92 terms

# Chapter 18

LEGGO
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A small amount of solid calcium hydroxide is shaken vigorously in a test tube almost full of water until no further change occurs and most of the solid settles out. The resulting solution is:
dilute and saturated
The solubility of SrSO4 (Ksp = 7.6 × 10-7) is:
8.7 × 10-4 M
What is the molar solubility of barium carbonate in pure water? (Ksp = 5.1 × 10-9)
7.1 × 10-5 M
A saturated solution of magnesium fluoride has a concentration of 1.17 × 10-3 M. For this compound, Ksp =
4(1.17 × 10-3)3
The solubility of CaF2 is 0.00021 mole per liter. What is the solubility product constant for CaF2?
3.7 × 10-11
The solubility of copper(II) iodate is reported as 0.12 g per 100 mL. What is the solubility product for this salt?
9.8 × 10-8
The solubility of magnesium fluoride in water at 18 °C is tabulated as 0.0076 g per 100 mL. What is the solubility product for this salt?
7.3 × 10-9
The solubility product of Li3PO4 is 3.2 × 10-9. What is the molar solubility of Li3PO4 in water?
3.3 × 10-3 M
The solubility of a salt MX2 with a molar mass of 114 g/mole is 3.42 g/liter. Calculate Ksp.
1.08 × 10-4
The solubility of cerium iodate, Ce(IO3)3, molar mass = 664.83, in pure water is 124 mg per 100 ml of water. Calculate the solubility product constant for cerium iodate.
3.3 × 10-10
A saturated solution of silver iodide has a concentration of 9.1 × 10-9 M. What is the Ksp of this compound?
(9.1 × 10-9)2
The solubility product of silver sulfate is 1.6 × 10-5. What is the molar solubility of this compound?
(16/4)1/3 × 10-2
A saturated solution of silver chromate has a concentration of 7.4 × 10-5 M. What is the Ksp of this compound?
4(7.4 × 10-5)3
The solubility product of silver bromide is 5.0 × 10-13. What is the molar solubility of this compound?
(50)1/2 × 10-7
The solubility of a salt MX2 with a molar mass of 170 . g/mole is 12.7 g/liter. Calculate Ksp.
1.67 × 10-3
Which of the following salts, each of which has a solubility product equal to 1.0 × 10-6, has the greatest molar solubility?
MX3
Which of the following has the largest molar solubility?
Cr(OH)2, Ksp = 6.3 × 10-11
Which of the following is least soluble?
PtS (Ksp = 8 × 10-73)
When solid silver chloride is shaken with a 0.1 molar solution of potassium iodide, most of the silver chloride is converted to silver iodide. This transformation takes place because:
silver iodide is less soluble than silver chloride
Which of the following is most soluble?
MnS (Ksp = 7 × 10-16)
In which solution will AgNO3 be least soluble?
0.01 M HNO3
Which of the following should dissolve the smallest amount of silver sulfide per liter, assuming no complex formation?
0.1 M AgNO3
Which of the following soil additives would best reduce the concentration of dissolved Fe3+ in ground water?
lime [Ca(OH)2]
The solubility product of M2CrO4(s) is 7.11 × 10-15. How many moles of M2CrO4(s) will dissolve in 744 mL of solution in which [CrO42-] = 0.056 M?
1.3 × 10-7 mol
Predict the molar solubility of the following salt in a solution that contains the given concentration of one of its ions:
2.6 × 10-6 M
Predict the molar solubility of the following salt in a solution that contains the given concentration of one of its ions:
1.2 × 10-11
What is the molar solubility of PbI2 (Ksp = 7.1 × 10-9) in 0.10 M Pb(NO3)2?
7.1 × 10-8 M
The Ksp of AgCl is 1.7 × 10-10. How many moles of MnCl2 can be dissolved in one liter of a solution in which [AgNO3] = 3.4 × 10-4 M before a precipitate appears.?
2.5 × 10-7 mol
The solubility product for iron(III) hydroxide at 22 °C is 6.0 × 10-38. What mass of this compound will dissolve in 100 mL of 0.20 M sodium hydroxide, assuming no complex formation?
