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At a certain temperature* (probably not 25 ºC), the solubility of silver sulfate, Ag2SO4, is 0.010 mol/L. Calculate its solubility product constant for this temperature. 4 SIG. FIG. (required because number is small)
*Solubility product constants are very temperature sensitive. They are generally reported at 25 ºC. Not necessarily using this temperature allows me some flexibility.
Ag2SO4 --------> 2 Ag+ + SO4-
Ksp = (2s)^2(s)
= 4s^3= 4(0.01)^3 = 4e-6
At a certain temperature, the solubility of potassium iodate, KIO3, is 38.6 g/L. Calculate its solubility product constant for this temperature.
S= 38.6 g/L = 1 mol/ 214.001 g = 0.18037 mol/L
KIO3 --------> K+ + IO3-
Ksp= (s)(s) = s^2 = 0.18037^2+0.0325
At a certain temperature, the solubility of cadmium fluoride, CdF2, is 0.083 mol/L. Calculate its solubility product constant for this temperature.
CdF2 --------> Cd (2+) + 2F(-)
Ksp = (Cd(2+))(2F(-))^2
=(s)(4s^2)= 4s^3 = 4(0.083^3) =0.002287
At a certain temperature, the solubility product constant* of copper (II) iodate, Cu(IO3)2, is 7.60x10-8 M3. Calculate the solubility of this compound for this temperature.
*Unless stated otherwise all solubility product constants are for water.
Cu(IO3)2 --------> Cu(2+) + 2IO3(-)
Calculate the solubility of copper (II) iodate in 0.61 M copper (II) nitrate. Ksp* is 7.4x10-8 M3.
*You should know that the Ksp must refer to the copper iodate because all nitrate compounds are soluble and strong electrolytes!
Cu(IO3)2 --------> Cu(2+) + 2IO3(-)
Warm UP Question. What is the initial (before any reaction takes place) lead nitrate concentration when 5.0 mL of 0.247 M lead nitrate is added to 15 mL of 0.0028 M sodium chloride?
(0.005L)(0.247)= 0.001235 mols lead nitrate/ (0.005 + 0.015) L
[ ]= 0.06175 M
For the reaction: PbCl2(s) ↔ Pb2+(aq)+2Cl1-(aq), what is Q* when 2.4 mL of 0.098 M lead nitrate is added to 20 mL of 0.019 M sodium chloride?
Ksp of lead chloride is 1.6 x 10-5 M3.
Hint given in general feedback
*Recall: Q is compared to Ksp to determine whether a precipitate forms.
Remember each solution is diluted by the other solution.
PbCl2 (s) -------> Pb(2+) + 2Cl-
=(0.0024 L(0.098 M)/ (0.0024+0.02)L) * (0.02(0.019)/(0.0024+0.02)L)^2
Does a precipitate form for the above conditions?
Pick the correct formula for sodium phosphate, calcium phosphate, and aluminum phosphate. (All must be correct to get credit.)
Select one or more:
The Ksp of aluminum phosphate is 9.8x10-21 M2.
The Ksp of calcium phosphate is 1.3x10-32 M5.
Sodium phosphate is added to a solution that contains aluminum nitrate and calcium chloride. Their concentrations, which are necessary to do this problem, are given in the next question. Which begins to precipitate first?
AlPO4 --------> Al(3+) + PO4(3-)
Ksp = 0.0099 [PO4(3-)]
9.8e-21/0.0099 = [PO4(3-)]
Ca3(PO4)2 --------> 3Ca(2+) + 2PO4(3-)
Ksp= ((0.021)^3 [PO4(3-)]^2
the smaller concentration will precipitate first.... aka aluminum phosphate
Sodium phosphate is added to a solution that contains 0.0099 M aluminum nitrate and 0.021 M calcium chloride. The concentration of the first ion to precipitate (either Al3+ or Ca2+) decreases as its precipitate forms. What is the concentration of this ion when the second ion begins to precipitate?
Note that well over 99% of the first ion has precipitated before the second ion starts to precipitate.
Ksp = [Al(3+)][PO4(3-)]