Question 1

The pH of a Ba(OH)2 solution is 10.00. What is the H+ ion concentration of this solution?

Accepted Answer

A)  4.0 × 10-11 M 
B)  1.6 × 10-10 M 
C)  1.3 × 10-5 M 
D)  1.0 × 10-10 M 
E)  10.00 M 
A)  4.0 × 10-11 M 
B)  1.6 × 10-10 M 
C)  1.3 × 10-5 M 
D)  1.0 × 10-10 M 
E)  10.00 M

Question 2

After a substance acting as a strong base reacts, what remains of the base?

Accepted Answer

A)  a weaker base 
B)  a strong conjugate acid 
C)  a strong conjugate base 
D)  a strong acid 
E)  a weak conjugate acid 
A)  a weaker base 
B)  a strong conjugate acid 
C)  a strong conjugate base 
D)  a strong acid 
E)  a weak conjugate acid

Question 3

What is [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)  2.35 ×10-3 M 
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)  2.35 ×10-3 M

Question 4

What mass of sodium nitrite must be added to enough water to make 350.0 mL of a solution with pH = 8.40? [Ka(HNO2) = 5.6 × 10-4]

Accepted Answer

A)  68 g 
B)  1.7 × 10-4 g 
C)  0.039 g 
D)  8.7 g 
E)  24 g 
A)  68 g 
B)  1.7 × 10-4 g 
C)  0.039 g 
D)  8.7 g 
E)  24 g

Question 5

Below is a representation of an aqueous solution of a weak acid HA at equilibrium. (Each circle represents 1.0 ×10-3 mol of atoms, and the volume of the box is 1.0 L. Solvent water molecules are not shown for clarity.)   What is Ka of HA?

Accepted Answer

A)  1.0 ×10-6 
B)  6.0 ×10-3 
C)  2.5 ×10-4 
D)  3.6 ×10-5 
E)  1.0 ×10-9 
A)  1.0 ×10-6 
B)  6.0 ×10-3 
C)  2.5 ×10-4 
D)  3.6 ×10-5 
E)  1.0 ×10-9

Question 6

Calculate the pH of a 0.021 M NaCN solution. [Ka(HCN) = 4.9 × 10-10]

Accepted Answer

A)  1.68 
B)  3.19 
C)  4.69 
D)  9.31 
E)  10.81 
A)  1.68 
B)  3.19 
C)  4.69 
D)  9.31 
E)  10.81

Question 7

Find the pH of a 0.135 M aqueous solution of periodic acid (HIO4), for which Ka = 2.3 × 10-2.

Accepted Answer

A)  1.25 
B)  3.28 
C)  1.17 
D)  1.34 
E)  1.64 
A)  1.25 
B)  3.28 
C)  1.17 
D)  1.34 
E)  1.64

Question 8

Which is a Lewis acid but not a Brønsted acid?

Accepted Answer

A)  HCN 
B)  CO32- 
C)  OH- 
D)  Cl- 
E)  Al3+ 
A)  HCN 
B)  CO32- 
C)  OH- 
D)  Cl- 
E)  Al3+

Question 9

Consider the weak bases below and their Kb values: C6H7O- Kb = 1.3 × 10-10
C2H5NH2 Kb = 5.6 × 10-4
C5H5N Kb = 1.7 ×10-9
Arrange the conjugate acids of these weak bases in order of increasing acid strength.

Accepted Answer

A)  C5H5NH+6H7OH 2H5NH 
B)  C6H7OH 5H5NH+ 2H5NH 
C)  C5H5NH+2H5NH3+ 6H7OH 
D)  C6H7OH 2H5NH3+5H5NH+ 
E)  C2H5NH3+5H5NH+ 6H7OH 
A)  C5H5NH+6H7OH 2H5NH 
B)  C6H7OH 5H5NH+ 2H5NH 
C)  C5H5NH+2H5NH3+ 6H7OH 
D)  C6H7OH 2H5NH3+5H5NH+ 
E)  C2H5NH3+5H5NH+ 6H7OH

Question 10

Which one of these salts will form a basic solution upon dissolving in water?

Accepted Answer

A)  NaCl 
B)  NaNO2 
C)  NH4NO3 
D)  KBr 
E)  AlCl3 
A)  NaCl 
B)  NaNO2 
C)  NH4NO3 
D)  KBr 
E)  AlCl3

Question 11

The most acidic oxides are formed from elements found in the ________ region of the periodic table.

Accepted Answer

A)  upper right 
B)  upper left 
C)  center 
D)  lower right 
E)  lower left 
A)  upper right 
B)  upper left 
C)  center 
D)  lower right 
E)  lower left

Question 12

What is the pH of a 0.050 M LiOH solution?

Accepted Answer

A)  1.30 
B)  3.00 
C)  11.00 
D)  12.39 
E)  12.70 
A)  1.30 
B)  3.00 
C)  11.00 
D)  12.39 
E)  12.70

Question 13

The substance (CH3CH2)2NH is considered to be

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 14

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 15

Equal volumes of two solutions, one containing a strong acid at pH 2 and the other containing a strong base at pH 12, are mixed. Once equilibrium is achieved, what is the final pH of the combined solution?