8 × 10-35 g
There are several factors that limit the accuracy of a Ksp calculation. Which of the following is NOT a limitation on Ksp calculations?
number of digits in a calculator
Which of the following does NOT favor increased solubility of calcium fluoride?
cooling the solution
Fe(OH)3 is most soluble in which solution?
pure water
When equal volumes of the indicated solutions are mixed, precipitation should occur only for:
2 × 10-4 M Ca2+ + 2 × 10-2 M F-
When equal volumes of the indicated solutions are mixed, precipitation should occur only for:
2 × 10-4 M Ca2+ + 2 × 10-4 M CO32-
When equal volumes of the indicated solutions are mixed, precipitation should occur only for:
2 × 10-3 M Mg2+ + 2 × 10-3 M F-
A homeowner in Boston becomes concerned that there may be appreciable amounts of lead in her drinking water due to 150-year old water pipes in her house. Consequently, she takes a sample of her drinking water in to be analyzed. The laboratory technician, who is new on the job, has been told to analyze by precipitating the lead ion as the iodide (Ksp = 7.1 × 10-9 for PbI2) by slowly adding small portions of 1.00 M NaI solution.

If we assume that the concentration of lead in the solution is 1.00 mg/liter or approximately 4.8 × 10-6 M (this would be 1.0 part per million) is it possible to detect the lead in the drinking water by adding a total of no more than 10.0 ml of NaI solution to a 100 ml sample of drinking water?
yes, Q = 3.6 × 10-8
When 100 mL each of 2.0 × 10-5 M Ca2+ and 2.0 × 10-2 M F- are mixed, what is the remaining Ca2+ ion concentration and is precipitation complete? The solubility product of CaF2 is 5.3 × 10-9.
5.3 × 10-5 no
When 100 mL each of 2.0 × 10-5 M Ca2+ and 2.0 × 10-3 M CO32- are mixed, what is the remaining Ca2+ ion concentration and is precipitation complete? The solubility product of CaCO3 is 2.8 × 10-9.
2.8 × 10-6 no
When 100 mL each of 2.0 × 10-6 M Ag+ and 2.0 × 10-3 M Br- are mixed, what is the remaining Ag+ ion concentration and is precipitation complete? The solubility product of AgBr is 5.0 × 10-13.
5.0 × 10-10 yes
When 100 mL each of 2.0 × 10-4 M Ag+ and 2.0 × 10-1 M CO32- are mixed, what is the remaining Ag+ ion concentration and is precipitation complete? The solubility product of Ag2CO3 is 8.5 × 10-12.
9.2 × 10-5 no
When 0.10 M NaF is added slowly to a solution that is 0.025 M Ba2+ and 0.025 M Ca2+, what will be the concentration of calcium when barium just begins to precipitate? Ksp barium fluoride 1.0 × 1-7; Ksp calcium fluoride 1.7 × 10-10
4.3 × 10-5 M
Consider an aqueous solution which is 0.020 M in Pb2+ and 0.20 M in Ag+. Concentrated potassium iodide solution (so that volume changes may be neglected) is added gradually with good stirring to this solution. Eventually the iodide ion concentration should increase enough to cause precipitation of the second ion. What will be the concentration of the first ion left in solution when the second ion just begins to precipitate?
1.4 × 10-13 M
A solution contains [Ba2+] = 5.0 × 10-5 M, [Ag+] = 3.0 × 10-5 M, and [Zn2+] = 2.0 × 10-7 M. Sodium oxalate is slowly added so that [C2O42-] increases. What is the concentration of the first cation to precipitate when the second cation just begins to precipitate?
2.2 × 10-6
To a saturated solution of barium carbonate is added just enough sodium sulfate to achieve a maximum sulfate concentration without precipitation of barium sulfate. If no complexes form and the "salt effect" is negligible, what is the concentration of the sulfate ion in this solution? [Ksp for barium carbonate is 1.6 × 10-9; Ksp for barium sulfate is 7.9 × 10-11]
2.0 × 10-6 M
In which of the following one molar solutions would you expect cadmium sulfide, CdS, to be the most soluble?
HCl
The solubility product constant of Mg(OH)2 is 9.0 × 10-12. If a solution is 0.010 M with respect to Mg2+ ion, the amount of [OH-] required to start the precipitation of Mg(OH)2 is:
3.0 × 10-5 M
To a concentrated buffer of pH 9.0 was added an equal volume of a solution that was 0.20 M in each of the ions Ca2+, Cd2+, and Cu2+. The expected precipitate would consist of:
only Cd(OH)2 and Cu(OH)2
If iron(III) acetate is added to be 1 × 10-10 M in a solution that is 0.10 M NH3, what is Qsp and will Fe(OH)3 precitate? The Ksp of Fe(OH)3 is 4 × 10-38 and Kb for NH3 is 1.8 × 10-5.
