Deck 17: Solubility and Complexation Equilibriums

Question 1

The solubility product of barium sulfate (BaSO₄) is 1.08×10^-10 at $25 ^ { \circ } \mathrm { C }$ . If 15.0mL of 0.0040M Na₂SO₄ is added to 125mL of 6.4×10^-4M BaCl₂, what is the ion product of BaSO₄?

A) 3.89×10^-6 M²
B) 2.45×10^-7 M²
C) 7.20×10^-6 M²
D) 5.98×10^-7 M²
E) 8.86×10^-7 M²

Answer 1

2.45×10^-7 M²

Question 2

If the K_sp for zinc carbonate (ZnCO₃) is 1.46×10^-10 at $25 ^ { \circ } \mathrm { C }$ , what is its aqueous solubility in terms of the mass of salt that dissolves in 100mL of water at the same temperature?

A) 4.98×10^-4
B) 2.87×10^-5
C) 1.52×10^-4
D) 7.35×10^-5
E) 9.14×10^-4

Answer 2

1.52×10^-4

Question 3

The common ion effect usually increases the solubility of a sparingly soluble salt.

Answer 3

False

Question 4

If the ion product of a salt exceeds its solubility product, the solution becomes unsaturated.

Question 5

The concentration of a pure solid appears explicitly in the equilibrium constant expression.

Question 6

If the K_sp of calcium oxalate monohydrate at $42 ^ { \circ } \mathrm { C }$ is 6.45×10^-8, what is its solubility in water at the same temperature?

A) 6.21×10^-4 g/100mL
B) 8.76×10^-3 g/100mL
C) 3.71×10^-3 g/100mL
D) 1.24×10^-4 g/100mL
E) 6.02×10^-3 g/100mL

Question 7

The equilibrium constant expression for the dissolution of calcium phosphate is _____.

A) $\frac { \mathrm { Ca } _ { 3 } \left( \mathrm { PO } _ { 4 } \right) _ { 2 } } { \left[ \mathrm { Ca } ^ { 2 + } \right] ^ { 3 } \left[ \mathrm { PO } _ { 4 } ^ { 3 - } \right] ^ { 2 } }$
B) $\frac { \left[ \mathrm { Ca } ^ { 2 + } \right] ^ { 2 } \left[ \mathrm { PO } _ { 4 } ^ { 3 - } \right] ^ { 3 } } { \mathrm { Ca } _ { 3 } \left( \mathrm { PO } _ { 4 } \right) _ { 2 } }$
C) $\frac { \mathrm { Ca } _ { 3 } \left( \mathrm { PO } _ { 4 } \right) _ { 2 } } { \left[ \mathrm { Ca } ^ { 2 + } \right] ^ { 2 } \left[ \mathrm { PO } _ { 4 } ^ { 3 - } \right] ^ { 3 } }$
D) $\frac { \mathrm { Ca } _ { 3 } \left( \mathrm { PO } _ { 4 } \right) _ { 2 } } { \left[ \mathrm { Ca } ^ { 2 + } \right] ^ { 3 } + \left[ \mathrm { PO } _ { 4 } ^ { 3 - } \right] ^ { 2 } }$
E) $\frac { \left[ \mathrm { Ca } ^ { 2 + } \right] ^ { 3 } \left[ \mathrm { PO } _ { 4 } ^ { 3 - } \right] ^ { 2 } } { \mathrm { Ca } _ { 3 } \left( \mathrm { PO } _ { 4 } \right) _ { 2 } }$

Question 8

Which of the following is true if the ion product is equal to the solubility product?

A) The solution is unsaturated.
B) The ionic solid will dissolve in the solution.
C) The solution is saturated.
D) The solution is supersaturated.
E) The ionic solid will precipitate in the solution.

Question 9

If the K_sp for Ca₃(PO₄)₂ at $30 ^ { \circ } \mathrm { C }$ is 6.47×10^-32, what is the aqueous solubility of Ca₃(PO₄)₂ in terms of the molarity of ions produced in solution?

A) 2.27×10^-7M
B) 6.23×10^-9M
C) 1.44×10^-9M
D) 8.82×10^-7M
E) 5.50×10^-8M

Question 10

Silver sulfate (Ag₂SO4) has a K_sp of 1.20×10^-5 at $25 ^ { \circ } \mathrm { C }$ . If 20.0mL of 0.010M AgNO₃ is added to 120mL of 6.75×10^-3M Na₂SO₄, what is the ion product of silver sulfate?

