Question

It is of interest to decide if an analytical separation of the metal ions can be...

It is of interest to decide if an analytical separation of the metal ions can be effected by selective precipitation of carbonates from a solution that is 9.11×10-2 M in Cu2+ and 0.100 M in Ca2+.

CaCO3 Ksp = 3.80×10-9
CuCO3 Ksp = 2.50×10-10


To analyze this problem, answer the following questions.

(1) What carbonate concentration is needed to precipitate 99.9% of the metal that forms the least soluble carbonate? __M

(2) When 99.9% of the least soluble carbonate has precipitated, will all of the metal that forms the more soluble carbonate still remain in solution? Yes/No?

(3) What is the upper limit on the carbonate ion concentration if the more soluble compound is not to precipitate? __M

(4) If the [CO32-] is at this upper limit, what percentage of the metal that forms the least soluble carbonate remains in solution? __%

What is the equilibrium Mg2+ concentration when 1.89 L of a 0.162 M magnesium nitrate solution are mixed with 2.04 L of a 0.282 M ammonium carbonate solution?

[Mg2+] = __M

0 0
Add a comment Improve this question Transcribed image text
Answer #1

(1) To solve this we have to take the Kps from least soluble salt, as we can realize the least soluble is CuCO3 , because it has a lower Kps

knowing that Kps = [Cu+2][CO3-2] = 2.50 x10-10

and now we want to precipitate the 99.9% of the Cu, it mean that the 0.1% of Cu will stay in solution, so we calculate the Cu that will stay in solution

[Cu+2] = (0.1/100) * (9.11 x10-2) = 9.11 x10-5 M

then the carbonate needed would be given by [CO3-2] =Kps / [Cu+2]

[CO3-2] = 2.50 x10-10 / 9.11 x10-5 = 2.7442 x10-6

(2) to know if the another coumpound will stay in solution, we could call Q , the product of the concentration of the ions, so we make

Q = [Ca+2][CO3-2] = (0.1) * ( 2.7442 x10-6) = 2.7442 x10-7   

Q > Kps this means it will also precipitate

(3) to know solubility, the upper limit, we make this change [Cu+2] = [CO3-2] = S

so Kps expresion would be

Kps = S2 and this means S = (Kps)1/2 = (2.50 x10-10)1/2 = 1.5811 x10-5

(4) we will use the Kps formula, but now we will calculate  [Cu+2]

this is

[Cu+2] =Kps / [CO3-2]

using the new concentration of cabonate, we get

[Cu+2] = 2.50 x10-10 / 1.5811 x10-5 = 1.5811 x10-5

so we would get (1 - 1.5811 x10-5 /9.11 x10-2) * 100% = 99.98%

(5)

to know the concentration of [Mg+2] , we start calculating the new concentration of all compounds

[Mg(NO3)2] = 1.89 * 0.162 / (1.89 +2.04) = 7.7908 x10-2 M

[(NH4)2CO3] = 2.04 * 0.282 / (2.04 + 1.89) = 0.1464 M

we can notice tha there is only an atom of Mg in every molecule of [Mg(NO3)2] and also onle a molecule of CO3 in every molecule of [(NH4)2CO3], also we know that they will be those that will precipitate, so let's calculate Q as following, using the concentrations calculated and know the presence of the Mg and CO3.

Q = [Mg+2] [CO3-2] = (7.7908 x10-2 ) * ( 0.1464) = 0.01140

The Kps of this salt is 6.82 x10-6 , Q is greater than Kps, it means that in the solution will only stay the solubility that can have the solution, calculated by

S = (Kps)1/2 = (6.82 x10-6 )1/2 = 2.6115 x10-3

Finally we could say that the [MG+2] that will stay in solution will be 2.6115 x10-3 M

Add a comment
Know the answer?
Add Answer to:
It is of interest to decide if an analytical separation of the metal ions can be...
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for? Ask your own homework help question. Our experts will answer your question WITHIN MINUTES for Free.
Similar Homework Help Questions
  • It is of interest to decide if an analytical separation of the metal ions can be...

    It is of interest to decide if an analytical separation of the metal ions can be effected by selective precipitation of carbonates from a solution that is 0.102 M in Cu²+ and 0.110 Min Ni2+ NiCO3 CuCO3 Ksp = 6.60X10-9 K = 2.50X10-10 To analyze this problem, answer the following questions. (1) What carbonate concentration is needed to precipitate 99.9% of the metal that forms the least soluble carbonate? C M (2) When 99.9% of the least soluble carbonate has...

  • It is of interest to decide if an analytical separation of the metal ions can be...

    It is of interest to decide if an analytical separation of the metal ions can be effected by selective precipitation of carbonates from a solution that is 9.59x102 M in Mn2+ and 0.106 M in Ca24 СаСОз Ksp 3.80x10-9 MnCO3 = 1.80x10-11 Kşp To analyze this problem, answer the following questions (1) What carbonate concentration is needed to precipitate 99.9% of the metal that forms the least soluble carbonate? M (2) When 99.9% of the least soluble carbonate has precipitated,...

