Question 1

If 10.0 g of NaF and 20.0 g of HF are dissolved in water to make one liter of solution, what will the pH be? For HF, Ka = 6.8 *10¯4

Accepted Answer

A)  7.13 
B)  2.54 
C)  1.57 
D)  3.17 
E)  4.86 
A)  7.13 
B)  2.54 
C)  1.57 
D)  3.17 
E)  4.86

Question 2

When a strong acid is titrated with a weak base, the pH at the equivalence point

Accepted Answer

A)  is greater than 7.0. 
B)  is equal to 7.0. 
C)  is less than 7.0. 
D)  is equal to the pKa of the acid. 
E)  is equal to the pKb of the base. 
A)  is greater than 7.0. 
B)  is equal to 7.0. 
C)  is less than 7.0. 
D)  is equal to the pKa of the acid. 
E)  is equal to the pKb of the base.

Question 3

Calculate the solubility of silver phosphate, Ag3PO4, in pure water. Ksp = 2.6 *10¯18

Accepted Answer

A)  4.0 * 10¯5 M 
B)  1.8 * 10¯5 M 
C)  4.0 *10¯6 M 
D)  1.5 * 10¯6 M 
E)  6 M 
A)  4.0 * 10¯5 M 
B)  1.8 * 10¯5 M 
C)  4.0 *10¯6 M 
D)  1.5 * 10¯6 M 
E)  6 M

Question 4

A buffer is prepared by adding 300.0 mL of 2.0 M NaOH to 500.0 mL of 2.0 M CH3COOH. What is the pH of this buffer? Ka = 1.8 * 10¯5

Accepted Answer

A)  4.57 
B)  4.52 
C)  4.87 
D)  4.92 
E)  4.97 
A)  4.57 
B)  4.52 
C)  4.87 
D)  4.92 
E)  4.97

Question 5

The solubility of silver chloride _______________ when dilute nitric is added to it.

Accepted Answer

A)  increases 
B)  decreases 
C)  does not change 
D)  first increases, then decreases 
E)  first decreases, then increases 
A)  increases 
B)  decreases 
C)  does not change 
D)  first increases, then decreases 
E)  first decreases, then increases

Question 6

Which of the following substances has the greatest solubility in water?

Accepted Answer

A)  MgCO3, Ksp = 3.5*10¯8 
B)  NiCO3, Ksp = 1.3 * 10¯7 
C)  AgIO3, Ksp = 3.1 * 10¯8 
D)  CuBr, Ksp = 5.0 * 10¯9 
E)  AgCN, Ksp = 2.2 *10¯16 
A)  MgCO3, Ksp = 3.5*10¯8 
B)  NiCO3, Ksp = 1.3 * 10¯7 
C)  AgIO3, Ksp = 3.1 * 10¯8 
D)  CuBr, Ksp = 5.0 * 10¯9 
E)  AgCN, Ksp = 2.2 *10¯16

Question 7

Use the following information to calculate the solubility product constant, Ksp, for PbCl2. A saturated solution of PbCl2 in water was prepared and filtered. From the filtrate, 1.0 L was measured out into a beaker and evaporated to dryness. The solid PbCl2 residue recovered in the beaker amounted to 0.0162 moles.

Accepted Answer

A)  Ksp = 6.9 *10¯8 
B)  Ksp = 4.3 * 10¯6 
C)  Ksp = 1.7 * 10¯5 
D)  Ksp = 2.6 *10¯4 
E)  Ksp = 3.2 *10¯2 
A)  Ksp = 6.9 *10¯8 
B)  Ksp = 4.3 * 10¯6 
C)  Ksp = 1.7 * 10¯5 
D)  Ksp = 2.6 *10¯4 
E)  Ksp = 3.2 *10¯2

Question 8

Which of the following has the highest buffer capacity?

