Deck 13: Acids and Bases

Question 1

The substance NaOH(aq)is

A)a strong acid.
B)a weak acid.
C)a strong base.
D)a weak base.
E)neither an acid nor a base.

Answer 1

a strong base.

Question 2

Which of the following statements regarding acids is incorrect?

A)An acid will react with an active metal.
B)An acid is a substance that will change the color of blue litmus paper.
C)An acid is a substance that would taste sour.
D)An acid is a substance that produces hydrogen ions, H⁺, (or H₃O⁺)in aqueous solution.
E)An acid is always a strong electrolyte.

Answer 2

An acid is always a strong electrolyte.

Question 3

Which of the following statements regarding bases is incorrect?

A)A base is a substance that may act as an antacid.
B)A base is a substance that will not change the color of red litmus paper.
C)A base is a substance that tastes bitter.
D)A base is a substance that produces hydroxide ions, OH⁻, in aqueous solution.
E)A base is a substance that is an electrolyte.

Answer 3

A base is a substance that will not change the color of red litmus paper.

Question 4

Select the two Brønsted-Lowry acids in the following equation: HF(aq)+ H₂O(l)⇌ F⁻(aq)+ H₃O⁺(aq)

A)HF and H₂O
B)HF and F⁻
C)H₂O and F⁻
D)HF and H₃O⁺
E)H₃O⁺ and F⁻

Question 5

The substance HNO₃(aq)is

A)a strong acid.
B)a weak acid.
C)a strong base.
D)a weak base.
E)neither an acid nor a base.

Question 6

List the acid, base, conjugate acid, and conjugate base, in that order, for the following reaction: HOCl(aq)+ H₂O(l)⇌ OCl⁻(aq)+ H₃O⁺(aq)

A)HOCl, H₂O, OCl⁻, H₃O⁺
B)H₂O, HOCl, OCl⁻, H₃O⁺
C)HOCl, H₂O, H₃O⁺, OCl⁻
D)H₂O, HOCl, H₃O⁺, OCl⁻
E)OCl⁻, H₃O⁺, H₂O, HOCl

Question 7

Select the two Brønsted-Lowry acids in the following equation: HNO₂(aq)+ H₂O(l)⇌ NO₂⁻(aq)+ H₃O⁺(aq)

A)HNO₂ and H₂O
B)HNO₂ and NO₂⁻
C)HNO₂ and H₃O⁺
D)H₂O and H₃O⁺
E)NO₂⁻ and H₃O⁺

Question 8

Which of the following bases is not commonly found in household products or antacids?

A)sodium hydroxide, NaOH
B)ammonia, NH₃
C)calcium carbonate, CaCO₃
D)magnesium hydroxide, Mg(OH)₂
E)methyl amine, CH₃NH₂

Question 9

List the acid, base, conjugate acid, and conjugate base, in that order, for the following reaction: CH₃CO₂H(aq)+ H₂O(l)⇌ CH₃CO₂⁻(aq)+ H₃O⁺(aq)

A)CH₃CO₂H, H₂O, CH₃CO₂⁻, H₃O⁺
B)H₂O, CH₃CO₂H, CH₃CO₂⁻, H₃O⁺
C)CH₃CO₂H, H₂O, H₃O⁺, CH₃CO₂⁻
D)H₂O, CH₃CO₂H, H₃O⁺, CH₃CO₂⁻
E)CH₃CO₂⁻, H₃O⁺, H₂O, CH₃CO₂H

Question 10

The substance NH₃(aq)is

A)a strong acid.
B)a weak acid.
C)a strong base.
D)a weak base.
E)neither an acid nor a base.

Question 11

When the following reaction goes in the reverse direction (from products to reactants), what is the acid? HF(aq)+ H₂O(l)⇌ F⁻ (aq)+ H₃O⁺(aq)

A)HF
B)H₂O
C)F⁻
D)H₃O
E)both F⁻ and H₃O

Question 12

Which of the following is not an attribute of an acid?

