1. Which combination of factors will affect the rate of the following reaction?

Zn(s)  +  2HCl(aq)  →  ZnCl2(aq)  +  H2(g)

           

A.        Temperature and surface area only

            B.         Temperature and concentration only

            C.        Concentration and surface area only

            D.        Temperature, concentration, and surface area

 

2. Consider the following reaction: 

2MnO4-(aq)  +  5C2O42-  +  16H+(aq)  →  2Mn2+(aq)  +  10CO2(g)  +  8H2O(l)

The rate of decomposition of the oxalate ion is increased by

           

A.        Adding NaOH

            B.         Removing CO2

            C.        Adding a catalyst

            D.        Decreasing the pressure

 

3. An equilibrium system shifts left when the temperature is increased. The forward rate is

           

A.        Exothermic and ∆H is positive.

            B.        Exothermic and ∆H is negative.

            C.        Endothermic and ∆H is positive.

            D.        Endothermic and ∆H is negative.

 

4. The value of the Keq can be changed by

 

            A.        adding a catalyst.

            B.        changing the temperature.

            C.        changing the reactant concentration.

            D.        changing the volume of the container

 

5. Consider the following equilibrium: 2NOCl(g) ⇄ 2NO(g)  +  Cl2(g)

In a 1.0 L container at equilibrium there are 1.0 mol NOCl, 0.70 mol NO and 0.40 mol Cl2. At constant temperature and volume, 0.10 mol NOCl is added. The concentrations in the “new” equilibrium in comparison to the concentrations in the “old” equilibrium are

 

            [NOCl]                        [NO]                            [Cl2]

 

A         new = old                     new = old                     new = old

            B         new > old                    new > old                    new > old

            C         new < old                     new < old                     new > old

            D         new < old                     new > old                     new > old

6. The equation that represents the equilibrium in a saturated solution of Fe2(SO4)3 is

           

A. Fe2(SO4)3(s) ⇄ 3Fe2+(aq) + 2SO43-(aq)

            B. Fe2(SO4)3(s) ⇄ 2Fe2+(aq) + 3SO43-(aq)

            C. Fe2(SO4)3(s) ⇄ 3Fe3+(aq) + 2SO42-(aq)

                D. Fe2(SO4)3(s) ⇄ 2Fe3+(aq) + 3SO42-(aq)

 

7. When equal volumes of 0.20 M K2CrO4 and 0.20 M AgNO3 are mixed, a red precipitate is formed. The net ionic equation for this reaction is

 

            A.        K+(aq)  +  NO3-(aq)  →  KNO3(s)

            B.        2Ag+(aq)  +  CrO42-(aq)  →  Ag2CrO4(s)

            C.        K2CrO4(aq)  +  2AgNO3(aq)  →  Ag2CrO4(s)  +  2KNO3(aq)

            D.        2Ag+(aq)  +  CrO4-(aq)  +  2K+(aq)  +  2NO3-(aq)  →  Ag2CrO4(s)  +  2KNO3(s)

 

8. Which of the following compounds could be used to prepare a 0.20 M solution of hydroxide ion?

 

            A.        KOH

            B.         Fe(OH)3

            C.        Mg(OH)2

                D.        Zn(OH)2

 

9. When 250 mL of 0.36 M Sr(OH)2 are added to 750 mL of water, the resulting ion concentrations are

 

            A.        [Sr2+]  =  0.12 M and  [OH-]  =  0.12 M

            B.         [Sr2+]  =  0.12 M and  [OH-]  =  0.24 M

            C.        [Sr2+]  = 0.090 M and [OH-]  =  0.090 M

            D.        [Sr2+]  = 0.090 M and [OH-]  =  0.180 M

 

10. When equal volumes of 2.0 M Pb(NO3)2 and 2.0 M KCl are mixed,

           

