CHM 151(cont.) 8. From each of the following ion concentrations in a solution, p

Question

CHM 151(cont.)

8.         From each of the following ion concentrations in a solution, predict whether a precipitate will form in the solution.

a.)        [Mg2+] = 0.0065 M, [CO32-] = 0.0058 M

Ksp = 3.5 x 10-8

b.)        [Ag+] = 0.046 M, [SO42-] = 0.0055 M

Ksp = 1.4 x 10-5

9.         How many moles of calcium chloride can be added to 0.80L of 0.012 M K2CO3 before a precipitate is expected? Assume that the volume of the solution is not changed significantly by the addition of calcium chloride.

10.       Calculate the solubility (in grams per liter) of Zinc hydroxide, Zn(OH)2, in pure water.

Explanation / Answer

if Qsp(ionicproduct) > Ksp(solubility product) precipitation occurs.

so that,

8.

a. Qsp = 0.0065*0.0058 = 3.77*10^-5

   qsp > ksp precipitation occurs.

b. qsp = 0.046^2*0.0055 = 1.164*10^-5

qsp < ksp precipitation donot occurs

9. ksp of Caco3 = 3.36*10^-9

ksp = s^2 = 3.36*10^-9

solubility = 5.8*10^-5 M

solubility PER 0.8 L = 5.8*10^-5*0.8 = 4.64*10^-5 mol

so that

No of mol of CaCl2 can be added = 4.64*10^-5 mol

10. ksp of Zn(OH)2 = 3*10^-17

3*10^-17 = 4S^3    

solubility = 1.96*10^-6 M

in g/L =   1.96*10^-6*99.424 = 1.95*10^-4 g/L

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.