Question 1

The substance NaNO3 is considered

Accepted Answer

A)  a weak Arrhenius acid. 
B)  a weak Arrhenius base. 
C)  a strong Arrhenius acid. 
D)  a strong Arrhenius base. 
E)  a neutral compound. 
A)  a weak Arrhenius acid. 
B)  a weak Arrhenius base. 
C)  a strong Arrhenius acid. 
D)  a strong Arrhenius base. 
E)  a neutral compound. E

Question 2

Which of the following is the strongest acid?

Accepted Answer

A)  CH3COOH 
B)  HF 
C)  H3PO4 
D)  H2SO3 
E)  HI 
A)  CH3COOH 
B)  HF 
C)  H3PO4 
D)  H2SO3 
E)  HI E

Question 3

What is the pOH of a 0.0250 M HI solution?

Accepted Answer

A)  0.944 
B)  1.602 
C)  12.398 
D)  13.056 
E)  None of these choices are correct. 
A)  0.944 
B)  1.602 
C)  12.398 
D)  13.056 
E)  None of these choices are correct. C

Question 4

What is the [OH-] for a solution at 25°C that has pH = 4.29?

Accepted Answer

A)  1.4 × 10-2 M 
B)  5.l × 10-5 M 
C)  1.9 × 10-10 M 
D)  7.3 × 10-13 M 
E)  9.71 M 
A)  1.4 × 10-2 M 
B)  5.l × 10-5 M 
C)  1.9 × 10-10 M 
D)  7.3 × 10-13 M 
E)  9.71 M

Question 5

Given: H2O(aq) + H2O(l)   H3O+(aq) + OH-(aq) ΔH°rxn > 0 When the temperature of a sample of pure water is raised above 25°C,

Accepted Answer

A)  the hydronium ion concentration will be greater than the hydroxide ion concentration. 
B)  the hydronium ion concentration will be less than the hydroxide ion concentration. 
C)  the value of Kw will increase. 
D)  the hydronium ion concentration could change to 1.0 × 10-10 M. 
E)  the hydroxide ion concentration could change to 1.0 × 10-10 M. 
A)  the hydronium ion concentration will be greater than the hydroxide ion concentration. 
B)  the hydronium ion concentration will be less than the hydroxide ion concentration. 
C)  the value of Kw will increase. 
D)  the hydronium ion concentration could change to 1.0 × 10-10 M. 
E)  the hydroxide ion concentration could change to 1.0 × 10-10 M.

Question 6

Which, if any, of the following is an example of the leveling effect?

Accepted Answer

A)  The concentrations of H+ and OH- in pure water are equal. 
B)  The number of strong acids equals the number of strong bases. 
C)  The number of strong acids equals the number of weak acids. 
D)  In water, no acid stronger than H3O+ can exist. 
E)  None of these are examples of the leveling effect. 
A)  The concentrations of H+ and OH- in pure water are equal. 
B)  The number of strong acids equals the number of strong bases. 
C)  The number of strong acids equals the number of weak acids. 
D)  In water, no acid stronger than H3O+ can exist. 
E)  None of these are examples of the leveling effect.

Question 7

What is the [H3O+] for a solution at 25°C that has pOH = 5.640?

Accepted Answer

A)  2.34 × 10-4 M 
B)  2.29 × 10-6 M 
C)  4.37 × 10-9 M 
D)  4.27 × 10-11 M 
E)  8.360 M 
A)  2.34 × 10-4 M 
B)  2.29 × 10-6 M 
C)  4.37 × 10-9 M 
D)  4.27 × 10-11 M 
E)  8.360 M

Question 8

Farmers who raise cotton once used arsenic acid, H3AsO4, as a defoliant at harvest time. Arsenic acid is a polyprotic acid with K1 = 2.5 × 10-4, K2 = 5.6 × 10-8, and K3 = 3 × 10-13. What is the pH of a 0.500 M solution of arsenic acid?

Accepted Answer

A)  0.85 
B)  1.96 
C)  3.90 
D)  4.51 
E)  None of these choices are correct. 
A)  0.85 
B)  1.96 
C)  3.90 
D)  4.51 
E)  None of these choices are correct.

Question 9

What is the pH of a 0.0035 M KOH solution?

Accepted Answer

A)  2.46 
B)  5.65 
C)  8.35 
D)  11.54 
E)  None of these choices are correct. 
A)  2.46 
B)  5.65 
C)  8.35 
D)  11.54 
E)  None of these choices are correct.