A.        a precipitate forms because the trial ion product < Ksp

            B.        a precipitate forms because the trial ion product > Ksp

            C.        a precipitate does not form because the trial ion product < Ksp

            D.        a precipitate does not form because the trial ion product > Ksp

 

11. Consider the following equilibrium:  AgCl(s)  ⇄  Ag+(aq)  +  Cl-(aq)

When Br-(aq) is added to a saturated solution of AgCl,

           

A.        more AgCl dissolves and its solubility product increases.

            B.         more AgCl precipitates and its solubility product decreases.

            C.        more AgCl dissolves and its solubility product remains constant.

            D.        more AgCl precipitates and its solubility product remains constant.

12. The molar solubility of iron II sulphide is

 

            A.        3.6  x  10-37 M

            B.         3.0  x  10-19 M

            C.        6.0  x  10-19 M

            D.        7.7  x  10-10 M

 

13. A solution containing an unknown cation was added to three solutions and the following observations were recorded:

Solution                        NaI                              Na2SO4                        NaOH

Observation                  no precipitate                precipitate                    no precipitate   

The unknown cation is

           

A.        Pb2+

            B.        Sr2+

            C.        Ca2+

            D.        Ag+

 

14. If the solubility of Pb(OH)2 is 0.155 g/L, then the concentration of each ion in a saturated solution is

 

            A.        [Pb2+]  =  0.155 g/L and [OH-]  = 0.155 g/L

            B.         [Pb2+]  =  0.155 g/L and [OH-]  = 0.103 g/L

            C.        [Pb2+]  =  6.43 x 10-4 M and [OH-]  = 1.29 x 10-3 M

            D.        [Pb2+]  =  6.43 x 10-4 M and [OH-]  = 6.43 x 10-3 M

 

15. Which of the following could be used to separate Pb2+ from Ba2+ by precipitation?

 

            A.        Na2S

            B.         NaOH

            C.        Na2CO3

            D.        Na2SO4

 

16. When dissolved in water, which of the following form a molecular solution?

 

            A.        HCl(g)

            B.         NaNO3(s)

            C.        CH3OH(l)

            D.        K2SO4(s)

 

17. Which of the following will be most soluble in water at 25 oC.

           

A.        AgI

            B.         PbS

            C.        MgSO4

            D.        Ba(OH)2

18. At 25 oC, the solubility of Mg(OH)2 is

 

            A.        1.  x 10-32 M

            B.         1.  x 10-12 M

            C.        1.  x 10-6 M

            D.        1.  x 10-4 M

 

19. At 25 oC, the solubility of an unknown compound is 7.1 x 10-5 M. The compound is

 

            A.        CuI

            B.         AgI

            C.        CaCO3

            D.        CaSO4

 

20. When solid AgBr is added to a saturated solution of AgBr, the reaction rates can be described as:

                        Rate of Dissolving                     Rate of Crystalizing

           

A.        increasing                               increasing

B.         increasing                                 decreasing

C.        decreasing                                increasing

D.        increasing                                 no change

 

21. The solubility of PbS is 2.9 x 10-14 M. What is the value of the Ksp.

 

            A.        8.4 x 10-28

            B.         2.9 x 10-14

            C.        5.8 x 10-14

            D.        1.7 x 10-7

 

22. Which of the following causes a precipitate to form when Sr2+(aq) is added but not when Zn2+(aq) is added?

 

            A.        S2-

            B.         Cl-

            C.        SO42-

            D.        CO32-

 

23. A 3.0 L solution of NiCl2 is found to have a chloride concentration of 0.60 M. The concentration of nickel II ions is

 

            A.        0.30 M

B.         0.60 M

C.        0.90 M

D.        1.2 M

 

24. When equal volumes of 0.20 M K2CO3 and 0.2 M Na3PO4 are mixed,

 

            A.        no precipitate will form

            B.         a precipitate of K3PO4 will form

            C.        a precipitate of Na2CO3 will form

            D.        a precipitate of K3PO4 and Na2CO3 will form

 

