Solubility Combining Ionic Equations,

[Maharg]

Homework Statement

Consider the following equilibria at T = 26 0C, in which all ions are aqueous:
Ag+(aq) + Cl-(aq) ----> AgCl(aq) K1 = 2.0E2
AgCl(s) ----> Ag+(aq) + Cl-(aq) K2 = 1.9E-10

Consider the reaction
AgCl(s) ----> AgCl(aq)


and calculate the concentration of AgCl(aq) in equilibrium with excess undissolved solid AgCl(s).


Hint: calculate K3 first and use the equilibration constant expression to find the concentration of AgCl(aq).

Homework Equations

Ksp = [AgCl] I thinK?

The Attempt at a Solution

So I think I'm on the right track but missing something

To get k3 is just combining k1 and k2, Since they easily cancel out to make AgCl(s) -> AgCl (aq), I think k3 is just 200 + 1.9E-10 = 200

k3 = 200? That seems odd but then even if that is true I'm not sure which is next as with solubility I've always had problems where it is Ksp=[A], but this one is just Ksp=[A] as solids wouldn't count right?

 

[Borek]

Homework Equations

Ksp = [AgCl] I thinK?

No. First, try to write corect formulas for both Kso and complex formation. Just as if there were no other reactions.

 

[Maharg]

Oh I was thinking about it wrong.

Is this correct?

Ag+ + Cl- -> AgCl(aq) k1 = [AgCl]/[Ag+][Cl-]= 2E2
AgCl(s) -> Ag+ + Cl- k2 = [Ag+][Cl-] = 1.9E-10

K3 = k1 k2 = [AgCl(aq)] = 3.8E-8

AgCl(aq) = 3.8E-8 mol/L ?

The last part is only thing I'm not sure about.

 

[Borek]

Kso*Kf, looks OK to me.

 

[Maharg]

Yes thank you it was right. I appreciate the help.