Question 1

For which of the following polyprotic acids is the first ionization step approximately 100%?

Accepted Answer

A)  H2S 
B)  H2SO3 
C)  H2CO3 
D)  H2SO4 
E)  H3PO4 
A)  H2S 
B)  H2SO3 
C)  H2CO3 
D)  H2SO4 
E)  H3PO4

Question 2

For the following compound, predict whether the solution is acidic, basic or neutral and why: Na2CO3.

Accepted Answer

A)  acidic because Na2CO3 is a strong acid 
B)  basic because Na2CO3 is a weak base 
C)  neutral because there is no hydrolysis 
D)  basic because Na2CO3 is the salt of a weak acid 
E)  acidic because Na2CO3 is the salt of a weak base 
A)  acidic because Na2CO3 is a strong acid 
B)  basic because Na2CO3 is a weak base 
C)  neutral because there is no hydrolysis 
D)  basic because Na2CO3 is the salt of a weak acid 
E)  acidic because Na2CO3 is the salt of a weak base

Question 3

A 0.0925 g sample of a monoprotic base (mm = 17.03 g/mol) was dissolved in water to produce 100 mL of solution with a pH = 11.00. What is the ionization constant of this base?

Accepted Answer

A)  1.8 × 10-6 
B)  1.8 × 10-11 
C)  1.8 × 10-21 
D)  1.9 × 10-5 
E)  1.1 × 10-6 
A)  1.8 × 10-6 
B)  1.8 × 10-11 
C)  1.8 × 10-21 
D)  1.9 × 10-5 
E)  1.1 × 10-6

Question 4

What is the [AsO43-] for a solution labeled 0.10 M arsenic acid (H3AsO4)? [Ka1 = 6 × 10-3, Ka2 = 1 × 10-7, Ka3 = 3 × 10-12]

Accepted Answer

A)  1 × 10-7 M 
B)  1 × 10-17 M 
C)  3 × 10-12 M 
D)  3 × 10-19 M 
E)  6 × 10-10 M 
A)  1 × 10-7 M 
B)  1 × 10-17 M 
C)  3 × 10-12 M 
D)  3 × 10-19 M 
E)  6 × 10-10 M

Question 5

Choose the INCORRECT statement.

Accepted Answer

A)  H2SO4, HCl, and HNO3 all form H3O+ when reacted with H2O. 
B)  Neutralization takes place when the hydronium ion reacts with the hydroxide ion to form water. 
C)  Br nsted and Lowry suggested that bases be defined as proton acceptors. 
D)  The odor that is noticeable when the stopper is removed from a bottle of aqueous ammonia is good evidence of the strength of the substance as a base. 
E)  Br nsted and Lowry suggested that acids be defined as proton donors. 
A)  H2SO4, HCl, and HNO3 all form H3O+ when reacted with H2O. 
B)  Neutralization takes place when the hydronium ion reacts with the hydroxide ion to form water. 
C)  Br nsted and Lowry suggested that bases be defined as proton acceptors. 
D)  The odor that is noticeable when the stopper is removed from a bottle of aqueous ammonia is good evidence of the strength of the substance as a base. 
E)  Br nsted and Lowry suggested that acids be defined as proton donors.

Question 6

The pH of a solution of NH4C2H3O2 is approximately 7. The best explanation is:

Accepted Answer

A)  This salt does not react with water. 
B)  Ammonium acetate is a weak electrolyte. 
C)  All salts of weak acids and weak bases are neutral. 
D)  Aqueous ammonia and acetic acid have approximately equal ionization constants. 
E)  The salt is a product of a strong acid and a strong base. 
A)  This salt does not react with water. 
B)  Ammonium acetate is a weak electrolyte. 
C)  All salts of weak acids and weak bases are neutral. 
D)  Aqueous ammonia and acetic acid have approximately equal ionization constants. 
E)  The salt is a product of a strong acid and a strong base.

Question 7

A 0.505 g sample of a monoprotic base (mm = 45.09 g/mol) was dissolved in water to produce 100.0 mL of solution with a pH = 11.84. What is the ionization constant of this base?

