Question 1

Which of the following pairs has the stronger acid listed first?

Accepted Answer

A) HBr, HI 
B) HClO 2, HClO 3 
C) H 2SeO 4, H 2SeO 3 
D) HNO 2, HNO 3 
E) HF, HCl 
A) HBr, HI 
B) HClO 2, HClO 3 
C) H 2SeO 4, H 2SeO 3 
D) HNO 2, HNO 3 
E) HF, HCl

Question 2

The substance NH3 is considered

Accepted Answer

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

Question 3

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 4

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 5

Given: H2O(aq) + H2O(l) ⇄ H3O+(aq) + OH-(aq) ΔH°rxn > 0When 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 K w 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 K w 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

The substance Ca(OH)2 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.

Question 7

A solution of sodium acetate (CH3COONa) in water is weakly basic.

Accepted Answer

A) True 
 B)False

Question 8

Lactic acid has a pKa of 3.08. What is the approximate degree of dissociation of a 0.35 M solution of lactic acid?

Accepted Answer

A) 1.1% 
B) 2.2% 
C) 4.8% 
D) 14% 
E) None of these choices are correct. 
A) 1.1% 
B) 2.2% 
C) 4.8% 
D) 14% 
E) None of these choices are correct.

Question 9

All Brønsted-Lowry bases have at least one lone pair of electrons.

Accepted Answer

A) True 
 B)False

Question 10

What is the value of Kb for the cyanide anion, CN−? Ka(HCN) = 6.2 × 10−10

Accepted Answer

A) 1.6 × 10 −4 
B) 1.6 × 10 −5 
C) 3.8 × 10 −4 
D) 3.8 × 10 −5 
E) 6.2 × 10 4 
A) 1.6 × 10 −4 
B) 1.6 × 10 −5 
C) 3.8 × 10 −4 
D) 3.8 × 10 −5 
E) 6.2 × 10 4

Question 11

The substance Ba(OH)2 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.

Question 12

What is the pH of a 0.050 M HBr solution?

Accepted Answer

A) 0.89 
B) 1.12 
C) 1.30 
D) 3.00 
E) None of these choices are correct. 
A) 0.89 
B) 1.12 
C) 1.30 
D) 3.00 
E) None of these choices are correct.

Question 13

The strongest base which can exist in water is the hydroxide ion.

Accepted Answer

A) True 
 B)False

Question 14

Which one of the following substances will give an aqueous solution of pH < 7?

Accepted Answer

A) KI 
B) NH 4Br 
C) Na 2CO 3 
D) CH 3COONa 
E) CH 3OH 
A) KI 
B) NH 4Br 
C) Na 2CO 3 
D) CH 3COONa 
E) CH 3OH

Question 15

It is not possible to have a pH lying outside the range 0 to 14.

Accepted Answer

A) True 
 B)False

Question 16

Hydroxylamine, HONH2, readily forms salts such as hydroxylamine hydrochloride which are used as antioxidants in soaps. Hydroxylamine has Kb of 9.1 × 10−9. What is the pH of a 0.025 M HONH2 solution?

Accepted Answer

A) 2.90 
B) 4.82 
C) 9.18 
D) 9.91 
E) 11.10 
A) 2.90 
B) 4.82 
C) 9.18 
D) 9.91 
E) 11.10

Question 17

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 18

A solution is prepared by adding 0.10 mol of iron(III) nitrate, Fe(NO3)3, 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 value of K a for the species in solution must be known before a prediction can be made. 
E) The value of K b for the species in solution must be known before a prediction can be made. 
A) The solution is basic. 
B) The solution is neutral. 
C) The solution is acidic. 
D) The value of K a for the species in solution must be known before a prediction can be made. 
E) The value of K b for the species in solution must be known before a prediction can be made.

Question 19

Which one of the following is a Lewis acid but not a Brønsted-Lowry acid?

Accepted Answer

A) Fe 3+ 
B) H 3O + 
C) HSO 4 − 
D) NH 3 
E) H 2O 
A) Fe 3+ 
B) H 3O + 
C) HSO 4 − 
D) NH 3 
E) H 2O

Question 20

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.

Exam 18: Acid-Base Equilibria

Which of the following pairs has the stronger acid listed first?

The substance NH3 is considered

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.

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)

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

The substance Ca(OH)2 is considered

A solution of sodium acetate (CH3COONa) in water is weakly basic.

Lactic acid has a pKa of 3.08. What is the approximate degree of dissociation of a 0.35 M solution of lactic acid?

All Brønsted-Lowry bases have at least one lone pair of electrons.

What is the value of Kb for the cyanide anion, CN−? Ka(HCN) = 6.2 × 10−10

The substance Ba(OH)2 is considered

What is the pH of a 0.050 M HBr solution?

The strongest base which can exist in water is the hydroxide ion.

Which one of the following substances will give an aqueous solution of pH < 7?

It is not possible to have a pH lying outside the range 0 to 14.

Hydroxylamine, HONH2, readily forms salts such as hydroxylamine hydrochloride which are used as antioxidants in soaps. Hydroxylamine has Kb of 9.1 × 10−9. What is the pH of a 0.025 M HONH2 solution?

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

A solution is prepared by adding 0.10 mol of iron(III) nitrate, Fe(NO3)3, to 1.00 L of water. Which statement about the solution is correct?

Which one of the following is a Lewis acid but not a Brønsted-Lowry acid?

The substance NaNO3 is considered

Keys to the Study of 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 NH₃is considered

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.

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

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

The substance Ca(OH)₂is considered

A solution of sodium acetate (CH₃COONa) in water is weakly basic.

Lactic acid has a pK_a of 3.08. What is the approximate degree of dissociation of a 0.35 M solution of lactic acid?

What is the value of K_b for the cyanide anion, CN⁻? K_a(HCN) = 6.2 × 10⁻¹⁰

The substance Ba(OH)₂is considered

Hydroxylamine, HONH₂, readily forms salts such as hydroxylamine hydrochloride which are used as antioxidants in soaps. Hydroxylamine has K_b of 9.1 × 10⁻⁹. What is the pH of a 0.025 M HONH₂solution?

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

A solution is prepared by adding 0.10 mol of iron(III) nitrate, Fe(NO₃)₃, to 1.00 L of water. Which statement about the solution is correct?

The substance NaNO₃is considered