2.4 × 10-19 yes
If chromium(III) chloride is added to be 1 × 10-12 M in a solution that is 0.10 M NH3, what is Qsp and will Cr(OH)3 precitate? The Ksp of Cr(OH)3 is 6.3 × 10-31 and Kb for NH3 is 1.8 × 10-5.
2.4 × 10-21 yes
What is the free Zn2+ concentration if 0.020 M Zn2+ solution is mixed with an equal volume of 2.0 M NH3? Kf for [Zn(NH3)4]2+ is 4.1 × 108
2.9 × 10-11
What is the free Cu2+ concentration if 0.020 M Cu2+ solution is mixed with an equal volume of 4.0 M NH3? Kf for [Cu(NH3)4]2+ is 1.1 × 1013
1.4 × 10-15
What is the free Ag+ concentration of 0.020 M Ag+ solution mixed with an equal volume of 2.0 M NH3? Kf for [Ag(NH3)2]+ is 1.6 × 107.
6.4 × 10-10
What is the approximate concentration of free Fe3+ ion in a solution prepared by mixing equal volumes of 0.06 M Fe3+ and 4.0 M F- solutions? [The net formation constant for FeF5(H2O)2- is 2.0 × 1015.]
6.0 × 10-19 M
In which of the following solutions will the concentration of dissolved silver species be the highest if solid AgNO3 is stirred with 1.00 L of solution?
1.00 M NH3(aq)
Equal volumes of a 0.020 M Zn2+ solution and a 2.0 M NH3 solution are mixed. Kf for [Zn(NH3)4]2+ is 4.1 × 108. If enough sodium oxalate is added to make the solution 0.10 M in oxalate, will ZnC2O4 precipitate. Ksp ZnC2O4 = 2.7 × 10-8
no, Q = 2.9 × 10-12
Equal volumes of 0.020 M Ag+ solution and 2.0 M NH3 solution are mixed. Kf for [Ag(NH3)2]+ is 1.6 × 107. If trisodium arsenate is added so that the arsenate ion concentration is 0.10 M, will silver arsenate precipitate?
Ksp for silver arsenate is 1.0 × 10-22.
no, Q = 2.6 × 10-29
What is the minimum concentration of CN- that will prevent the precipitation of AgX(s) from a solution that is 0.149 M in X-(aq) and 0.0184 M in Ag+(aq)? (Ksp for AgX(s) = 5.2 × 10-17; Kf for Ag(CN)2- = 5.6 × 1018)
3.1 × 10-3 M
Choose the compound which is most soluble in water.
K2S
What is the composition of the precipitate formed when H2S gas is bubbled through a solution of 0.010 M Zn2+, 0.010 M Pb2+, and 0.010 M Mn2+, buffered at pH 2.0, until 0.10 mol of H2S has been added? [Ksp values are: ZnS: 1.6 × 10-23; MnS: 7.0 × 10-16; PbS: 7.0 × 10-29. For H2S, Ka1 = 1.0 × 10-7; Ka2 = 1.3 × 10-13.
only ZnS and PbS
Write the solubility product constant for KAl(SO4)2(s)?
([K+] × [Al3+] × [SO42-]2)
Write the solubility product expression for the following salt: Na2CO3
[Na+]2[CO32-]
Write the solubility product expression for the following salt: Ca(OH)2
[Ca2+][OH-]2
Write the solubility product expression for the following salt: PbC2O4
[Pb2+][C2O42-]
Write the solubility product expression for the following salt: Ag2SO4
[Ag+]2[SO42-]
Write the solubility product expression for the following salt: Ca3(PO4)2
[Ca2+]3[PO43-]2
Write the solubility product expression for the following salt: CoS
[Co2+][S2-]
At a temperature for which the solubility product of calcium carbonate is 4.7 × 10-9, what mass of the salt will dissolve in 100 mL of water?
0.69 mg
The following table lists five compounds and their Ksp value. Which is least soluble?
AgCl
What is the concentration of Ca2+ in ppm (mg/L) in cave water saturated with calcite (calcium carbonate, Ksp = 4.7 × 10-9)?