A) 2.87×10^-7 M²
B) 4.68×10^-6 M²
C) 7.25×10^-6 M²
D) 6.34×10^-7 M²
E) 8.27×10^-6 M²

Question 11

If the K_sp of calcium sulfate (CaSO₄) at $25.0 ^ { \circ } \mathrm { C }$ is 4.93×10^-5, what is its solubility in 0.200M CaCl₂?

A) 6.89×10^-5 M
B) 1.36×10^-5 M
C) 8.78×10^-4 M
D) 2.47×10^-4 M
E) 9.25×10^-5 M

Question 12

The reaction of weakly basic anions with H₂O tends to make the actual solubility of many salts higher than predicted.

Question 13

K_sp is usually expressed in terms of mass of solute per 100mL of solvent.

Question 14

The ion product describes concentrations that are not necessarily equilibrium concentrations.

Question 15

If the K_sp for Ca₃(PO₄)₂ at $30 ^ { \circ } \mathrm { C }$ is 6.47×10^-32, what is the aqueous solubility of Ca₃(PO₄)₂ in terms of the mass of salt that dissolves in 100mL of water at the same temperature?

A) 4.47×10^-5g
B) 2.98×10^-6g
C) 7.65×10^-5g
D) 7.03×10^-6g
E) 5.20×10^-6g

Question 16

The equilibrium constant expression for the dissolution of lead (II) chloride is _____.

A) $\frac { \left[ \mathrm { Pb } ^ { 2 + } \right] ^ { 2 } \left[ \mathrm { Cl } ^ { - } \right] } { \mathrm { PbCl } _ { 2 } }$
B) $\frac { \left[ \mathrm { Pb } ^ { 2 + } \right] \left[ \mathrm { Cl } ^ { - } \right] ^ { 2 } } { \mathrm { PbCl } _ { 2 } }$
C) $\frac { \mathrm { PbCl } _ { 2 } } { \left[ \mathrm {~Pb} ^ { 2 + } \right] \left[ \mathrm { Cl } ^ { - } \right] ^ { 2 } }$
D) $\frac { \left[ \mathrm { Pb } ^ { 2 + } \right] \left[ \mathrm { Cl } ^ { - } \right] } { \mathrm { PbCl } _ { 2 } }$
E) $\frac { \mathrm { PbCl } _ { 2 } } { \left[ \mathrm {~Pb} ^ { 2 + } \right] \left[ \mathrm { Cl } ^ { - } \right] }$

Question 17

Calcium oxalate monohydrate [Ca(O₂CCO₂).H₂O] is a sparingly soluble salt. If its solubility in water at $30 ^ { \circ } \mathrm { C }$ is 8.25×10^-4 g/100mL, what is its K_sp?

A) 3.65×10^-10
B) 7.24×10^-9
C) 5.85×10^-8
D) 3.19×10^-9
E) 9.63×10^-8

Question 18

If the K_sp for calcium phosphate [Ca₃(PO₄)₂] at $25.0 ^ { \circ } \mathrm { C }$ is 2.07×10^-33, what is its solubility in 0.500M CaCl₂?

A) 8.38×10^-16 M
B) 3.62×10^-16 M
C) 1.77×10^-16 M
D) 9.51×10^-17 M
E) 6.43×10^-17 M

Question 19

If the K_sp for zinc carbonate (ZnCO₃) is 1.46×10^-10 at $25 ^ { \circ } \mathrm { C }$ , what is its aqueous solubility in terms of the molarity of ions produced in solution?

A) 1.21×10^-5 M
B) 4.56×10^-5 M
C) 8.13×10^-5 M
D) 3.78×10^-6 M
E) 7.44×10^-6 M

Question 20

Solubility products are determined experimentally by directly measuring the concentration of one of the component ions in a given amount of water.

Question 21

How is the solubility of any sparingly soluble salt influenced by the common ion effect?

Question 22

A molecular solute may be more soluble than predicted by the measured concentrations of ions in solution due to _____.

Question 23

A(n) _____ consists of a cation and an anion that are in intimate contact in solution, rather than separated by solvent.

Question 24

When Hard water is heated, CO₂ gas is released, and the carbonate salts precipitate from solution and produce a solid called _____.

Question 25

The formation of ion pairs decreases the solubility of a salt.

Question 26

Explain the formation of an ion pair.