Accepted Answer

A)  0.10 M H2PO4¯/0.10 M HPO42¯ 
B)  0.50 M H2PO4¯/0.10 M HPO42¯ 
C)  0.10 M H2PO4¯/0.50 M HPO42¯ 
D)  0.50 M H2PO4¯/0.50 M HPO42¯ 
E)  They all have the same buffer capacity. 
A)  0.10 M H2PO4¯/0.10 M HPO42¯ 
B)  0.50 M H2PO4¯/0.10 M HPO42¯ 
C)  0.10 M H2PO4¯/0.50 M HPO42¯ 
D)  0.50 M H2PO4¯/0.50 M HPO42¯ 
E)  They all have the same buffer capacity.

Question 9

A solution is prepared by adding 4.50 mol of sodium hydroxide to 1.00 L of 1.00 M Co(NO3)2. What is the equilibrium concentration of cobalt ions? Kf = 5.0 *109 for Co(OH)42¯

Accepted Answer

A)  1.1 * 10¯2 M 
B)  1.4 * 10¯5 M 
C)  3.2 *10¯9 M 
D)  2.0* 10¯10 M 
E)  4.9* 10¯13 M 
A)  1.1 * 10¯2 M 
B)  1.4 * 10¯5 M 
C)  3.2 *10¯9 M 
D)  2.0* 10¯10 M 
E)  4.9* 10¯13 M

Question 10

What is the [H3O+] in a solution that consists of 0.15 M C2N2H8 (ethylene diamine) and 0.35 C2N2H9Cl? Kb = 4.7 * 10¯4

Accepted Answer

A)  2.0 * 10¯3 M 
B)  1.1 * 10¯3 M 
C)  6.3 * 10¯9 M 
D)  2.1 * 10¯10 M 
E)  5.0 * 10¯11 M 
A)  2.0 * 10¯3 M 
B)  1.1 * 10¯3 M 
C)  6.3 * 10¯9 M 
D)  2.1 * 10¯10 M 
E)  5.0 * 10¯11 M

Question 11

A popular buffer solution consists of carbonate (CO32¯) and hydrogen carbonate (HCO3¯) conjugate acid-base pair. Which, if any, of the following such buffers has the highest buffer capacity?

Accepted Answer

A)  0.9 M CO32¯ and 0.1 M HCO3¯ 
B)  0.1 M CO32¯ and 0.9 M HCO3¯ 
C)  0.5 M CO32¯ and 0.5 M HCO3¯ 
D)  0.1 M CO32¯ and 0.1 M HCO3¯ 
E)  They all have the same buffer capacity. 
A)  0.9 M CO32¯ and 0.1 M HCO3¯ 
B)  0.1 M CO32¯ and 0.9 M HCO3¯ 
C)  0.5 M CO32¯ and 0.5 M HCO3¯ 
D)  0.1 M CO32¯ and 0.1 M HCO3¯ 
E)  They all have the same buffer capacity.

Question 12

A 35.0-mL sample of 0.20 M LiOH is titrated with 0.25 M HCl. What is the pH of the solution after 23.0 mL of HCl have been added to the base?

Accepted Answer

A)  1.26 
B)  1.67 
C)  12.33 
D)  12.74 
E)  13.03 
A)  1.26 
B)  1.67 
C)  12.33 
D)  12.74 
E)  13.03

Question 13

What mass of NaF must be added to 50.0 mL of a 0.500 M HF solution to achieve a pH of 3.25? For HF, Ka = 7.2 * 10¯4

Accepted Answer

A)  1.3 g 
B)  0.69 g 
C)  6.9 g 
D)  23 g 
E)  1.5 g 
A)  1.3 g 
B)  0.69 g 
C)  6.9 g 
D)  23 g 
E)  1.5 g

Question 14

A 25.0-mL sample of 1.00 M NH3 is titrated with 0.15 M HCl. What is the pH of the solution after 15.00 mL of acid have been added to the ammonia solution? Kb = 1.8 * 10¯5