  • It is of interest to decide if an analytical separation of the metal ions can be...

    It is of interest to decide if an analytical separation of the metal ions can be effected by selective precipitation of carbonates ftrom a solution that is 0.102 M im Cu? and 0.110 M in NP Kp-2.50 10-10 NiCOs Kup-6.60 10 To analyze this problem, answer the following questions (1) What carbonate concentration is needed to precipitate 99 9% of the metal that forms the least soluble carbonate? When 990% of the least sol ble cat nate has precipt ated,...

  • Many metal ions are precipitated from a solution by the sulfide ion. As an example, consider...

    Many metal ions are precipitated from a solution by the sulfide ion. As an example, consider treating a solution of copper(II) sulfate with sodium sulfide solution: CuSO4(aq) + Na2S(aq) → CuS(s) + Na2SO4(aq) What volume of 0.104 M Na2S solution would be required to precipitate all of the copper(II) ion from 13.4 mL of 0.120 M CuSO4 solution? Volume = mL Submit Answer Try Another Version 7 item attempts remaining Generally, only the carbonates of the Group 1 elements and...

  • A solution containing a mixture of metal cations was treated as outlined. 1. Dilute HCl was...

    A solution containing a mixture of metal cations was treated as outlined. 1. Dilute HCl was added and a precipitate formed. The precipitate was filtered off. 2. H,S was bubbled through the acidic solution. Again, a precipitate formed and was filtered off. 3. The pH was raised to about 9 and H,S was again bubbled through the solution. No precipitate formed. 4. Finally, sodium carbonate was added. A precipitate formed and was filtered off. What can be said about the...

  • A solution containing a mixture of metal cations was treated as follows. 1. Dilute HCl was...

    A solution containing a mixture of metal cations was treated as follows. 1. Dilute HCl was added and a precipitate formed. The precipitate was filtered off. 2. H,S was bubbled through the acidic solution. Again, a precipitate formed and was filtered off. 3. The pH was raised to about 9 and H, S was again bubbled through the solution. No precipitate formed. 4. Finally, sodium carbonate was added and no precipitate formed. What can be said about the presence of...

  • Excess solid Na₂CO₃ is added to a solution containing 0.400 M (each) Mg²⁺ and Zn²⁺ ions....

    Excess solid Na₂CO₃ is added to a solution containing 0.400 M (each) Mg²⁺ and Zn²⁺ ions. Ksp for MgCO₃ is 3.50 × 10⁻⁸ and Ksp for ZnCO₃ is 1.00 × 10⁻¹⁰. ZnCO₃, with the smaller Ksp, will be the least soluble and will begin precipitating first. What will be the [Zn²⁺] concentration when MgCO₃ just begins to precipitate? (Assume no volume change upon addition of the solid Na₂CO₃).

  • Ksp = [Ba²+][10,1 2. 10. mL of 0.10 M Ba(NO), is mixed with 10. mL of...

    Ksp = [Ba²+][10,1 2. 10. mL of 0.10 M Ba(NO), is mixed with 10. mL of 0.10 M KIO,, a precipitate forms. for barium a. Which ion will still be present at appreciable concentration in the equilibrium mixture if K iodate is very small? b. What would that concentration be? 3. Lead chloride, PbCly, is slightly soluble with K equal to 1.7 x 10. a. What is the solubility of lead chloride in pure water? b. What would the solubility...

  • 1. In which solution will aluminum hydroxide, Al(OH)3, be least soluble? The solutions are similar except...

    1. In which solution will aluminum hydroxide, Al(OH)3, be least soluble? The solutions are similar except that they have the following pH values: Hint: Common ion effect. Which two ions dictate acidity and basicity? a. 3    b. 7    c. 9    d. 11 2. Potassium perchlorate has a solubility product constant of 10-2. Which is true about the following solution of KClO4: [K+] = 0.01 M, [ClO4 −] = 0.01 M a. Ksp < Q and no precipitation occurs b....

  • Prelab Activity: Electrochemical Cells To determine the solubility product of copper(II) carbonate, CuCO3 , a concentration...

    Prelab Activity: Electrochemical Cells To determine the solubility product of copper(II) carbonate, CuCO3 , a concentration cell as described on pages 71-72 of the lab handout is constructed. The temperature of the Galvanic cell is measured to be 22.5°C, and the cell potential 282 mV (0.282 V). Using this data and Equation 8 in the lab manual, calculate the Ksp for CuCO3 and report your answer with three significant digits. For the Galvanic cell you will construct in PART B,...

ADVERTISEMENT
Free Homework Help App
Download From Google Play
Scan Your Homework
to Get Instant Free Answers
Need Online Homework Help?
Ask a Question
Get Answers For Free
Most questions answered within 3 hours.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT