Name:______Answer Key_________________________________________AP Chemistry Review Quiz
Topic 3: Solutions
__B___1. Which of the following aqueous solutions has the highest boiling point?
(A) 0.5 m NaCl (B) 0.5 m CaCl2
(C) 0.5 m KBr (D) 0.5 m C6H12O6
(E) 0.5 m NaNO3
__E___2. The bottler of a carbonated beverage dissolves carbon dioxide in water by placing carbon
dioxide in contact with water at a pressure of 1 atm at room temperature. The best way to
increase the amount of dissolved CO2 would be to
(A)
(B)
(C)
(D)
(E)
Increase the temperature without changing the pressure of CO2
Increase the pressure of CO2 without changing the temperature
Increase the temperature and increase the pressure of CO2
Decrease the temperature and decrease the pressure of CO2
Decrease the temperature and increase the pressure of CO2
__E___3. If the solubility of BaF2 is equal to x, which of the following expressions is equal to the
solubility product, Ksp, for BaF2?
(A) x2
(B) 2x2
(C) x3
(D) 2x3
(E) 4x3
__D___4. A student added 0.10 mol of NaBr and 0.20 mol of BaBr2 to 2 liters of water to create an
aqueous solution. What is the minimum number of moles of Ag(C2H3O2) that the student must
add to the solution to precipitate out all of the Br- ions as AgBr?
(A) 0.20
(B) 0.30
(C) 0.40
(D) 0.50
(E) 1.00
__Skip___5. Copper (II) chloride will be least soluble in a 0.02-molar solution of which of the following
compounds?
(A) NaCl
(B) CuNO3
(C) CaCl2
(D) NaCO3
(E) KI
__E___6. The molar solubility of PbS in water is 3 × 10-14 M. What is the solubility product constant, Ksp,
for PbS?
(A) 2 × 10-7
(B) 9 × 10-7
(C) 3 × 10-14
(D) 3 × 10-14
(E) 9 × 10-28
__E___7. If 87 grams of K2SO4 (molar mass 174 grams) is dissolved in enough water to make 250 milliliters of
solution, what are the concentrations of the potassium and the sulfate ions?
[K+]
(A)
(B)
(C)
(D)
0.020 M
1.0 M
2.0 M
2.0 M
(E) 4.0 M
[SO42−]
0.020 M
2.0 M
1.0 M
2.0 M
2.0 M
1. The value of the solubility product, Ksp, for calcium hydroxide, Ca(OH)2, is 5.5 × 10-6, at 25°C.
(a) Write the Ksp expression for calcium hydroxide.
Ksp = [Ca2+][OH-]2
(b) What is the molar solubility of Ca(OH)2 in 500. ml of a saturated solution at 25°C?
R
I
C
E
Ca(OH)2 (s)↔
--------------------------------------------------
Ca2+ + 2OH0M
0M
+x
+2x
x
2x
Ksp = [Ca2+][OH-]2
5.5 × 10-6 = (x)(2x)2
5.5 x 10-6 = 4x3
X = 0.011M
Molar solubility = 0.011M
(c) What is the pH of the solution in (b)?
[OH-] = 2x = 0.022M
pOH = -log [OH-] = -log(0.022M)
pOH = 1.66
pH = 14- pOH = 14-1.
pH =12.34
(d) i. If 1.0 mole of OH- is added to the solution in (b), will the solubility of Ca(OH)2 increase ,
decrease or remain the same. Justify your answer.
The addition of a common ion will cause an increase in the speed of the reverse reaction. The
solubility of Ca(OH)2 will decrease and more precipitate will form.
ii.
R
I
C
E
What will be the resulting Ca2+ concentration? Assume that the volume of the solution
does not change.
Ca(OH)2 (s)↔
--------------------------------------------------
Ca2+ + 2OH0M
2M
+x
+2x
x
2M + 2X
Ksp << [OH-]I
[OH-]I ≈ [OH-]E
Ksp = [Ca2+][OH-]2
5.5 × 10-6 = (x)(2M)2
5.5 x 10-6 = 4X
X = 1.375 x 10-6 M
[Ca2+] = 1.375 x 10-6 M
2. Write the molecular equation, complete ionic equation and net ionic equation for the following
reaction.
A solution of sodium carbonate is combined with a solution of iron(III) nitrate.
Molecular Equation:
3 Na2CO3 (aq) + 2 Fe(NO3)3 (aq) → 6 NaNO3 (aq) + Fe3(CO3)2 (s)
Detailed Ionic:
6 Na+ + 3CO32- + 2Fe3+ + 6 NO3- → 6 Na+ + 6NO3- +
Net Ionic Equation:
3CO32- + 2Fe3+ → Fe3(CO3)2 (s)
Fe3(CO3)2 (s)
3. Answer the questions below that relate to the five aqueous solutions at 25ºC shown below.
(a) Which solution has the highest boiling point? Explain.
Solution 1 will have the most dissolved particles so it will have the highest boiling point.
(b) Identify a pair of the solutions that would produce a precipitate when mixed together. Write the
formula of the precipitate.
Solutions 1 and 2 will form a precipitate, PbCl2 . Solutions 1 and 3 will as well Pb(KMnO4)2
(c) Which solution would be the least effective conductor of electricity? Explain your choice.
Solution 4 will be the worst conductor because it lacks dissolved ions. (covalent compound)
(d) Which solution contains a neutral salt? Explain your choice.
Solution 2 contains a neutral salt. It is the product of a strong acid and a strong base.
Solution 1 is an acidic salt.
Solution 3 is a basic salt.
Solution 4 is not a salt.
Solution 5 is a basic salt.