Chemistry

posted by .

Consider a solution that is 0.022 M in Fe^2+ and 0.014 in Mg^2+

A) if K2CO3 is to selectively precipitate one of the cations while leaving the other cation in solution, which cation will precipitate first?

B) What minimum concentration of K2CO3 is required to cause the precipitate of the cation that precipitates first?

C) What is the remaining concentration of the cation that precipitates first, when the other cation just began to precipitate.

Show all your work and calculations,

• Chemistry -

I'll get you started with #1. Look the Ksp values for FeCO3 and MgCO3.

Ksp FeCO3 = (Fe^2+)(CO3^2-)
Plug in Ksp and Fe^2+ from the problem and solve for (CO3^2-).

Then Ksp MgCO3 = (Mg^2+)(CO3^2-)
Plug in Ksp and Mg^2+ from the problem and solve for (CO3^2-)

Now you take these two solns (Fe and Mg solutions) and start adding VERY slowly to each beaker which will start precipitating first. Of course it will be the one which gets to the (CO3^2-) needed FIRST. Which one is that? You have Ksp and the calculations so you can answer that.

• Chemistry -

Okay, I calculated that it should be Fe^2+ that precipitates out first and the concentration of CO3^2- is 9.55x10^-10. is that correct?
in regards to question b: where is K2CO3 coming from? how am I using that in the calculation?

Similar Questions

1. Chemistry

The experiment that I did in lab consisted of performing a qualitative analysis of group 1 and 2 cations and anions. The first thing that I did was to add 5 drops of 3M HCl, centrifuge it, and to observe whether a precipitate would …
2. Chemistry

2. what solution can you add to each of the following cation mixtures to precipitate one cation while keeping the other cation in sloution?
3. Chemistry

You are given an unknown solution that only contains one of the two listed cations. Describe a simple test to distinguish between aqueous solutions of the following cations. State the distinguishing outcomes of the test and the indication …
4. Chemistry!!!

Consider a solution that is 0.022 M in Fe2+ and 0.014 M in Mg+2. A). If potassium carbonate is used to selectively precipitate one of the cations while leaving the other on solution, which cation will precipitate first?
5. chemistry-urgent

Silver nitrate is added to a solution and precipitate forms. This precipitate dissolves when concentrated ammonia is added. What anion was present in the original solution?
6. Chemistry 1010

How many grams of Ag2CO3 will precipitate when excess K2CO3 solution is added to 70.0 mL of 0.692 M AgNO3 solution?
7. Chemistry

Consider this reaction: 3 K2CO3 (aq) + 2 CrCl3 (aq) -> Cr2(CO3)3 (s) + 6 KCl (aq) If 1.2 moles of CrCl3 react, how many moles of K2CO3 will react with it?
8. Chemistry

What mass of calcium citrate, Ca3(C6 H5 O7)2, would a tablet manufacturer need to use to provide the same amount of Ca that you found in your tablet?
9. Chemistry

In the qualitative analysis scheme, magnesium and nickel precipitate from solution upon the addition of sodium hydroxide. Once separated from the remaining cations by filtration or decanting, the solid mixture is acidified and warmed …