Question 1

Rank H3PO4,H2PO4-,and HPO42- in order of increasing acid strength.

Accepted Answer

A)  HPO42- 2PO4- 3PO4 
B)  H2PO4- 42- 3PO4 
C)  H2PO4- 3PO4 42- 
D)  HPO42- 3PO4 2PO4- 
E)  H3PO4 2PO4- 42- 
A)  HPO42- 2PO4- 3PO4 
B)  H2PO4- 42- 3PO4 
C)  H2PO4- 3PO4 42- 
D)  HPO42- 3PO4 2PO4- 
E)  H3PO4 2PO4- 42-

Question 2

The autoionization of pure water,as represented by the equation below,is known to be endothermic (ΔrΗ > 0).Which of the following correctly states what occurs as the temperature of pure water is raised? H2O(l)+ H2O(l)   H3O+(aq)+ OH-(aq)ΔrΗ > 0

Accepted Answer

A)  Kw decreases,and the hydronium ion concentration decreases. 
B)  Kw decreases,and the hydronium ion concentration increases. 
C)  Kw and the hydronium ion concentration do not change. 
D)  Kw increases,and the hydronium ion concentration decreases. 
E)  Kw increases,and the hydronium ion concentration increases. 
A)  Kw decreases,and the hydronium ion concentration decreases. 
B)  Kw decreases,and the hydronium ion concentration increases. 
C)  Kw and the hydronium ion concentration do not change. 
D)  Kw increases,and the hydronium ion concentration decreases. 
E)  Kw increases,and the hydronium ion concentration increases.

Question 3

Which of the following is the correct hydronium ion ,H3O+,concentration of 0.0013 M KOH(aq)at 25 °C? (Kw = 1.01 × 10-14)

Accepted Answer

A)  7.7 × 10-12 M 
B)  1.3 × 10-3 M 
C)  1.0 × 10-14 M 
D)  1.0 × 10-7 M 
E)  1.3 × 10-17 M 
A)  7.7 × 10-12 M 
B)  1.3 × 10-3 M 
C)  1.0 × 10-14 M 
D)  1.0 × 10-7 M 
E)  1.3 × 10-17 M

Question 4

What is the equilibrium concentration of H2C2O4 in a 0.170 M oxalic acid,H2C2O4,solution? For oxalic acid,Ka1 = 5.6 × 10-2 and Ka2 = 5.1 × 10-5.

Accepted Answer

A)  9.6 × 10-2 M 
B)  9.8 × 10-2 M 
C)  1.7 × 10-1 M 
D)  5.1 × 10-5 M 
E)  7.4 × 10-2 M 
A)  9.6 × 10-2 M 
B)  9.8 × 10-2 M 
C)  1.7 × 10-1 M 
D)  5.1 × 10-5 M 
E)  7.4 × 10-2 M

Question 5

A solution has a hydroxide ion concentration of 0.0040 M.Calculate the pOH of the solution at 25 °C.(Kw = 1.01 × 10-14)

Accepted Answer

A)  11.60 
B)  2.40 
C)  7.00 
D)  8.48 
E)  5.52 
A)  11.60 
B)  2.40 
C)  7.00 
D)  8.48 
E)  5.52

Question 6

What is the hydronium-ion concentration in a solution formed by combining 750 mL of 0.10 M NaOH with 250 mL of 0.30 M HCl? NaOH(aq)+ HCl(aq)→ NaCl(aq)+ H2O(l)

Accepted Answer

A)  0.075 M 
B)  1.7 × 10-13 M 
C)  1.0 × 10-7 M 
D)  0.30 M 
E)  0.10 M 
A)  0.075 M 
B)  1.7 × 10-13 M 
C)  1.0 × 10-7 M 
D)  0.30 M 
E)  0.10 M

Question 7

What is the hydroxide-ion concentration of a 0.190 M sodium oxalate (Na2C2O4)solution? For oxalic acid (H2C2O4),Ka1 = 5.6 × 10-2 and Ka2 = 5.1 × 10-5.(Kw = 1.01 × 10-14)

Accepted Answer

A)  6.1 × 10-6 M 
B)  1.0 × 10-7 M 
C)  7.9 × 10-2 M 
D)  3.1 × 10-3 M 
E)  1.8 × 10-7 M 
A)  6.1 × 10-6 M 
B)  1.0 × 10-7 M 
C)  7.9 × 10-2 M 
D)  3.1 × 10-3 M 
E)  1.8 × 10-7 M

Question 8

The chemical equations below show the reaction of Al(OH)3 as a Lewis acid and as a Lewis base,respectively.
Al(OH)3(s)+ OH-(aq)   Al(OH)4-(aq)
Al(OH)3(s)+ 3 H3O+(aq)   Al3+(aq)+ 3 H2O(   )
Substances that can behave as either Lewis acids or bases are called ________ substances.