25. A solution of AgNO3 is slowly added to a mixture containing 0.10 M I-, Cl-, Br-, and IO3-. The precipitate which forms first is

 

            A.        AgI

            B.         AgCl

            C.        AgBr

            D.        AgIO3

 

26. Which of the following units can be used to represent solubility?

 

            A.        g

            B.         mol

            C.        mol/L

            D.        mL/s

 

27. Consider the following equilibrium:  CaCO3(s) ⇄  Ca2+(aq)  +  CO32-(aq)

Which of the following reagents when added to the equilibrium system, would cause more CaCO3 to dissolve?

           

A.        KNO3(s)

            B.         CaCO3(s)

            C.        H2C2O4(s)

            D.        Na2CO3(s)

 

28. Which of the following could be used to precipitate both Mg2+ and Ca2+ from hard water?

 

            A.        lithium sulphate

            B.        sodium phosphate

            C.        potassium sulphide

            D.        ammonium chloride

 

29. What is the maximum [Ag+] that can exist in 0.20 M NaBrO3?

 

            A.        1.1 x 10-5 M

            B.         5.3 x 10-5 M

            C.        2.6 x 10-4 M

            D.        7.3 x 10-3 M

 

30. Which of the following ions could be used to separate Cl-(aq) from SO42-(aq) by precipitation?

 

            A.        Ag+

            B.        Ca2+

            C.        NH4+

            D.        Pb2+

 

31. The Ksp expression for a saturated solution Ca3(PO4)2 is

 

            A.        Ksp  =  [Ca2+][PO43-]

            B.        Ksp  =  [Ca2+]3[PO43-]2

            C.        Ksp  =  [3Ca2+][2PO43-]

            D.        Ksp  =  [3Ca2+][2PO43-]

 

32. When Ca(OH)2 attains solubility equilibrium, the

 

            A.        solution will be saturated

            B.         pH will be less than 7

            C.        trial Ksp is less than the Ksp

            D.        concentrations of the ions are equal

 

33. Which of the following describes the changes in ion concentrations when 1.0 g of solid ZnS is added to a saturated solution of ZnS?

 

                        [Zn2+]                                       [S2-]

 

A.        increases                                  decreases

B.         decreases                                 decreases

C.        increases                                  increases

D.        remains constant                    remains constant

 

34. The net ionic equation for the reaction between Sr(OH)2 and H2SO4 is

            A.        H+  +  OH-  →  H2O

            B.         Sr2+  +  SO42-  →  SrSO4

            C.        Sr(OH)2  +  H2SO4  →  SrSO4  +  2H2O

D.        Sr2+  +  2OH-  +  2H+  +  SO42-  →  SrSO4  +  2H2O

 

35. The relationship between the solubility and the size of the Ksp is

 

            A.        there is no relationship

            B.         the smaller the Ksp the greater the solubility

            C.        the greater the Ksp the greater the solubility

            D.        the solubility is always the square root of the Ksp 


36. Which of the following compounds will form a saturated solution with the greatest concentration of Ag+?

 

            A.        AgI

            B.         AgBr

            C.        AgIO3

            D.        AgBrO3

 

37. When equal volumes of 0.20 M CuSO4 and 0.20 M Li2S are combined, the complete ionic equation is

 

            A.        Cu2+(aq)  +  S2-(aq)  →  CuS(s)

            B.         CuSO4(aq)  +  Li2S(aq)  →  CuS(s)  +  Li2SO4(aq)

            C.        Cu2+(aq)  +  SO42-(aq)  +  2Li+(aq)  +  S2-(aq)  →  CuS(s)  +  Li2SO4(aq)

                D.        Cu2+(aq)  +  SO42-(aq)  +  2Li+(aq)  +  S2-(aq)  →  CuS(s)  +  2Li+(aq)  +  SO42-(aq)

 