Question 10

If the compound HX is a strong acid (where H is the acidic proton in this acid), then the ion X- is a weak base.

Accepted Answer

A) True 
 B)False

Question 11

Which of the following is considered a Lewis acid?

Accepted Answer

A)  CH3NH2 
B)  BCl3 
C)  F- 
D)  BF4- 
E)  CH4 
A)  CH3NH2 
B)  BCl3 
C)  F- 
D)  BF4- 
E)  CH4

Question 12

What is the value of Kb for the formate anion, HCOO-? Ka(HCOOH) = 2.1 × 10-4

Accepted Answer

A)  (-2.1 × 10-4) 
B)  2.1 × 10-4 
C)  6.9 × 10-6 
D)  4.8 × 10-11 
E)  2.1 × 10-18 
A)  (-2.1 × 10-4) 
B)  2.1 × 10-4 
C)  6.9 × 10-6 
D)  4.8 × 10-11 
E)  2.1 × 10-18

Question 13

What is the [OH-] for a solution at 25°C that has [H3O+] = 2.35 × 10-3 M?

Accepted Answer

A)  4.26 × 10-5 M 
B)  2.35 × 10-11 M 
C)  4.26 × 10-12 M 
D)  2.35 × 10-17 M 
E)  None of these choices are correct. 
A)  4.26 × 10-5 M 
B)  2.35 × 10-11 M 
C)  4.26 × 10-12 M 
D)  2.35 × 10-17 M 
E)  None of these choices are correct.

Question 14

When 14.7 mL of aqueous HBr (a strong acid) was added to water, 0.482 L of a solution with a pH of 4.23 was produced. What was the molarity of the original HBr solution?

Accepted Answer

A)  1.9 × 10-3 M 
B)  140 M 
C)  0.288 M 
D)  0.13 M 
E)  None of these choices are correct. 
A)  1.9 × 10-3 M 
B)  140 M 
C)  0.288 M 
D)  0.13 M 
E)  None of these choices are correct.

Question 15

Select the pair of substances in that an acid is listed followed by its conjugate base.

Accepted Answer

A)  H+, HCl 
B)  NH3, NH4+ 
C)  HPO42-, H2PO4- 
D)  HCO3-, CO32- 
E)  CH3COOH, CH3COOH2+ 
A)  H+, HCl 
B)  NH3, NH4+ 
C)  HPO42-, H2PO4- 
D)  HCO3-, CO32- 
E)  CH3COOH, CH3COOH2+

Question 16

All weak acids have strong conjugate bases.

Accepted Answer

A) True 
 B)False

Question 17

A solution is prepared by adding 0.10 mol of sodium sulfide, Na2S, to 1.00 L of water. Which statement about the solution is correct?

Accepted Answer

A)  The solution is basic. 
B)  The solution is neutral. 
C)  The solution is acidic. 
D)  The concentration of sodium ions and sulfide ions will be identical. 
E)  The concentration of sulfide ions will be greater than the concentration of sodium ions. 
A)  The solution is basic. 
B)  The solution is neutral. 
C)  The solution is acidic. 
D)  The concentration of sodium ions and sulfide ions will be identical. 
E)  The concentration of sulfide ions will be greater than the concentration of sodium ions.

Question 18

What is the pH of a 0.0125 M NaOH solution?

Accepted Answer

A)  0.972 
B)  1.903 
C)  12.097 
D)  13.028 
E)  None of these choices are correct. 
A)  0.972 
B)  1.903 
C)  12.097 
D)  13.028 
E)  None of these choices are correct.

Question 19

The acid dissociation constant Ka equals 1.26 × 10-2 for HSO4- and is 5.6 × 10-10 for NH4. Which statement about the following equilibrium is correct? HSO4-(aq) + NH3(aq)   SO42-(aq) + NH4+(aq)

Accepted Answer

A)  The reactants will be favored because ammonia is a stronger base than the sulfate anion. 
B)  The products will be favored because the hydrogen sulfate ion is a stronger acid than the ammonium ion. 
C)  Neither reactants nor products will be favored because all of the species are weak acids or bases. 
D)  The initial concentrations of the hydrogen sulfate ion and ammonia must be known before any prediction can be made. 
E)  This reaction is impossible to predict, since the strong acid and the weak base appear on the same side of the equation. 
A)  The reactants will be favored because ammonia is a stronger base than the sulfate anion. 
B)  The products will be favored because the hydrogen sulfate ion is a stronger acid than the ammonium ion. 
C)  Neither reactants nor products will be favored because all of the species are weak acids or bases. 
D)  The initial concentrations of the hydrogen sulfate ion and ammonia must be known before any prediction can be made. 
E)  This reaction is impossible to predict, since the strong acid and the weak base appear on the same side of the equation.

