few short posts.