Question 27

Define the ion product of a salt and state the three possible conditions for an aqueous solution of an ionic solid.
The ion product (Q) of a salt is the product of the concentrations of the ions in solution raised to the same powers as in the solubility product expression. It is analogous to the reaction quotient (Q) discussed for gaseous equilibriums. Whereas K_sp describes equilibrium concentrations, the ion product describes concentrations that are not necessarily equilibrium concentrations. There are three possible conditions for an aqueous solution of an ionic solid:
QK_sp. The solution is unsaturated, and more of the ionic solid, if available, will dissolve.
QThe solution is saturated and at equilibrium.
QThe solution is supersaturated, and ionic solid will precipitate.

Question 28

The solubility product of an ionic compound describes the concentrations of _____ in equilibrium with a solid.

Question 29

The ions in an ion pair migrate as a single unit, whose net charge is the sum of the charges on the ions.

Question 30

The larger the value of the equilibrium constant, the more stable the product.

Question 31

Which of the following acids is most likely to show the highest rate of incomplete dissociation?

A) Sulfuric acid
B) Nitric acid
C) Hypochlorous acid
D) Formic acid
E) Hydrochloric acid

Question 32

A(n) _____ bond holds together undissociated electrolytes, such as C₆H₅CO₂H.

A) polar covalent
B) electrostatic
C) nonpolar covalent
D) ionic
E) metallic

Question 33

Ion pair formation is most important for salts that contain monopositive cations.

Question 34

During the formation of a complex ion, the ligand acts as a Lewis acid.

Question 35

Incomplete dissociation of a molecular solute that is miscible with water can increase the solubility of the solute.

Question 36

The equilibrium constant for the dissolution of a sparingly soluble salt is the _____ of the salt.

Question 37

The formation of an ion pair is a dynamic process.

Question 38

Explain the process of determining the solubility product of a salt.

Question 39

For which of the following salts is ion pair formation considered relatively unimportant?

A) CaCO₃
B) Na₂SO₄
C) MgCl₂
D) CuSO₄
E) AlCl₃

Question 40

The _____ of a salt is the product of the concentrations of the ions in solution raised to the same powers as in the solubility product expression.

Question 41

The equilibrium constant for the formation of a complex ion from a hydrated metal ion is called the _____.

Question 42

If the K_sp of AgCl is equal to 3.89×10^-10 and the K_f of $\mathrm { AgCl } _ { 2 } ^ { - }$ is 2.8×10⁵, what is the equilibrium constant for the reaction?

A) 1.1×10^-4
B) 6.8×10^-5
C) 2.3×10^-5
D) 5.7×10^-4
E) 9.5×10^-4

Question 43

If the K_sp for AgCl is equal to 4.65×10^-9 and the K_f for $\mathrm { AgCl } _ { 2 } ^ { - }$ is equal to 8.7×10⁵ at $35 ^ { \circ } \mathrm { C }$ , what is the solubility of AgCl in pure water at the same temperature?

A) 5.89×10^-6M
B) 7.12×10^-5M
C) 6.82×10^-5M
D) 3.38×10^-6M
E) 8.22×10^-6M

Question 44

Adding a(n) _____ to detergents prevents the magnesium and calcium salts from precipitating because the equilibrium constant for complex-ion formation is large.

Question 45

Fe(II) forms the complex ion [Fe(OH)₄]²⁻ through equilibrium reactions in which hydroxide replaces water in a stepwise manner. If log K₁ = 6.89, log K₂ = 5.42, log K₃ = −0.36, and log K₄ = −1.78, what is its K_f?

A) 8.5×10⁴²
B) 6.8×10⁴⁰
C) 2.1×10⁴¹
D) 1.2×10⁴⁰
E) 4.5×10⁴¹

Question 46

_____ is the universally used compound for developing black-and-white film.

Question 47

If the K_sp for AgCl is equal to 4.65×10^-9 and the K_f for $\mathrm { AgCl } _ { 2 } ^ { - }$ is equal to 8.7×10⁵ at $35 ^ { \circ } \mathrm { C }$ , what is the solubility of AgCl in 1.0 M KCl solution, ignoring the formation of any complex ions?

A) 3.24×10^-10M
B) 6.82×10^-9M
C) 4.67×10^-10M
D) 9.65×10^-9M
E) 4.65×10^-9M

Question 48

A(n) _____ is a species formed between a central metal ion and one or more surrounding ligands, molecules or ions that contain at least one lone pair of electrons.

Question 49

If a complex ion has a large K_f, the formation of a complex ion can dramatically decrease the solubility of sparingly soluble salts.

