Question 1

Which of the following equilibria represents the second ionization step of H3PO4?

Accepted Answer

A)  H3PO4(aq) + H2O(l) ⇌ H2PO4-(aq) + H3O+(aq) 
B)  H3PO4(aq) + 2H2O(l) ⇌ HPO42-(aq) + 2H3O+(aq) 
C)  H2PO4-(aq) + H2O(l) ⇌ HPO42-(aq) + H3O+(aq) 
D)  HPO42-(aq) + H2O(aq)⇌ PO43-(aq) + H3O+(aq) 
E)  H3PO4(aq) + 3H2O(l) ⇌ PO43-(aq) + 3H3O+(aq) 
A)  H3PO4(aq) + H2O(l) ⇌ H2PO4-(aq) + H3O+(aq) 
B)  H3PO4(aq) + 2H2O(l) ⇌ HPO42-(aq) + 2H3O+(aq) 
C)  H2PO4-(aq) + H2O(l) ⇌ HPO42-(aq) + H3O+(aq) 
D)  HPO42-(aq) + H2O(aq)⇌ PO43-(aq) + H3O+(aq) 
E)  H3PO4(aq) + 3H2O(l) ⇌ PO43-(aq) + 3H3O+(aq)

Question 2

Determine the pOH of a 0.741 mol L-1 KOH solution at 25 °C.

Accepted Answer

A)  0.13 
B)  13.87 
C)  0.17 
D)  12.65 
E)  11.88 
A)  0.13 
B)  13.87 
C)  0.17 
D)  12.65 
E)  11.88

Question 3

Determine the Ka of an acid whose 0.294 mol L-1 solution has a pH of 2.80.

Accepted Answer

A)  1.2 × 10-5 
B)  8.5 × 10-6 
C)  2.7 
D)  4.9 × 10-7 
E)  5.4 × 10-3 
A)  1.2 × 10-5 
B)  8.5 × 10-6 
C)  2.7 
D)  4.9 × 10-7 
E)  5.4 × 10-3

Question 4

Which of the following is a Bronsted-Lowry base?

Accepted Answer

A)  CH4 
B)  HCN 
C)  NH3 
D)  Cl2 
E)  B2H6 
A)  CH4 
B)  HCN 
C)  NH3 
D)  Cl2 
E)  B2H6

Question 5

Which of the following is a Bronsted-Lowry acid?

Accepted Answer

A)  NH4+ 
B)  CH4 
C)  NH2- 
D)  NH3 
E)  Br2 
A)  NH4+ 
B)  CH4 
C)  NH2- 
D)  NH3 
E)  Br2

Question 6

Which of the following is a strong base?

Accepted Answer

A)  Cl- 
B)  NH3 
C)  CH3OH 
D)  NO3⁻ 
E)  KOH 
A)  Cl- 
B)  NH3 
C)  CH3OH 
D)  NO3⁻ 
E)  KOH

Question 7

The pH of an aqueous solution at 25.0 °C is 10.55. What is the molarity of   in this solution?

Accepted Answer

A)  2.8 × 10-11 mol L-1 
B)  3.5 × 1010 mol L-1 
C)  3.5 × 10-4 mol L-1 
D)  3.5 mol L-1 
E)  2.36 mol L-1 
A)  2.8 × 10-11 mol L-1 
B)  3.5 × 1010 mol L-1 
C)  3.5 × 10-4 mol L-1 
D)  3.5 mol L-1 
E)  2.36 mol L-1

Question 8

Calculate the pH of a 0.800 mol L-1 NaCH3CO2 solution. Ka for acetic acid, CH3CO2H, is  1.8 x 10-5

Accepted Answer

A)  2. 42 
B)  4.68 
C)  9.32 
D)  11. 58 
A)  2. 42 
B)  4.68 
C)  9.32 
D)  11. 58

Question 9

Calculate the pOH of a solution that contains 3.9 × 10-4 mol L-1 H3O⁺ at 25 °C.