Accepted Answer

A)  4.3 × 10-5 
B)  1.9 × 10-23 
C)  4.3 × 10-4 
D)  3.4 × 10-1 
E)  1.3 × 10-11 
A)  4.3 × 10-5 
B)  1.9 × 10-23 
C)  4.3 × 10-4 
D)  3.4 × 10-1 
E)  1.3 × 10-11

Question 8

List the following acids in order of increasing strength: 
HClO2   &emsp;HClO3   &emsp;HClO4

Accepted Answer

A)  HClO2 4 3 
B)  HClO4 3 2 
C)  HClO4 2 3 
D)  HClO3 2 4 
A)  HClO2 4 3 
B)  HClO4 3 2 
C)  HClO4 2 3 
D)  HClO3 2 4

Question 9

What is the [H2PO4-] of a solution labeled "0.10 M Phosphoric Acid"? [Ka1 = 7.1 × 10-3; Ka2 = 6.3 × 10-8; Ka3 = 4.2 × 10-13]

Accepted Answer

A)  0.023 M 
B)  6.3 × 10-8 M 
C)  7.1 × 10-3 M 
D)  4.2 × 10-13 M 
E)  0.013 M 
A)  0.023 M 
B)  6.3 × 10-8 M 
C)  7.1 × 10-3 M 
D)  4.2 × 10-13 M 
E)  0.013 M

Question 10

A solution has pOH of -0.47. This means that:

Accepted Answer

A)  the solution has a pH of 13.53 
B)  the solution has an [OH-] = 0.34 M 
C)  the solution has an [OH-] greater than 10.0 M 
D)  the solution has an [OH-] = 2.95 M 
E)  The solution has an [H+] = 2.95 M 
A)  the solution has a pH of 13.53 
B)  the solution has an [OH-] = 0.34 M 
C)  the solution has an [OH-] greater than 10.0 M 
D)  the solution has an [OH-] = 2.95 M 
E)  The solution has an [H+] = 2.95 M

Question 11

What is the concentration of free sulfate ion in a solution labeled "3.6M H2SO4"? [Ka2 = 1.1 × 10-2]

Accepted Answer

A)  0.011 M 
B)  0.040 M 
C)  0.20 M 
D)  0.60 M 
E)  1.8 M 
A)  0.011 M 
B)  0.040 M 
C)  0.20 M 
D)  0.60 M 
E)  1.8 M

Question 12

What is the pH of a 0.375 M solution of benzoic acid? Ka = 6.3 × 10-5

Accepted Answer

A)  8.9 
B)  5.1 
C)  2.3 
D)  0.43 
E)  11.7 
A)  8.9 
B)  5.1 
C)  2.3 
D)  0.43 
E)  11.7

Question 13

A 0.632 M solution of a monoprotic base has a pH of 11.53. What is the ionization constant of this base?

Accepted Answer

A)  1.8 × 10-5 
B)  2.1 × 10-3 
C)  1.6 × 10-23 
D)  5.0 × 10-12 
E)  5.3 × 10-3 
A)  1.8 × 10-5 
B)  2.1 × 10-3 
C)  1.6 × 10-23 
D)  5.0 × 10-12 
E)  5.3 × 10-3

Question 14

Choose the Br∅nsted-Lowry acids and bases in the following equation: NH4+ + OH- ⇌ H2O + NH3

Accepted Answer

A)  acids NH4+, OH- bases H2O, NH3 
B)  acids OH-, H2O bases NH3, NH4+ 
C)  acids NH4+, OH- bases NH4+, H2O 
D)  acids NH4+, H2O bases OH-, NH3 
E)  acids NH4+, NH3 bases OH-, H2O 
A)  acids NH4+, OH- bases H2O, NH3 
B)  acids OH-, H2O bases NH3, NH4+ 
C)  acids NH4+, OH- bases NH4+, H2O 
D)  acids NH4+, H2O bases OH-, NH3 
E)  acids NH4+, NH3 bases OH-, H2O