Question 50

Zn(II) forms the complex ion [Zn(NH₃)₄]²⁺ through equilibrium reactions in which ammonia replaces coordinated water molecules in a stepwise manner. If log K₁ = 3.35, log K₂ = 2.74, log K₃ = 3.50, and log K₄ = 2.25, what is the overall K_f?

A) 3.6×10³⁰
B) 7.2×10²⁹
C) 2.4×10²⁹
D) 9.8×10²⁹
E) 7.4×10³⁰

Question 51

The growth of excessive amounts of algae in a body of water, which can eventually lead to large decreases in levels of dissolved oxygen that kill fish and other aquatic organisms is called _____.

Question 52

If 13.5g of NiCl₂.6H₂O is added to 500mL of 1.50M aqueous ammonia, what is the equilibrium concentration of Ni²⁺(aq)? The complex formed is $\left[ \mathrm { Ni } \left( \mathrm { NH } _ { 3 } \right) _ { 6 } \right] ^ { 2 + }$ Given K_f = 5.5×10⁸.

A) 5.4×10^-10
B) 6.7×10^-9
C) 1.5×10^-10
D) 8.7×10^-8
E) 2.1×10^-9

Question 53

Explain the purpose of adding complexing agents in laundry detergents.

Question 54

Cu(II) forms the complex ion [Cu(H₂O)₆]²⁺ through equilibrium reactions in which ammonia replaces water in a stepwise manner. If log K₁ = 4.78, log K₂ = 2.36, log K₃ = -0.76, and log K₄ = -0.53, what is its K_f?

A) 1.41×10²⁴
B) 4.67×10²³
C) 7.89×10²⁴
D) 4.35×10²⁴
E) 8.54×10²³

Question 55

A(n) _____ is an ion or a molecule that contains one or more pairs of electrons that can be shared with the central metal in a metal complex.

Question 56

If the K_sp of CuCl₂ is 1.72×10^-7 and the equilibrium constant of the reaction is 8.6×10^-2, what is the K_f of $\left[ \mathrm { CuCl } _ { 3 } \right] ^ { 2 - }$ ?

A) 3.6×10⁶
B) 9.5×10⁵
C) 5.0×10⁵
D) 6.3×10⁶
E) 2.2×10⁵

Question 57

Explain the application of complexing agents in the medical industry.

Question 58

Explain the effect of the formation of complex ions on solubility with an example.

Question 59

If 20.0 g of Cu(NO₃)₂.6H₂O is added to 750mL of 1.00M aqueous ammonia, what is the equilibrium concentration of Cu²⁺ (aq) ? The complex formed is $\left[ \mathrm { Cu } \left( \mathrm { NH } _ { 3 } \right) _ { 4 } \right] ^ { 2 + }$ Given K_f = 2.1×10¹³.

A) 4.5×10^-12
B) 2.6×10^-14
C) 1.5×10^-13
D) 6.4×10^-14
E) 8.3×10^-12

Question 60

If the K_f of $\mathrm { AgCl } _ { 2 } ^ { - }$ is 1.1×10⁵ and the equilibrium constant of the reaction is 1.9×10^-5, what is the K_sp of AgCl at $25 ^ { \circ } \mathrm { C }$ ?

A) 4.6×10^-10
B) 8.4×10^-10
C) 6.2×10^-11
D) 1.7×10^-10
E) 2.5×10^-11

Question 61

Which of the following cations is most likely to form acid-insoluble sulfides?

A) Ag⁺
B) Cd²⁺
C) Cr³⁺
D) Mg²⁺
E) NH₄⁺

Question 62

The concentration of anions in solution can often be controlled by adjusting the pH, thereby allowing the selective precipitation of cations.

Question 63

An acidic pH dramatically decreases the solubility of virtually all sparingly soluble salts whose anion is the conjugate base of a weak acid.

Question 64

Ag⁺, Pb²⁺, and Hg₂²⁺ form chlorides that are soluble in water.

Question 65

Metal ions that precipitate together can be separated by changing the pH of the solution.

Question 66

Oxides of elements that are soluble in both acidic and basic solutions are called _____.

Question 67

Which of the following cations is most likely to form base-insoluble sulfides?

A) Zn²⁺
B) Ba³⁺
C) Cu²⁺
D) Li⁺
E) Sn²⁺

Question 68

Oxides of metallic elements are generally acidic oxides.

Question 69

Differentiate between acidic, basic, and amphoteric oxides.