Accepted Answer

A)  6 
B)  7 
C)  10 
D)  14 
E)  24 
A)  6 
B)  7 
C)  10 
D)  14 
E)  24

Question 16

If a strong acid such as HCl is diluted sufficiently with water, the pH will be higher than 7.

Accepted Answer

A) True 
 B)False

Question 17

Which one of the following is a strong acid?

Accepted Answer

A)  H2CO3 
B)  H2SO3 
C)  H2SO4 
D)  H3PO4 
E)  CH3COOH 
A)  H2CO3 
B)  H2SO3 
C)  H2SO4 
D)  H3PO4 
E)  CH3COOH

Question 18

Which is the weakest acid?

Accepted Answer

A)  HBrO3 
B)  HClO 
C)  HBrO2 
D)  HBrO 
E)  HClO3 
A)  HBrO3 
B)  HClO 
C)  HBrO2 
D)  HBrO 
E)  HClO3

Question 19

What is the pH of a 0.20 M solution of NH4Cl? [Kb(NH3) = 1.8 × 10-5]

Accepted Answer

A)  3.74 
B)  4.98 
C)  6.53 
D)  9.02 
E)  11.28 
A)  3.74 
B)  4.98 
C)  6.53 
D)  9.02 
E)  11.28

Question 20

Which is the most basic oxide?

Accepted Answer

A)  Bi2O3 
B)  SiO2 
C)  Cs2O 
D)  Na2O 
E)  H2O 
A)  Bi2O3 
B)  SiO2 
C)  Cs2O 
D)  Na2O 
E)  H2O

Exam 16: Acids and Bases

The pH of a Ba(OH)2 solution is 10.00. What is the H+ ion concentration of this solution?

After a substance acting as a strong base reacts, what remains of the base?

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

What mass of sodium nitrite must be added to enough water to make 350.0 mL of a solution with pH = 8.40? [Ka(HNO2) = 5.6 × 10-4]

Below is a representation of an aqueous solution of a weak acid HA at equilibrium. (Each circle represents 1.0 ×10-3 mol of atoms, and the volume of the box is 1.0 L. Solvent water molecules are not shown for clarity.) What is Ka of HA?

Calculate the pH of a 0.021 M NaCN solution. [Ka(HCN) = 4.9 × 10-10]

Find the pH of a 0.135 M aqueous solution of periodic acid (HIO4), for which Ka = 2.3 × 10-2.

Which is a Lewis acid but not a Brønsted acid?

Consider the weak bases below and their Kb values: C6H7O- Kb = 1.3 × 10-10 C2H5NH2 Kb = 5.6 × 10-4 C5H5N Kb = 1.7 ×10-9 Arrange the conjugate acids of these weak bases in order of increasing acid strength.

Which one of these salts will form a basic solution upon dissolving in water?

The most acidic oxides are formed from elements found in the ________ region of the periodic table.

What is the pH of a 0.050 M LiOH solution?

The substance (CH3CH2)2NH is considered to be

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)

Equal volumes of two solutions, one containing a strong acid at pH 2 and the other containing a strong base at pH 12, are mixed. Once equilibrium is achieved, what is the final pH of the combined solution?

If a strong acid such as HCl is diluted sufficiently with water, the pH will be higher than 7.

Which one of the following is a strong acid?

Which is the weakest acid?

What is the pH of a 0.20 M solution of NH4Cl? [Kb(NH3) = 1.8 × 10-5]

Which is the most basic oxide?

Chemistry: the Central Science

Atoms, Molecules, and Ions

Stoichiometry: Ratios of Combination

Reactions in Aqueous Solutions

Thermochemistry

Quantum Theory and the Electronic Structure of Atoms

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Chemical Bonding II: Molecular Geometry and Bonding Theories

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Intermolecular Forces and the Physical Properties of Liquids and Solids

Modern Materials

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Filters

The pH of a Ba(OH)₂ solution is 10.00. What is the H⁺ ion concentration of this solution?

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

What mass of sodium nitrite must be added to enough water to make 350.0 mL of a solution with pH = 8.40? [K_a(HNO₂) = 5.6 × 10^-4]

Below is a representation of an aqueous solution of a weak acid HA at equilibrium. (Each circle represents 1.0 ×10^-3 mol of atoms, and the volume of the box is 1.0 L. Solvent water molecules are not shown for clarity.) What is K_a of HA?

Calculate the pH of a 0.021 M NaCN solution. [K_a(HCN) = 4.9 × 10^-10]

Find the pH of a 0.135 M aqueous solution of periodic acid (HIO₄), for which K_a = 2.3 × 10^-2.

Consider the weak bases below and their K_b values: C₆H₇O^-^K_b = 1.3 × 10^-10 C₂H₅NH₂K_b = 5.6 × 10^-4 C₅H₅N K_b = 1.7 ×10^-9 Arrange the conjugate acids of these weak bases in order of increasing acid strength.

The substance (CH₃CH₂)₂NH is considered to be

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? HSO₄^-(aq) + NH₃(aq) SO₄^2-(aq) + NH₄⁺(aq)

What is the pH of a 0.20 M solution of NH₄Cl? [K_b(NH₃) = 1.8 × 10^-5]