Question 15

What is the pH of a 0.240 M solution of potassium cyanide? Ka (HCN) = 6.2 × 10-10

Accepted Answer

A)  11.3 
B)  2.7 
C)  4.9 
D)  9.1 
E)  9.4 
A)  11.3 
B)  2.7 
C)  4.9 
D)  9.1 
E)  9.4

Question 16

At 25°C, the pH of pure water is:

Accepted Answer

A) 0 B) >0, 7, <14 E) 14 A) 0 B) >0, 7, <14 E) 14

Question 17

In the following reversible reaction the Br∅nsted acids are ________. HCO3-(aq) + OH-(aq) ⇌ CO32-(aq) + H2O

Accepted Answer

A)  HCO3- and H2O 
B)  HCO3- and CO32- 
C)  OH- and CO32- 
D)  OH- and H2O 
E)  H2O and CO32- 
A)  HCO3- and H2O 
B)  HCO3- and CO32- 
C)  OH- and CO32- 
D)  OH- and H2O 
E)  H2O and CO32-

Question 18

What is the [HPO4-2] of a solution labeled "0.10 M Phosphoric Acid"? [Ka1 = 7.1 × 10-3; Ka2 = 6.3 × 10-8; Ka3 = 4.2 × 10-13]

Accepted Answer

A)  4.2 × 10-13 M 
B)  6.3 × 10-8 M 
C)  7.1 × 10-3 M 
D)  1.6 × 10-9 M 
E)  1.6 × 10-16 M 
A)  4.2 × 10-13 M 
B)  6.3 × 10-8 M 
C)  7.1 × 10-3 M 
D)  1.6 × 10-9 M 
E)  1.6 × 10-16 M

Question 19

Which of the following statements concerning aqueous solutions of salts is FALSE?

Accepted Answer

A)  For any salt of a strong acid and a strong base, the pH will be about 7. 
B)  For any salt of a strong acid and a weak base, the pH will be 7. 
D)  For any salt of a weak acid and a weak base, the pH will be about 7. 
A)  For any salt of a strong acid and a strong base, the pH will be about 7. 
B)  For any salt of a strong acid and a weak base, the pH will be 7. 
D)  For any salt of a weak acid and a weak base, the pH will be about 7.

Question 20

Which of the following are Br∅nsted-Lowry acid? 
I. CH3COOH
II. [Cu(H2O)4]2+
III. H2O
IV. CH3NH2
V. H3O+

Accepted Answer

A)  I), II) and III) 
B)  II), III), and IV) 
C)  I), II), III) and IV) 
D)  I), II), III), and V) 
E)  II), III) and V) 
A)  I), II) and III) 
B)  II), III), and IV) 
C)  I), II), III) and IV) 
D)  I), II), III), and V) 
E)  II), III) and V)

Exam 16: Acids and Bases

For which of the following polyprotic acids is the first ionization step approximately 100%?

For the following compound, predict whether the solution is acidic, basic or neutral and why: Na2CO3.

A 0.0925 g sample of a monoprotic base (mm = 17.03 g/mol) was dissolved in water to produce 100 mL of solution with a pH = 11.00. What is the ionization constant of this base?

What is the [AsO43-] for a solution labeled 0.10 M arsenic acid (H3AsO4)? [Ka1 = 6 × 10-3, Ka2 = 1 × 10-7, Ka3 = 3 × 10-12]

Choose the INCORRECT statement.

The pH of a solution of NH4C2H3O2 is approximately 7. The best explanation is:

A 0.505 g sample of a monoprotic base (mm = 45.09 g/mol) was dissolved in water to produce 100.0 mL of solution with a pH = 11.84. What is the ionization constant of this base?

List the following acids in order of increasing strength: HClO2 HClO3 HClO4

What is the [H2PO4-] of a solution labeled "0.10 M Phosphoric Acid"? [Ka1 = 7.1 × 10-3; Ka2 = 6.3 × 10-8; Ka3 = 4.2 × 10-13]

A solution has pOH of -0.47. This means that:

What is the concentration of free sulfate ion in a solution labeled "3.6M H2SO4"? [Ka2 = 1.1 × 10-2]

What is the pH of a 0.375 M solution of benzoic acid? Ka = 6.3 × 10-5

A 0.632 M solution of a monoprotic base has a pH of 11.53. What is the ionization constant of this base?

