Question 1

The substance HClO4 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. C

Question 2

What is the pH of a 0.010 M triethanolammonium chloride, (HOC2H2)3NHCl, solution? 
Kb, ((HOC2H2)3N) = 5.9 *10¯7

Accepted Answer

A)  2.75 
B)  4.89 
C)  9.11 
D)  11.25 
E)  None of these choices is correct. 
A)  2.75 
B)  4.89 
C)  9.11 
D)  11.25 
E)  None of these choices is correct. B

Question 3

The English are fond of soggy French fries ("chips") wrapped in old newspaper and generously drenched in vinegar, which is a 0.83 M solution of acetic acid. If the acetic acid in vinegar is 0.47% dissociated, calculate Ka for this acid.

Accepted Answer

K_a = 1.8 *10¯⁵

Question 4

A student adds 0.1 mol of oxalic acid and 0.1 mol of sodium dihydrogen phosphate to enough water to make 1.0 L of solution. The following equilibrium is established with the concentrations of the products greater than the concentrations of the reactants. Which of the statements about the equilibrium system is correct?

Accepted Answer

A)  Oxalic acid is a weaker acid than phosphoric acid. 
B)  The hydrogen oxalate anion, HC2O4¯, is a stronger base than the dihydrogen phosphate anion, H2PO4¯. 
C)  Phosphoric acid is a weaker acid than oxalic acid. 
D)  The dihydrogen phosphate anion, H2PO4¯, is a stronger acid than oxalic acid. 
E)  Water is a stronger acid than either oxalic or phosphoric acids. 
A)  Oxalic acid is a weaker acid than phosphoric acid. 
B)  The hydrogen oxalate anion, HC2O4¯, is a stronger base than the dihydrogen phosphate anion, H2PO4¯. 
C)  Phosphoric acid is a weaker acid than oxalic acid. 
D)  The dihydrogen phosphate anion, H2PO4¯, is a stronger acid than oxalic acid. 
E)  Water is a stronger acid than either oxalic or phosphoric acids.

Question 5

All Brønsted-Lowry bases contain the hydroxide ion, OH¯.

Accepted Answer

A) True 
 B)False

Question 6

A) Write a balanced equation representing the reaction of the acid, H2PO4¯ with the base, water.
B) Write the expression for Ka of H2PO4¯ in terms of concentrations of relevant species.

Accepted Answer

A)11ec9252_d986_1849_b435_a90f

Question 7

Given:   When the temperature of a sample of pure water is raised above 25 $\degree$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 8

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 9

The hydrated Al3+ ion, Al(H2O)63+, is a weak acid in water. What are the products of its reaction with H2O? 
Al(H2O)63+(aq) + H2O(l) $\rightarrow$ ?

Accepted Answer

A)  Al(H2O)5OH2+(aq) + H3O+(aq) 
B)  Al(H2O)6H4+(aq) + OH¯( aq) 
C)  Al(H2O)53+(aq) + 2H2O(l) 
D)  Al(H2O)6OH2+(aq) + H3O+( aq) 
E)  Al(H2O)62+(aq) + H3O+( aq) 
A)  Al(H2O)5OH2+(aq) + H3O+(aq) 
B)  Al(H2O)6H4+(aq) + OH¯( aq) 
C)  Al(H2O)53+(aq) + 2H2O(l) 
D)  Al(H2O)6OH2+(aq) + H3O+( aq) 
E)  Al(H2O)62+(aq) + H3O+( aq)

Question 10

Picric acid has been used in the leather industry and in etching copper. However, its laboratory use has been restricted because it dehydrates on standing and can become shock sensitive. It has an acid dissociation constant of 0.42. What is the [H3O+] for a 0.20 M solution of picric acid?

Accepted Answer

A)  0.022 M 
B)  0.052 M 
C)  0.15 M 
D)  0.29 M 
E)  None of these choices is correct. 
A)  0.022 M 
B)  0.052 M 
C)  0.15 M 
D)  0.29 M 
E)  None of these choices is correct.

Question 11

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 12

What is the [OH¯] for a solution at 25 $\degree$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 is 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 is correct.

Question 13

What is the [OH¯] for a solution at 25 $\degree$C that has [H3O+] = 8.23 *10¯2 M?

Accepted Answer

A)  > 10¯5 M 
B)  1.22 * 10¯6 M 
C)  8.23 *10¯12 M 
D)  1.22 * 10¯13 M 
E)  8.23 * 10¯16 M 
A)  > 10¯5 M 
B)  1.22 * 10¯6 M 
C)  8.23 *10¯12 M 
D)  1.22 * 10¯13 M 
E)  8.23 * 10¯16 M

Question 14

The substance (CH3CH2)2NH 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 15

Which of the following aqueous systems has the highest pH?

Accepted Answer

A)  0.1 M HA, pKa = 11.89 
B)  0.1 M HMO, pKa = 8.23 
C)  0.1 M HA, pKa = 4.55 
D)  0.1 M HBO, pKa = 2.43 
E)  pure water 
A)  0.1 M HA, pKa = 11.89 
B)  0.1 M HMO, pKa = 8.23 
C)  0.1 M HA, pKa = 4.55 
D)  0.1 M HBO, pKa = 2.43 
E)  pure water

Question 16

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 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

Which of the following acids has the lowest pH?