Accepted Answer

Question 9

What is the hydronium-ion concentration of a 0.25 M solution of HCN (Ka = 4.9 × 10-10)at 25°C?

Accepted Answer

A)  1.6 × 10-4 M 
B)  3.3 × 10-6 M 
C)  2.1 × 10-6 M 
D)  1.1 × 10-5 M 
E)  4.4 × 10-5 M 
A)  1.6 × 10-4 M 
B)  3.3 × 10-6 M 
C)  2.1 × 10-6 M 
D)  1.1 × 10-5 M 
E)  4.4 × 10-5 M

Question 10

Which are the Brønsted-Lowry bases in the following equilibrium? CH3COO-(aq)+ H2O(l)   CH3COOH(aq)+ OH-(aq)

Accepted Answer

A)  CH3COO- and OH- 
B)  H2O and OH- 
C)  H2O,CH3COOH,and OH- 
D)  CH3COO- and CH3COOH 
E)  H2O and CH3COOH 
A)  CH3COO- and OH- 
B)  H2O and OH- 
C)  H2O,CH3COOH,and OH- 
D)  CH3COO- and CH3COOH 
E)  H2O and CH3COOH

Question 11

Consider the Ka values for the following acids: Cyanic acid,HOCN,3.5 × 10-4
Formic acid,HCHO2,1.7 × 10-4
Lactic acid,HC3H5O3,1.3 × 10-4
Propionic acid,HC3H5O2,1.3 × 10-5
Benzoic acid,HC7H5O2,6.3 × 10-5
Which of the following is the strongest acid?

Accepted Answer

A)  Cyanic acid 
B)  Propionic acid 
C)  Bemzoic acid 
D)  Formic acid 
E)  Lactic acid 
A)  Cyanic acid 
B)  Propionic acid 
C)  Bemzoic acid 
D)  Formic acid 
E)  Lactic acid

Question 12

Which of the following species cannot act as a Lewis base?

Accepted Answer

A)  S2- 
B)  H2S 
C)  NH3 
D)  CH4 
E)  NH- 
A)  S2- 
B)  H2S 
C)  NH3 
D)  CH4 
E)  NH-

Question 13

When a Lewis acid combines with a Lewis base,the base supplies both the electrons to the bond.This type of chemical bond is called a(n)_____ covalent bond.

Accepted Answer

The answer of When a Lewis acid combines with a...

Question 14

Consider the Ka values for the following acids: Cyanic acid,HOCN,3.5 × 10-4
Formic acid,HCHO2,1.7 × 10-4
Lactic acid,HC3H5O3,1.3 × 10-4
Propionic acid,HC3H5O2,1.3 × 10-5
Benzoic acid,HC7H5O2,6.3 × 10-5
Given initially equimolar solutions of each weak acid,which solution will have the highest pH once equilibrium is established?

Accepted Answer

A)  HOCN 
B)  HC7H5O2 
C)  HC3H5O2 
D)  HC3H5O3 
E)  HCHO2 
A)  HOCN 
B)  HC7H5O2 
C)  HC3H5O2 
D)  HC3H5O3 
E)  HCHO2

Question 15

What is the pH of 0.010 M aqueous hypochlorous acid? (Ka of HOCl = 3.5 × 10-8)

Accepted Answer

A)  2.00 
B)  4.50 
C)  4.73 
D)  6.54 
E)  7.45 
A)  2.00 
B)  4.50 
C)  4.73 
D)  6.54 
E)  7.45

Question 16

The pH of aqueous 0.10 M pyridine (C5H5N)ion is 9.09.What is the Kb of this base?

Accepted Answer

A)  8.0 × 10-10 
B)  1.5 × 10-9 
C)  9.0 × 10-6 
D)  1.6 × 10-5 
E)  1.2 × 10-5 
A)  8.0 × 10-10 
B)  1.5 × 10-9 
C)  9.0 × 10-6 
D)  1.6 × 10-5 
E)  1.2 × 10-5

Question 17

H3PO3 is a diprotic weak acid.What is the balanced equilibrium defined as Kb2 of H3PO3?