Accepted Answer

A)  4.59 
B)  3.31 
C)  10.59 
D)  9.14 
E)  0.59 
A)  4.59 
B)  3.31 
C)  10.59 
D)  9.14 
E)  0.59

Question 10

Which of the following is a Lewis acid?

Accepted Answer

A)  BCl3 
B)  CH4 
C)  NH3 
D)  CHCl3 
E)  CCl4 
A)  BCl3 
B)  CH4 
C)  NH3 
D)  CHCl3 
E)  CCl4

Question 11

Determine the pH of a 0.18 mol L-1 H2CO3 solution. Carbonic acid is a diprotic acid whose Ka1 = 4.3 × 10-7 and Ka2 = 5.6 × 10-11.

Accepted Answer

A)  11.00 
B)  10.44 
C)  5.50 
D)  4.31 
E)  3.56 
A)  11.00 
B)  10.44 
C)  5.50 
D)  4.31 
E)  3.56

Question 12

Which of the following bases is the weakest? The base is followed by its Kb value.

Accepted Answer

A)  HOCH2CH2NH2, 3.2 × 10-5 
B)  NH3, 1.76 × 10-5 
C)  C5H5N, 1.7 × 10-9 
D)  (CH3CH2)3N, 5.2 × 10-4 
E)  CH3CH2NH2, 5.6 × 10-4 
A)  HOCH2CH2NH2, 3.2 × 10-5 
B)  NH3, 1.76 × 10-5 
C)  C5H5N, 1.7 × 10-9 
D)  (CH3CH2)3N, 5.2 × 10-4 
E)  CH3CH2NH2, 5.6 × 10-4

Question 13

Determine the pH of a 0.023 mol L-1 HNO3 solution.

Accepted Answer

A)  12.36 
B)  3.68 
C)  1.64 
D)  2.30 
E)  2.49 
A)  12.36 
B)  3.68 
C)  1.64 
D)  2.30 
E)  2.49

Question 14

Which of the following correctly describes the characteristics of a strong acid?

Accepted Answer

A)  ionizes only partially in aqueous solutions 
B)  has a very electron positive atom attached to the oxygen 
C)  has a nonpolar bond 
D)  is completely ionized in aqueous solution 
E)  is always monoprotic 
A)  ionizes only partially in aqueous solutions 
B)  has a very electron positive atom attached to the oxygen 
C)  has a nonpolar bond 
D)  is completely ionized in aqueous solution 
E)  is always monoprotic

Question 15

Which of the following is the correct Arrhenius definition of bases?

Accepted Answer

A)  A base is a substance that produces H+ ions in aqueous solutions. 
B)  A base is a substance that reacts with OH- ions in aqueous solutions. 
C)  A base is a substance that decreases the amount of OH- ions in aqueous solutions. 
D)  A base is a substance that produces OH- ions in aqueous solutions. 
E)  A base is a substance that does not change the concentration of OH- ions in aqueous solutions. 
A)  A base is a substance that produces H+ ions in aqueous solutions. 
B)  A base is a substance that reacts with OH- ions in aqueous solutions. 
C)  A base is a substance that decreases the amount of OH- ions in aqueous solutions. 
D)  A base is a substance that produces OH- ions in aqueous solutions. 
E)  A base is a substance that does not change the concentration of OH- ions in aqueous solutions.

Question 16

Identify the weak diprotic acid.

Accepted Answer

A)  HNO3 
B)  H3PO4 
C)  H2SO3 
D)  HClO4 
E)  H2SO4 
A)  HNO3 
B)  H3PO4 
C)  H2SO3 
D)  HClO4 
E)  H2SO4

Question 17

What is the selenide ion concentration [Se2-] for a 0. 100 mol L-1 H2Se solution that has the stepwise dissociation constants of   and

Accepted Answer

A)  3.6 × 10-3 mol L-1 
B)  1.3 × 10-4 mol L-1 
C)  1.3 × 10-5 mol L-1 
D)  1.0 × 10-11 mol L-1 
A)  3.6 × 10-3 mol L-1 
B)  1.3 × 10-4 mol L-1 
C)  1.3 × 10-5 mol L-1 
D)  1.0 × 10-11 mol L-1

Question 18

What does the term amphoteric mean?