5.0
The molar solubility of calcium phosphate in a saturated aqueous solution of the salt is given by:
(Ksp)1/2
The relationship between the molar concentration of silver ion in a saturated solution of silver phosphate and the solubility product for silver phosphate is:
Ksp = 0.333[Ag+]4
What molar concentration of silver ion could exist in a solution in which the concentration of CrO42- is 1.0 × 10-4 M? (Ksp of Ag2CrO4 = 1.1 × 10-12)
1.0 × 10-4
When 200 mL of 0.10 M BaCl2 is added to 100 mL of 0.30 M Na2SO4, the number of moles of BaSO4 (solubility product = 1.1 × 10-10) precipitated is:
0.020
The solubility product of PbI2 is 7.1 × 10-9. How many moles of PbI2 will precipitate if 250 ml of a 0.200 M solution of NaI are added to 150 ml of 0.100 M solution of Pb(NO3)2? You may neglect hydrolysis.
0.015 mol
A concentrated buffer of pH 8.0 is added to an equal volume of a solution that is 0.080 M in each of the ions Zn2+, Ni2+, and Mn2+. The expected precipitate would consist of:
Ni(OH)2 and Zn(OH)2
Consider an aqueous solution which is 0.020 M in Pb2+ and 0.20 M in Ag+. If concentrated potassium iodide solution (so that volume changes may be neglected) is added gradually with good stirring to this solution, which precipitate will form first?
AgI
To a concentrated buffer of pH 4.0 is added an equal volume of a solution that is 0.020 M in Cr3+, Cd2+ and Al3+. The expected precipitate would consist of:
Al(OH)3
A swimming pool was sufficiently alkaline so that the carbon dioxide absorbed from the air produced a solution in the pool that was 2 × 10-4 M in carbonate ion. If the pool originally contained 4 × 10-3 M Mg2+, 6 × 10-4 M Ca2+, and 8 × 10-7 M Fe2+, then the precipitate that was formed consisted of: [Ksp values are: CaCO3, 4.7 × 10-9; MgCO3, 4.0 × 10-5; FeCO3, 2.0 × 10-11]
only CaCO3 and FeCO3
A solution contains [Ba2+] = 5.0 × 10-5 M, [Ag+] = 3.0 × 10-5 M, and [Zn2+] = 2.0 × 10-7 M. Sodium oxalate is slowly added so that [C2O42-] increases.
BaC2O4
What ratio of [NH4+]/[NH3] would provide a buffer of pH low enough to avoid precipitation of Co(OH)2 [Ksp = 2.0 × 10-14] from a 0.50 M Co2+ solution? [Kb for NH3 = 1.8 × 10-5]
100/1
What is the minimum pH at which cobalt(II) hydroxide [Ksp = 2.0 × 10-16] will precipitate from a solution 0.020 M in CO2+?
7.0
Concentrated solutions of sodium sulfate, ammonium carbonate, and nickel (II) nitrate are mixed together. The precipitate which forms is:
nickel (II) carbonate
Concentrated solutions of iron (III) chloride, sodium hydroxide, and potassium nitrate are mixed together. The precipitate which forms is:
iron (III) hydroxide
Concentrated solutions of copper (I) nitrate, sodium sulfate and silver acetate are mixed together. The precipitate which forms is:
silver sulfate
1.00 M solutions of silver nitrate, ammonium chlorate, and sodium acetate are mixed together. The precipitate which forms is:
nothing precipitates
Concentrated solutions of cesium iodide, mercury (I) acetate and calcium chlorate are mixed together. The precipitate which forms is:
mercury (I) iodide
Saturated solutions of sodium sulfate, ammonium carbonate, and nickel (II) nitrate are mixed together. The precipitate that forms is:
nickel (II) carbonate
In a qualitative cation analysis, the unknown ion is precipitated by HCl, remains as a chloride solid in hot water, and the precipitate turns black upon addition of ammonia. The unknown ion is
Hg2^2+
In a qualitative cation analysis, the unknown ion is unaffected by HCl, but is precipitated by hydrogen sulfide. The unknown ion is
Cu2+
In a qualitative cation analysis, the unknown ion is not precipitated by HCl or H2S, but is precipitated by CO32-. The unknown ion is
Ca2+
In a qualitative cation analysis, the unknown ion is not precipitated by HCl, H2S, or CO32-. A flame test produced a violet flame. The unknown ion is
K+
Choose the INCORRECT statement.
If ΔG = 0, the process is spontaneous.