Question 20

In applying molecular orbital theory, the bond order is calculated in the same way as with Lewis structures.

Accepted Answer

A) True 
 B)False

Exam 18: Acid-Base Equilibria

The substance NaNO3 is considered

Which of the following is the strongest acid?

What is the pOH of a 0.0250 M HI solution?

What is the [OH-] for a solution at 25°C that has pH = 4.29?

Given: H2O(aq) + H2O(l) H3O+(aq) + OH-(aq) ΔH°rxn > 0 When the temperature of a sample of pure water is raised above 25°C,

Which, if any, of the following is an example of the leveling effect?

What is the [H3O+] for a solution at 25°C that has pOH = 5.640?

Farmers who raise cotton once used arsenic acid, H3AsO4, as a defoliant at harvest time. Arsenic acid is a polyprotic acid with K1 = 2.5 × 10-4, K2 = 5.6 × 10-8, and K3 = 3 × 10-13. What is the pH of a 0.500 M solution of arsenic acid?

What is the pH of a 0.0035 M KOH solution?

If the compound HX is a strong acid (where H is the acidic proton in this acid), then the ion X- is a weak base.

Which of the following is considered a Lewis acid?

What is the value of Kb for the formate anion, HCOO-? Ka(HCOOH) = 2.1 × 10-4

What is the [OH-] for a solution at 25°C that has [H3O+] = 2.35 × 10-3 M?

When 14.7 mL of aqueous HBr (a strong acid) was added to water, 0.482 L of a solution with a pH of 4.23 was produced. What was the molarity of the original HBr solution?

Select the pair of substances in that an acid is listed followed by its conjugate base.

All weak acids have strong conjugate bases.

A solution is prepared by adding 0.10 mol of sodium sulfide, Na2S, to 1.00 L of water. Which statement about the solution is correct?

What is the pH of a 0.0125 M NaOH solution?

The acid dissociation constant Ka equals 1.26 × 10-2 for HSO4- and is 5.6 × 10-10 for NH4. Which statement about the following equilibrium is correct? HSO4-(aq) + NH3(aq) SO42-(aq) + NH4+(aq)

In applying molecular orbital theory, the bond order is calculated in the same way as with Lewis structures.

Keys to Studying Chemistry Definitions, Units, and Problem Solving

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

Ionic Equilibria in Aqueous Systems

Thermodynamics Entropy, Free Energy, and Reaction Direction

Electrochemistry Chemical Change and Electrical Work

The Elements in Nature and Industry

Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

The substance NaNO₃ is considered

What is the [OH^-] for a solution at 25°C that has pH = 4.29?

Given: H₂O(aq) + H₂O(l) H₃O⁺(aq) + OH^-(aq) ΔH°_rxn > 0 When the temperature of a sample of pure water is raised above 25°C,

What is the [H₃O⁺] for a solution at 25°C that has pOH = 5.640?

Farmers who raise cotton once used arsenic acid, H₃AsO₄, as a defoliant at harvest time. Arsenic acid is a polyprotic acid with K₁ = 2.5 × 10^-4, K₂ = 5.6 × 10^-8, and K₃ = 3 × 10^-13. What is the pH of a 0.500 M solution of arsenic acid?

If the compound HX is a strong acid (where H is the acidic proton in this acid), then the ion X^- is a weak base.

What is the value of K_b for the formate anion, HCOO^-? K_a(HCOOH) = 2.1 × 10^-4

What is the [OH-] for a solution at 25°C that has [H₃O⁺] = 2.35 × 10^-3 M?

A solution is prepared by adding 0.10 mol of sodium sulfide, Na₂S, to 1.00 L of water. Which statement about the solution is correct?

The acid dissociation constant K_a equals 1.26 × 10^-2 for HSO₄^- and is 5.6 × 10^-10 for NH₄. Which statement about the following equilibrium is correct? HSO_4-(aq) + NH₃(aq) SO₄^2-(aq) + NH₄⁺(aq)