Accepted Answer

A)  H3PO3(aq)+ H2O(l)   H3O+(aq)+ H2PO3-(aq) 
B)  H2PO3-(aq)+ H2O(l)   H3O+(aq)+ HPO32-(aq) 
C)  HPO32-(aq)+ H2O(l)   OH-(l)+ H2PO3-(aq) 
D)  H2PO3-(aq)+ H2O(l)   OH-(l)+ H3PO3(aq) 
E)  HPO32-(aq)+ H2O(l)   OH-(aq)+ H3PO3(aq) 
A)  H3PO3(aq)+ H2O(l)   H3O+(aq)+ H2PO3-(aq) 
B)  H2PO3-(aq)+ H2O(l)   H3O+(aq)+ HPO32-(aq) 
C)  HPO32-(aq)+ H2O(l)   OH-(l)+ H2PO3-(aq) 
D)  H2PO3-(aq)+ H2O(l)   OH-(l)+ H3PO3(aq) 
E)  HPO32-(aq)+ H2O(l)   OH-(aq)+ H3PO3(aq)

Question 18

Brønsted-Lowry acid-base reactions are restricted to only aqueous solutions.

Accepted Answer

A)  1 only 
B)  2 only 
C)  3 only 
D)  1 and 2 
E)  1,2,and 3 
A)  1 only 
B)  2 only 
C)  3 only 
D)  1 and 2 
E)  1,2,and 3

Question 19

The pH of a solution at 25 °C in which [OH-] = 3.9 × 10-5 M is _____.(Kw = 1.01 × 10-14)

Accepted Answer

A)  4.41 
B)  3.90 
C)  9.59 
D)  4.80 
E)  None of these 
A)  4.41 
B)  3.90 
C)  9.59 
D)  4.80 
E)  None of these

Question 20

Which of the following substances is never a Brønsted-Lowry base in an aqueous solution?

Accepted Answer

A)  potassium hydroxide,NaOH(g) 
B)  sodium hydrogen phosphate,Na2HPO4(s) 
C)  sodium phosphate,Na3PO4(s) 
D)  ammonium chloride,NH4Cl(g) 
E)  sodium bicarbonate,NaHCO3(s) 
A)  potassium hydroxide,NaOH(g) 
B)  sodium hydrogen phosphate,Na2HPO4(s) 
C)  sodium phosphate,Na3PO4(s) 
D)  ammonium chloride,NH4Cl(g) 
E)  sodium bicarbonate,NaHCO3(s)

Exam 17: Principles of Chemical Reactivity: the Chemistry of Acids and Bases

Rank H3PO4,H2PO4-,and HPO42- in order of increasing acid strength.

The autoionization of pure water,as represented by the equation below,is known to be endothermic (ΔrΗ > 0).Which of the following correctly states what occurs as the temperature of pure water is raised? H2O(l)+ H2O(l) H3O+(aq)+ OH-(aq)ΔrΗ > 0

Which of the following is the correct hydronium ion ,H3O+,concentration of 0.0013 M KOH(aq)at 25 °C? (Kw = 1.01 × 10-14)

What is the equilibrium concentration of H2C2O4 in a 0.170 M oxalic acid,H2C2O4,solution? For oxalic acid,Ka1 = 5.6 × 10-2 and Ka2 = 5.1 × 10-5.

A solution has a hydroxide ion concentration of 0.0040 M.Calculate the pOH of the solution at 25 °C.(Kw = 1.01 × 10-14)

What is the hydronium-ion concentration in a solution formed by combining 750 mL of 0.10 M NaOH with 250 mL of 0.30 M HCl? NaOH(aq)+ HCl(aq)→ NaCl(aq)+ H2O(l)

What is the hydroxide-ion concentration of a 0.190 M sodium oxalate (Na2C2O4)solution? For oxalic acid (H2C2O4),Ka1 = 5.6 × 10-2 and Ka2 = 5.1 × 10-5.(Kw = 1.01 × 10-14)

The chemical equations below show the reaction of Al(OH)3 as a Lewis acid and as a Lewis base,respectively. Al(OH)3(s)+ OH-(aq) Al(OH)4-(aq) Al(OH)3(s)+ 3 H3O+(aq) Al3+(aq)+ 3 H2O( ) Substances that can behave as either Lewis acids or bases are called ________ substances.

What is the hydronium-ion concentration of a 0.25 M solution of HCN (Ka = 4.9 × 10-10)at 25°C?

Which are the Brønsted-Lowry bases in the following equilibrium? CH3COO-(aq)+ H2O(l) CH3COOH(aq)+ OH-(aq)

Consider the Ka values for the following acids: Cyanic acid,HOCN,3.5 × 10-4 Formic acid,HCHO2,1.7 × 10-4 Lactic acid,HC3H5O3,1.3 × 10-4 Propionic acid,HC3H5O2,1.3 × 10-5 Benzoic acid,HC7H5O2,6.3 × 10-5 Which of the following is the strongest acid?

Which of the following species cannot act as a Lewis base?

When a Lewis acid combines with a Lewis base,the base supplies both the electrons to the bond.This type of chemical bond is called a(n)_____ covalent bond.