38. Which of the following would have the [Fe3+] = 0.020 M?

 

            A.        0.40 L of 0.050 M Fe(NO3)3

            B.         0.80 L of 0.020 M Fe2(SO4)3

            C.        0.50 L of 0.040 M FeC6H5O7

            D.        0.50 L of 0.010 M Fe2(C2O4)3

 

39. A solution contains both Ag+ and Mg2+ ions. During selective precipitation, these ions are removed one at a time by adding

 

            A.        I- followed by OH-     

B.         OH- followed by S2-

            C.        SO42- followed by Cl-

            D.        NO3- followed by PO43-

 

40. The solubility of an AB2 type salt is 2.3 x 10-6 M. The salt is

 

            A.        PbBr2

            B.        Fe(OH)2

            C.        Cu(IO3)2

            D.        Mg(OH)2

 

 

 

 

 

 

 

 

 

1. A saturated solution of BaSO4 is given to patients needing digestive tract x-rays.

a) Write an equation that represents the solubility equilibrium

 

BaSO4(s)   ⇄  Ba2+   +   SO42-

 

 

b) Calculate the [Ba2+] present in the saturated solution.

 

 

x2  =  1.1  x  10-10                    [Ba2+]  =  x  =  1.0  x  10-5 M

 

 

 

 

 

2. Will a precipitate form when 90.0 mL of 1.00 x 10-2 M Cu(NO3)2 and 10.0 mL of

1.00 x 10-2 M NaIO3 are mixed? Explain using appropriate calculations.

 

 

Cu(IO3)2(s)       ⇄        Cu2+                 +                      2IO3-

 

                            90 x .0100M                           10 x .0100M

                           100                                          100

 

                           0.00900 M                               0.00100 M

 

Trial ion product = (0.00900)(0.00100)2  =  9.0  x  10-9  <   6.9 x 10-8 (Ksp)  therefore there is no precipitate.

 

 

 

 

 

 

 

3. What is the maximum [CO32-] that can exist in a 1.3 x 10-4 M AgNO3 solution?

 

 

Ag2CO3(s)           ⇄        2Ag+      +       CO32-

                                    1.3 x 10-4 M

                                   

 

Ksp  =  [Ag+]2[CO32-]

 

8.5  x  10-12  =  (1.3 x 10-4)2[CO32-]                 [CO32-]  =  5.0  x  10-4 M

 

 

4. The following data was collected when a 25.00 mL sample of water containing chloride ion was titrated using 0.100M AgNO3 to completely precipitate the chloride ion.

 

Initial volume of AgNO3                        18.30 mL

Final volume of AgNO3                        27.22 mL

 

a) Write the net ionic reaction for the precipitation reaction.

 

 

Ag+        +        Cl-        →        AgCl(s)

 

 

c) Calculate the [Cl-].

 

 

                        0.00892 L Ag+ x  0.100 mole  x  1 mole Cl-

[Cl-]  =                                                  L             1 mole Ag+                  =   3.57  x  10-2 M

                                                            .0250 L

 

 

5. In an experiment to determine the solubility of BaF2, 500.0 mL of the saturated solution was heated in an evaporating dish to remove the water. The evaporating dish and the residue were then heated two more times to ensure all the water was removed.

 

Volume of the saturated solution of BaF2                                               500.0 mL

Mass of the evaporating dish                                                                 72.540 g

Mass of the evaporating dish and BaF2 after the first heating      73.500 g

Mass of the evaporating dish and BaF2 after the second heating 72.855 g

Mass of the evaporating dish and BaF2 after the third heating     72.855 g

 

Using the above data, calculate the Ksp for BaF2

 

Mass of BaF2  =  72.855 – 72.540 = 0.315g

 

 

Molarity         =  0.315g  x     1 mole    

                                                175.3g             =  0.00359 M

                                    .500L

 

 

Ksp  =  [0.00359][.007188]2               =    1.86  x  10-7