Accepted Answer

A)  10.26 
B)  9.30 
C)  9.21 
D)  8.30 
E)  8.21 
A)  10.26 
B)  9.30 
C)  9.21 
D)  8.30 
E)  8.21

Question 15

At the equivalence point in an acid-base titration

Accepted Answer

A)  the [H3O+] equals the Ka of the acid. 
B)  the [H3O+] equals the Ka of the indicator. 
C)  the amounts of acid and base which have been combined are in their stoichiometric ratio. 
D)  the pH is 7.0. 
E)  the pH has reached a maximum. 
A)  the [H3O+] equals the Ka of the acid. 
B)  the [H3O+] equals the Ka of the indicator. 
C)  the amounts of acid and base which have been combined are in their stoichiometric ratio. 
D)  the pH is 7.0. 
E)  the pH has reached a maximum.

Question 16

Calculate the solubility of silver chromate, Ag2CrO4, in 0.005 M Na2CrO4. Ksp = 2.6 * 10¯12

Accepted Answer

A)  1.4 * 10¯4 M 
B)  3.4 * 10¯5 M 
C)  1.1 * 10¯5 M 
D)  1.6 * 10¯6 M 
E)  6 M 
A)  1.4 * 10¯4 M 
B)  3.4 * 10¯5 M 
C)  1.1 * 10¯5 M 
D)  1.6 * 10¯6 M 
E)  6 M

Question 17

Increasing the concentrations of the components of a buffer solution will increase the buffer range.

Accepted Answer

A) True 
 B)False

Question 18

If the pH of a buffer solution is greater than the pKa value of the buffer acid, the buffer will have more capacity to neutralize added base than added acid.

Accepted Answer

A) True 
 B)False

Question 19

The salts X(NO3)2 and Y(NO3)2 (where X+ and Y+ are metal ions) are dissolved in water to give a solution which is 0.1 M in each of them. Using the Ksp values listed below, decide which aqueous reagent, if any, will definitely precipitate X+ before precipitating Y+ from solution. Given Ksp values: XCl2, 1 * 10¯5; YCl2, 1 * 10¯10; X(OH)2, 1 * 10¯10; Y(OH)2, 1 * 10¯5

Accepted Answer

A)  1 M NaCl 
B)  1 M HCl 
C)  1 M HNO3 
D)  1 M NaOH 
E)  None of these reagents will accomplish the precipitation. 
A)  1 M NaCl 
B)  1 M HCl 
C)  1 M HNO3 
D)  1 M NaOH 
E)  None of these reagents will accomplish the precipitation.

Question 20

Write the ion product expression for calcium phosphate, Ca3(PO4)2.

Accepted Answer

A)    
B)    
C)    
D)    
E)  None of these choices is correct. 
A)    
B)    
C)    
D)    
E)  None of these choices is correct.

Exam 19: Ionic Equilibria in Aqueous Systems

If 10.0 g of NaF and 20.0 g of HF are dissolved in water to make one liter of solution, what will the pH be? For HF, Ka = 6.8 *10¯4

When a strong acid is titrated with a weak base, the pH at the equivalence point

Calculate the solubility of silver phosphate, Ag3PO4, in pure water. Ksp = 2.6 *10¯18

A buffer is prepared by adding 300.0 mL of 2.0 M NaOH to 500.0 mL of 2.0 M CH3COOH. What is the pH of this buffer? Ka = 1.8 * 10¯5

The solubility of silver chloride _______________ when dilute nitric is added to it.

Which of the following substances has the greatest solubility in water?

Which of the following has the highest buffer capacity?

A solution is prepared by adding 4.50 mol of sodium hydroxide to 1.00 L of 1.00 M Co(NO3)2. What is the equilibrium concentration of cobalt ions? Kf = 5.0 *109 for Co(OH)42¯

What is the [H3O+] in a solution that consists of 0.15 M C2N2H8 (ethylene diamine) and 0.35 C2N2H9Cl? Kb = 4.7 * 10¯4

A popular buffer solution consists of carbonate (CO32¯) and hydrogen carbonate (HCO3¯) conjugate acid-base pair. Which, if any, of the following such buffers has the highest buffer capacity?