Question 70

Given: K_sp values are 2.32 × 10⁻⁹ for Ca(C₂O₄) and 2.5 × 10⁻²⁷ for La₂(C₂O₄)₃; pK_a1 = 1.25 and pK_a2 = 3.81 for oxalic acid. If a solution contains 0.020M Ca²⁺ and 0.020M La³⁺, what concentration of HCl is needed to precipitate La₂(C₂O₄)₃.9H₂O but not Ca(C₂O₄).H₂O ?
The concentration of oxalic acid is 1.0 M.

A) 6.5 M
B) 9.7 M
C) 4.8 M
D) 2.9 M
E) 8.7 M

Question 71

Consecutive precipitation steps become progressively less selective until almost all of the metal ions are precipitated.

Question 72

Which of the following is the chemical equation that describes the dissolution of aluminum hydroxide in a base?

A) $\mathrm { Al } ( \mathrm { OH } ) _ { 3 } + \mathrm { OH } ^ { - } \rightarrow \left[ \mathrm { Al } ( \mathrm { OH } ) _ { 4 } \right] ^ { - }$
B) $\mathrm { Al } ( \mathrm { OH } ) _ { 3 } + 3 \mathrm { H } ^ { + } \rightarrow \mathrm { Al } ^ { 3 + } + 3 \mathrm { H } _ { 2 } \mathrm { O }$
C) $2 \mathrm { Al } ( \mathrm { OH } ) _ { 3 } + 2 \mathrm { H } ^ { + } \rightarrow 2 \mathrm { Al } _ { 2 } \mathrm { O } _ { 3 } + 2 \mathrm { H } _ { 2 }$
D) $2 \mathrm { Al } ( \mathrm { OH } ) _ { 3 } + 2 \mathrm { OH } ^ { - } \rightarrow \mathrm { Al } _ { 2 } \mathrm { O } _ { 3 } + 4 \mathrm { H } _ { 2 } \mathrm { O }$
E) $\mathrm { Al } ( \mathrm { OH } ) _ { 3 } \rightarrow \mathrm { Al } ^ { 3 + } + 3 \mathrm { OH } ^ { - }$

Question 73

Explain the formation of stalactites and stalagmites in caves.

Question 74

What are amphoteric oxides?

A) They are oxides that dissolve in acid to produce water and dissolve in base to produce a soluble complex.
B) They react with water to produce Lewis bases and react with aqueous ammonia to produce Lewis acids.
C) They are oxides that dissolve only in aqueous bases.
D) They are oxides that react with water to form only basic solutions.
E) They are oxides that react with water to form only acidic solutions.

Question 75

A(n) _____ is a long, hollow spire of limestone that grows down from the ceiling in caves.

Question 76

A(n) _____ is a spire of limestone that grows upwards from the cave floor in the region where the droplets land when they fall from the ceiling.

Question 77

Due to their high electronegativities, nonmetals form oxides with covalent bonds to oxygen.

Question 78

pH has little to no effect on the solubility of salts whose anion is the conjugate base of a stronger weak acid or a strong acid.

Question 79

Which of the following cations is most likely to form insoluble chlorides?

A) Na⁺
B) Ca²⁺
C) Mg²⁺
D) Pb²⁺
E) Fe³⁺

Question 80

Which of the following is the chemical equation that describes the dissolution of aluminum hydroxide in an acid?

A) $\mathrm { Al } ( \mathrm { OH } ) _ { 3 } + \mathrm { OH } ^ { - } \rightarrow \left[ \mathrm { Al } ( \mathrm { OH } ) _ { 4 } \right] ^ { - }$
B) $\mathrm { Al } ( \mathrm { OH } ) _ { 3 } + 3 \mathrm { H } ^ { + } \rightarrow \mathrm { Al } ^ { 3 + } + 3 \mathrm { H } _ { 2 } \mathrm { O }$
C) $2 \mathrm { Al } ( \mathrm { OH } ) _ { 3 } + 2 \mathrm { H } ^ { + } \rightarrow 2 \mathrm { Al } _ { 2 } \mathrm { O } _ { 3 } + 2 \mathrm { H } _ { 2 }$
D) $2 \mathrm { Al } ( \mathrm { OH } ) _ { 3 } + 2 \mathrm { OH } ^ { - } \rightarrow \mathrm { Al } _ { 2 } \mathrm { O } _ { 3 } + 4 \mathrm { H } _ { 2 } \mathrm { O }$
E) $\mathrm { Al } ( \mathrm { OH } ) _ { 3 } \rightarrow \mathrm { Al } ^ { 3 + } + 3 \mathrm { OH } ^ { - }$