Analytical Chemistry - Systematic Treatment of Equilibrum

In summary, we need to calculate the molar solubility of Ag2C2O4 in a solution with a fixed H3O+ concentration of 1.0 x 10^-6 M. To do this, we must first determine the pertinent reactions, which are Ag2C2O4(s) → 2Ag+(aq) + C2O4(2-)(aq), H2C2O4(aq) + H2O(l) → HC2O4-(aq) + H3O+(aq), and HC2O4-(aq) + H2O(l) →C2O4(2-)(aq) + H30+(aq). We also need to consider
  • #1
ahhppull
62
0

Homework Statement



Calculate the molar solubility of Ag2C2O4 (silver oxalate) in a solution that has a fixed H3O+ concentration of 1.0 x 10^-6 M.

Homework Equations





The Attempt at a Solution



I found the pertinent reactions, the charge balance and the mass balance so far, but I don't know what to do next.

Pertinent Reactions
Ag2C2O4(s) → 2Ag+(aq) + C2O4(2-)(aq) Ksp = 5.40 x 10^-12
H2C2O4(aq) + H2O(l) → HC2O4-(aq) + H3O+(aq)
HC2O4-(aq) + H2O(l) →C2O4(2-)(aq) + H30+(aq)

Charge Balance
[Ag+] + [H3O+] = 2[C2O4(2-)] + [HC2O4-]

Mass Balance
[Ag+] = 2[C2O4(2-)]
[Ag+] = 2{[C2O4(2-)] + [HC2O4-] + [H2C2O4]}
 
Physics news on Phys.org
  • #2
What reactions take place, what are equilibrium constants (other than Ksp you already listed) for them?
 
  • #3
I found that Ka1 = 5.60 x 10^-2 and ka2 =5.10 x 10^-5. Another site listed 5.4x10^-2 and 5.4x10^-5.

EDIT: Actually, I finally found it in my textbook. Ka1 = 5.62E-2 and ka2 = 5.42E-5
 
Last edited:
  • #4
Write formulas for both dissociation constants. Count your equations and your unknowns - are you ready to solve?
 
  • #5
Hey Borek, I wrote out all the formulas. My question now is what exactly am I solving for? Am I suppose to solve for all the concentrations? [Ag+], [C2O4(2-)], [HC2O4-] and [H2C2O4]?

Also how am I suppose to solve for Ag+? Is it 5.4E-12 = [2x]^2 [x]?
 
  • #6
Technically you should have a set of n-equations in n-unknowns - yes, solve for all unknowns and you are done.

Easier said than done, these are not linear equations, so you have to look for approximations or go numerical.

ahhppull said:
Also how am I suppose to solve for Ag+? Is it 5.4E-12 = [2x]^2 [x]?

It doesn't make sense to add another unknown x, you already have plenty of unknowns and this one is not going to make the problem much easier.
 

Related to Analytical Chemistry - Systematic Treatment of Equilibrum

1. What is the purpose of analytical chemistry?

The purpose of analytical chemistry is to identify and quantify the chemical components of a sample, as well as to understand the chemical processes that occur within a system. This information can be used to solve practical problems and improve our understanding of natural phenomena.

2. What is equilibrium in analytical chemistry?

Equilibrium in analytical chemistry refers to a state where the rate of a chemical reaction or process is equal to its reverse rate. This means that there is no net change in the concentration of reactants and products, and the system is in a stable state.

3. What is the significance of studying equilibrium in analytical chemistry?

Studying equilibrium in analytical chemistry is important because it allows us to understand the behavior of chemical systems and their components. This knowledge is essential for accurately measuring and interpreting data, as well as for predicting the effects of changing conditions on a system.

4. How is equilibrium represented in analytical chemistry?

Equilibrium in analytical chemistry is typically represented using equilibrium constants, which are ratios of the concentrations of products to reactants at equilibrium. These constants provide a quantitative measure of the extent to which a reaction has reached equilibrium.

5. What factors can affect equilibrium in analytical chemistry?

Several factors can affect equilibrium in analytical chemistry, including temperature, pressure, and concentrations of reactants and products. Changes in these factors can shift the equilibrium position and alter the rate of a chemical reaction or process.

Similar threads

  • Biology and Chemistry Homework Help
Replies
13
Views
6K
Replies
4
Views
2K
  • Biology and Chemistry Homework Help
Replies
16
Views
33K
  • Biology and Chemistry Homework Help
2
Replies
69
Views
8K
  • Biology and Chemistry Homework Help
Replies
2
Views
7K
  • Biology and Chemistry Homework Help
Replies
15
Views
4K
  • Biology and Chemistry Homework Help
Replies
4
Views
3K
  • Biology and Chemistry Homework Help
Replies
4
Views
4K
  • Biology and Chemistry Homework Help
Replies
2
Views
3K
Back
Top