What is the pH of 0.010 M aqueous hypochlorous acid? (Ka of HOCl = 3.5 × 10-8)

The pH of aqueous 0.10 M pyridine (C5H5N)ion is 9.09.What is the Kb of this base?

H3PO3 is a diprotic weak acid.What is the balanced equilibrium defined as Kb2 of H3PO3?

Brønsted-Lowry acid-base reactions are restricted to only aqueous solutions.

The pH of a solution at 25 °C in which [OH-] = 3.9 × 10-5 M is _____.(Kw = 1.01 × 10-14)

Which of the following substances is never a Brønsted-Lowry base in an aqueous solution?

Basic Concepts of Chemistry

Lets Review: The Tools of Quantitative Chemistry

Atoms, molecules, and Ions

Chemical Reactions

Stoichiometry: Quantitative Information About Chemical Reactions

Principles of Chemical Reactivity: Energy and Chemical Reactions

The Structure of Atoms

The Structure of Atoms and Periodic Trends

Bonding and Molecular Structure

Bonding and Molecular Structure Orbital Hybridization and Molecular Orbitals

Gases and Their Properties

Intermolecular Forces and Liquids

The Solid State

Solutions and Their Behavior

Chemical Kinetics: the Rates of Chemical Reactions

Principles of Chemical Reactivity: Equilibria

Principles of Chemical Reactivity: Other Aspects of Aqueous Equilibria

Principles of Chemical Reactivity: Entropy and Free Energy

Principles of Chemical Reactivity: Electron Transfer Reactions

Environmental Chemistry: Earths Environment, energy, and Sustainability

The Chemistry of the Main Group Elements

The Chemistry of the Transition Elements

Carbon: Not Just Another Element

Biochemistry

Nuclear Chemistry

Filters

Rank H₃PO₄,H₂PO₄^-,and HPO₄^2- in order of increasing acid strength.

The autoionization of pure water,as represented by the equation below,is known to be endothermic (Δ_rΗ > 0).Which of the following correctly states what occurs as the temperature of pure water is raised? H₂O(l)+ H₂O(l) H₃O⁺(aq)+ OH^-(aq)Δ_rΗ > 0

Which of the following is the correct hydronium ion ,H₃O⁺,concentration of 0.0013 M KOH(aq)at 25 °C? (K_w = 1.01 × 10^-14)

What is the equilibrium concentration of H₂C₂O₄ in a 0.170 M oxalic acid,H₂C₂O₄,solution? For oxalic acid,K_a1 = 5.6 × 10^-2 and K_a2 = 5.1 × 10^-5.

A solution has a hydroxide ion concentration of 0.0040 M.Calculate the pOH of the solution at 25 °C.(K_w = 1.01 × 10^-14)

What is the hydronium-ion concentration in a solution formed by combining 750 mL of 0.10 M NaOH with 250 mL of 0.30 M HCl? NaOH(aq)+ HCl(aq)→ NaCl(aq)+ H₂O(l)

What is the hydroxide-ion concentration of a 0.190 M sodium oxalate (Na₂C₂O₄)solution? For oxalic acid (H₂C₂O₄),K_a1 = 5.6 × 10^-2 and K_a2 = 5.1 × 10^-5.(K_w = 1.01 × 10^-14)

The chemical equations below show the reaction of Al(OH)₃ as a Lewis acid and as a Lewis base,respectively. Al(OH)₃(s)+ OH^-(aq) Al(OH)₄^-(aq) Al(OH)₃(s)+ 3 H₃O⁺(aq) Al³⁺(aq)+ 3 H₂O( ) Substances that can behave as either Lewis acids or bases are called ________ substances.

What is the hydronium-ion concentration of a 0.25 M solution of HCN (K_a = 4.9 × 10^-10)at 25°C?

Which are the Brønsted-Lowry bases in the following equilibrium? CH₃COO^-(aq)+ H₂O(l) CH₃COOH(aq)+ OH^-(aq)

Consider the K_a values for the following acids: Cyanic acid,HOCN,3.5 × 10^-4Formic acid,HCHO₂,1.7 × 10^-4Lactic acid,HC₃H₅O₃,1.3 × 10^-4Propionic acid,HC₃H₅O₂,1.3 × 10^-5 Benzoic acid,HC₇H₅O₂,6.3 × 10^-5 Which of the following is the strongest acid?

What is the pH of 0.010 M aqueous hypochlorous acid? (K_a of HOCl = 3.5 × 10^-8)

The pH of aqueous 0.10 M pyridine (C₅H₅N)ion is 9.09.What is the K_b of this base?

H₃PO₃ is a diprotic weak acid.What is the balanced equilibrium defined as K_b2 of H₃PO₃?

The pH of a solution at 25 °C in which [OH^-] = 3.9 × 10^-5 M is _____.(K_w = 1.01 × 10^-14)