Choose the Br∅nsted-Lowry acids and bases in the following equation: NH4+ + OH- ⇌ H2O + NH3

What is the pH of a 0.240 M solution of potassium cyanide? Ka (HCN) = 6.2 × 10-10

At 25°C, the pH of pure water is:

In the following reversible reaction the Br∅nsted acids are ________. HCO3-(aq) + OH-(aq) ⇌ CO32-(aq) + H2O

What is the [HPO4-2] of a solution labeled "0.10 M Phosphoric Acid"? [Ka1 = 7.1 × 10-3; Ka2 = 6.3 × 10-8; Ka3 = 4.2 × 10-13]

Which of the following statements concerning aqueous solutions of salts is FALSE?

Which of the following are Br∅nsted-Lowry acid? I. CH3COOH II. [Cu(H2O)4]2+ III. H2O IV. CH3NH2 V. H3O+

Matter - Its Properties and Measurement

Atoms and the Atomic Theory

Chemical Compounds

Chemical Reactions

Introduction to Reactions in Aqueous Solutions

Gases

Thermochemistry

Electrons in Atoms

The Periodic Table and Some Atomic Properties

Chemical Bonding I: Basic Concepts

Chemical Bonding II: Additional Aspects

Intermolecular Forces: Liquids and Solids

Solutions and Their Physical Properties

Chemical Kinetics

Principles of Chemical Equilibrium

Additional Aspects of Acid-Base Equilibria

Solubility and Complex-Ion Equilibria

Spontaneous Change: Entropy and Free Energy

Electrochemistry

Main Group Elements I: Groups 1, 2, 13, and 14

Main Group Elements II: Groups 18, 17, 16, 15, and Hydrogen

The Transition Elements

Complex Ions and Coordination Compounds

Nuclear Chemistry 1-41

Structures of Organic Compounds

Reactions of Organic Compounds

Chemistry of the Living State

Filters

For the following compound, predict whether the solution is acidic, basic or neutral and why: Na₂CO₃.

What is the [AsO₄^3-] for a solution labeled 0.10 M arsenic acid (H₃AsO₄)? [Ka1 = 6 × 10^-3, Ka₂ = 1 × 10^-7, Ka₃= 3 × 10^-12]

The pH of a solution of NH₄C₂H₃O₂ is approximately 7. The best explanation is:

List the following acids in order of increasing strength: HClO₂ HClO₃ HClO₄

What is the [H₂PO₄^-] of a solution labeled "0.10 M Phosphoric Acid"? [Ka1 = 7.1 × 10^-3; Ka2 = 6.3 × 10^-8; Ka3 = 4.2 × 10^-13]

What is the concentration of free sulfate ion in a solution labeled "3.6M H₂SO₄"? [Ka2 = 1.1 × 10^-2]

What is the pH of a 0.375 M solution of benzoic acid? Ka = 6.3 × 10^-5

Choose the Br∅nsted-Lowry acids and bases in the following equation: NH₄⁺ + OH- ⇌ H₂O + NH₃

What is the pH of a 0.240 M solution of potassium cyanide? Ka (HCN) = 6.2 × 10^-10

In the following reversible reaction the Br∅nsted acids are ________. HCO₃^-(aq) + OH-(aq) ⇌ CO₃^2-(aq) + H₂O

What is the [HPO₄^-2] of a solution labeled "0.10 M Phosphoric Acid"? [Ka1 = 7.1 × 10^-3; Ka₂ = 6.3 × 10^-8; Ka₃ = 4.2 × 10^-13]

Which of the following are Br∅nsted-Lowry acid? I. CH₃COOH II. [Cu(H₂O)₄]²⁺ III. H₂O IV. CH₃NH₂ V. H₃O+