A 35.0-mL sample of 0.20 M LiOH is titrated with 0.25 M HCl. What is the pH of the solution after 23.0 mL of HCl have been added to the base?

What mass of NaF must be added to 50.0 mL of a 0.500 M HF solution to achieve a pH of 3.25? For HF, Ka = 7.2 * 10¯4

A 25.0-mL sample of 1.00 M NH3 is titrated with 0.15 M HCl. What is the pH of the solution after 15.00 mL of acid have been added to the ammonia solution? Kb = 1.8 * 10¯5

At the equivalence point in an acid-base titration

Calculate the solubility of silver chromate, Ag2CrO4, in 0.005 M Na2CrO4. Ksp = 2.6 * 10¯12

Increasing the concentrations of the components of a buffer solution will increase the buffer range.

If the pH of a buffer solution is greater than the pKa value of the buffer acid, the buffer will have more capacity to neutralize added base than added acid.

Write the ion product expression for calcium phosphate, Ca3(PO4)2.

Keys to the Study of Chemistry

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Gases and the Kinetic-Molecular Theory

Thermochemistry: Energy Flow and Chemical Change

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

The Shapes of Molecules

Theories of Covalent Bonding

Intermolecular Forces: Liquids, Solids, and Phase Changes

The Properties of Mixtures: Solutions and Colloids

Periodic Patterns in the Main-Group Elements

Organic Compounds and the Atomic Properties of Carbon

Kinetics: Rates and Mechanisms of Chemical Reactions

Equilibrium: the Extent of Chemical Reactions

Acid-Base Equilibria

Thermodynamics: Entropy, Free Energy, and the Direction of Chemical Reactions

Electrochemistry: Chemical Change and Electrical Work

The Elements in Nature and Industry

The Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

If 10.0 g of NaF and 20.0 g of HF are dissolved in water to make one liter of solution, what will the pH be? For HF, K_a = 6.8 *10¯⁴

Calculate the solubility of silver phosphate, Ag₃PO₄, in pure water. K_sp = 2.6 *10¯¹⁸

A buffer is prepared by adding 300.0 mL of 2.0 M NaOH to 500.0 mL of 2.0 M CH₃COOH. What is the pH of this buffer? K_a = 1.8 * 10¯⁵

A solution is prepared by adding 4.50 mol of sodium hydroxide to 1.00 L of 1.00 M Co(NO₃)₂. What is the equilibrium concentration of cobalt ions? K_f = 5.0 *10⁹ for Co(OH)₄²¯

What is the [H₃O⁺] in a solution that consists of 0.15 M C₂N₂H₈ (ethylene diamine) and 0.35 C₂N₂H₉Cl? K_b = 4.7 * 10¯⁴

A popular buffer solution consists of carbonate (CO₃²¯) and hydrogen carbonate (HCO₃¯) conjugate acid-base pair. Which, if any, of the following such buffers has the highest buffer capacity?

What mass of NaF must be added to 50.0 mL of a 0.500 M HF solution to achieve a pH of 3.25? For HF, K_a = 7.2 * 10¯⁴

A 25.0-mL sample of 1.00 M NH₃ is titrated with 0.15 M HCl. What is the pH of the solution after 15.00 mL of acid have been added to the ammonia solution? K_b = 1.8 * 10¯⁵

Calculate the solubility of silver chromate, Ag₂CrO₄, in 0.005 M Na₂CrO₄. K_sp = 2.6 * 10¯¹²

If the pH of a buffer solution is greater than the pK_a value of the buffer acid, the buffer will have more capacity to neutralize added base than added acid.

Write the ion product expression for calcium phosphate, Ca₃(PO₄)₂.