Accepted Answer

A)  0.1 M HBO, pKa = 2.43 
B)  0.1 M HA, pKa = 4.55 
C)  0.1 M HMO, pKa = 8.23 
D)  0.1 M HST, pKa = 11.89 
E)  pure water 
A)  0.1 M HBO, pKa = 2.43 
B)  0.1 M HA, pKa = 4.55 
C)  0.1 M HMO, pKa = 8.23 
D)  0.1 M HST, pKa = 11.89 
E)  pure water

Question 19

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 Ka for the species in solution must be known before a prediction can be made. 
E)  The value of Kb 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 Ka for the species in solution must be known before a prediction can be made. 
E)  The value of Kb for the species in solution must be known before a prediction can be made.

Question 20

Ammonium chloride is used as an electrolyte in dry cells. Which of the following statements about a 0.10 M solution of NH4Cl, is correct?

Accepted Answer

A)  The solution is weakly basic. 
B)  The solution is strongly basic. 
C)  The solution is neutral. 
D)  The solution is acidic. 
E)  The values for Ka and Kb for the species in solution must be known before a prediction can be made. 
A)  The solution is weakly basic. 
B)  The solution is strongly basic. 
C)  The solution is neutral. 
D)  The solution is acidic. 
E)  The values for Ka and Kb for the species in solution must be known before a prediction can be made.

Exam 18: Acid-Base Equilibria

The substance HClO4 is considered

What is the pH of a 0.010 M triethanolammonium chloride, (HOC2H2)3NHCl, solution? Kb, ((HOC2H2)3N) = 5.9 *10¯7

The English are fond of soggy French fries ("chips") wrapped in old newspaper and generously drenched in vinegar, which is a 0.83 M solution of acetic acid. If the acetic acid in vinegar is 0.47% dissociated, calculate Ka for this acid.

All Brønsted-Lowry bases contain the hydroxide ion, OH¯.

A) Write a balanced equation representing the reaction of the acid, H2PO4¯ with the base, water. B) Write the expression for Ka of H2PO4¯ in terms of concentrations of relevant species.

Given: When the temperature of a sample of pure water is raised above 25 °\degree° C,

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

The hydrated Al3+ ion, Al(H2O)63+, is a weak acid in water. What are the products of its reaction with H2O? Al(H2O)63+(aq) + H2O(l) →\rightarrow→ ?

Picric acid has been used in the leather industry and in etching copper. However, its laboratory use has been restricted because it dehydrates on standing and can become shock sensitive. It has an acid dissociation constant of 0.42. What is the [H3O+] for a 0.20 M solution of picric acid?

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 [OH¯] for a solution at 25 °\degree° C that has [H3O+] = 2.35 * 10¯3 M?

What is the [OH¯] for a solution at 25 °\degree° C that has [H3O+] = 8.23 *10¯2 M?

The substance (CH3CH2)2NH is considered

Which of the following aqueous systems has the highest pH?

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 Kb for the formate anion, HCOO¯? Ka(HCOOH) = 2.1 * 10¯4

Which of the following acids has the lowest pH?

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?

Ammonium chloride is used as an electrolyte in dry cells. Which of the following statements about a 0.10 M solution of NH4Cl, is correct?

Keys to the Study of Chemistry

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 the Direction of Chemical Reactions

Electrochemistry: Chemical Change and Electrical Work

The Elements in Nature and Industry

The Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

The substance HClO₄ is considered

What is the pH of a 0.010 M triethanolammonium chloride, (HOC₂H₂)₃NHCl, solution? K_b, ((HOC₂H₂)₃N) = 5.9 *10¯⁷

The English are fond of soggy French fries ("chips") wrapped in old newspaper and generously drenched in vinegar, which is a 0.83 M solution of acetic acid. If the acetic acid in vinegar is 0.47% dissociated, calculate K_a for this acid.

A) Write a balanced equation representing the reaction of the acid, H₂PO₄¯ with the base, water. B) Write the expression for K_a of H₂PO₄¯ in terms of concentrations of relevant species.

Given: $Given: When the temperature of a sample of pure water is raised above 25 \degree C,$ When the temperature of a sample of pure water is raised above 25 $\degree$ C,

The hydrated Al³⁺ ion, Al(H₂O)₆³⁺, is a weak acid in water. What are the products of its reaction with H₂O? Al(H₂O)₆³⁺(aq) + H₂O(l) $\rightarrow$ ?

Picric acid has been used in the leather industry and in etching copper. However, its laboratory use has been restricted because it dehydrates on standing and can become shock sensitive. It has an acid dissociation constant of 0.42. What is the [H₃O⁺] for a 0.20 M solution of picric acid?

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 HONH₂ solution?

What is the [OH¯] for a solution at 25 $\degree$ C that has [H₃O⁺] = 2.35 * 10¯³ M?

What is the [OH¯] for a solution at 25 $\degree$ C that has [H₃O⁺] = 8.23 *10¯² M?

The substance (CH₃CH₂)₂NH is considered

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?

Ammonium chloride is used as an electrolyte in dry cells. Which of the following statements about a 0.10 M solution of NH₄Cl, is correct?