Accepted Answer

A substance is ampho

Question 19

Find the correct equilibrium constant that shows the ionization constant of a weak acid HA.

Accepted Answer

A)  Ka =   
B)  Ka =   
C)  Ka =   
D)  Ka =   
E)  Ka =   
A)  Ka =   
B)  Ka =   
C)  Ka =   
D)  Ka =   
E)  Ka =

Question 20

Determine the pH of a 0.051 mol L-1 Sr(OH)2 solution at 25 °C.

Accepted Answer

A)  8.62 
B)  13.01 
C)  13.37 
D)  0.991 
E)  12.56 
A)  8.62 
B)  13.01 
C)  13.37 
D)  0.991 
E)  12.56

Exam 15: Acids and Bases

Which of the following equilibria represents the second ionization step of H3PO4?

Determine the pOH of a 0.741 mol L-1 KOH solution at 25 °C.

Determine the Ka of an acid whose 0.294 mol L-1 solution has a pH of 2.80.

Which of the following is a Bronsted-Lowry base?

Which of the following is a Bronsted-Lowry acid?

Which of the following is a strong base?

The pH of an aqueous solution at 25.0 °C is 10.55. What is the molarity of in this solution?

Calculate the pH of a 0.800 mol L-1 NaCH3CO2 solution. Ka for acetic acid, CH3CO2H, is 1.8 x 10-5

Calculate the pOH of a solution that contains 3.9 × 10-4 mol L-1 H3O⁺ at 25 °C.

Which of the following is a Lewis acid?

Determine the pH of a 0.18 mol L-1 H2CO3 solution. Carbonic acid is a diprotic acid whose Ka1 = 4.3 × 10-7 and Ka2 = 5.6 × 10-11.

Which of the following bases is the weakest? The base is followed by its Kb value.

Determine the pH of a 0.023 mol L-1 HNO3 solution.

Which of the following correctly describes the characteristics of a strong acid?

Which of the following is the correct Arrhenius definition of bases?

Identify the weak diprotic acid.

What is the selenide ion concentration [Se2-] for a 0. 100 mol L-1 H2Se solution that has the stepwise dissociation constants of and

What does the term amphoteric mean?

Find the correct equilibrium constant that shows the ionization constant of a weak acid HA.

Determine the pH of a 0.051 mol L-1 Sr(OH)2 solution at 25 °C.

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Filters

Which of the following equilibria represents the second ionization step of H₃PO₄?

Determine the pOH of a 0.741 mol L^-1 KOH solution at 25 °C.

Determine the K_a of an acid whose 0.294 mol L^-1 solution has a pH of 2.80.

Calculate the pH of a 0.800 mol L^-1 NaCH₃CO₂ solution. K_a for acetic acid, CH₃CO₂H, is 1.8 x 10^-5

Calculate the pOH of a solution that contains 3.9 × 10^-4 mol L^-1 H₃O⁺ at 25 °C.

Determine the pH of a 0.18 mol L^-1 H₂CO₃ solution. Carbonic acid is a diprotic acid whose K_a₁ = 4.3 × 10^-7 and K_a2 = 5.6 × 10^-11.

Which of the following bases is the weakest? The base is followed by its K_b value.

Determine the pH of a 0.023 mol L^-1 HNO₃ solution.

What is the selenide ion concentration [Se^2-] for a 0. 100 mol L^-1 H₂Se solution that has the stepwise dissociation constants of and

Determine the pH of a 0.051 mol L^-1 Sr(OH)₂ solution at 25 °C.