A)It provides H⁺ ions in aqueous solution.
B)It is a nonelectrolyte.
C)It tastes sour.
D)It reacts with some organic dyes to cause them to change color.
E)It reacts with active metals.

Question 13

Which of the following acids is not normally found in foods or beverages?

A)citric acid
B)acetic acid
C)phosphoric acid
D)carbonic acid
E)sulfuric acid

Question 14

Which of the following is not an attribute of a base?

A)It provides OH⁻ ions in aqueous solution.
B)It is an electrolyte.
C)It reacts with some organic dyes to cause them to change color.
D)It has the ability to neutralize acids.
E)It would taste sour.

Question 15

When the following reaction goes in the reverse direction (from products to reactants), what is the base? HCN(aq)+ H₂O(l)⇌ CN⁻ (aq)+ H₃O⁺(aq)

A)HCN
B)H₂O
C)CN⁻
D)H₃O⁺
E)both CN⁻ and H₃O⁺

Question 16

When the following reaction goes in the reverse direction (from products to reactants), what is the acid? HCN(aq)+ H₂O(l)⇌ CN⁻ (aq)+ H₃O⁺(aq)

A)HCN
B)H₂O
C)CN⁻
D)H₃O⁺
E)both CN⁻ and H₃O⁺

Question 17

When the following reaction goes in the reverse direction (from products to reactants), what is the base? HF(aq)+ H₂O(l)⇌ F⁻(aq)+ H₃O⁺(aq)

A)HF
B)H₂O
C)F⁻
D)H₃O⁺
E)both F⁻ and H₃O⁺

Question 18

The substance Mg(OH)₂(aq)is

A)a strong acid.
B)a weak acid.
C)a strong base.
D)a weak base.
E)neither an acid nor a base.

Question 19

The substance HCl(aq)is

A)a strong acid.
B)a weak acid.
C)a strong base.
D)a weak base.
E)neither an acid nor a base.

Question 20

Select the two Brønsted-Lowry acids in the following equation: HCN(aq)+ H₂O(l)⇌ CN⁻(aq)+ H₃O⁺(aq)

A)HCN and H₂O
B)HCN and CN⁻
C)H₂O and CN⁻
D)HCN and H₃O⁺
E)H₃O⁺ and CN⁻

Question 21

The conjugate base of HCO₃^- is:

A)H₂CO₃
B)HCO₂⁻
C)CO₃²⁻
D)CO₂
E)H₃CO₃⁺

Question 22

When acetate ion, CH₃CO₂⁻, reacts with water, what are the products?

A)H⁺(aq)and OH⁻(aq)
B)CH₃CO₂⁺(aq)and OH⁻(aq)
C)CH₃CO₂⁺(aq)and H₂O(aq)
D)CH₃CO₂⁺(aq)and H⁻(aq)
E)CH₃CO₂H(aq)and OH⁻(aq)

Question 23

Select the two Brønsted-Lowry bases in the following equation: CH₃NH₂(aq)+ H₂O(l)⇌ CH₃NH₃⁺(aq)+ OH⁻(aq)

A)CH₃NH₂ and H₂O
B)CH₃NH₂ and OH⁻
C)H₂O and OH⁻
D)CH₃NH₂ and CH₃NH₃⁺
E)CH₃NH₃⁺ and OH⁻

Question 24

When ammonia, NH₃, is dissolved in water, which ions are formed?

A)NH₃⁻(aq)and OH⁻(aq)
B)NH₃⁺(aq)and OH⁻(aq)
C)NH₄⁺(aq)and OH⁻(aq)
D)NH₄⁺(aq)and H⁻(aq)
E)NH₂⁻(aq)and H⁺(aq)

Question 25

Select the pair that consists of a base and its conjugate acid in that order.

A)NH₃/NH₄⁺
B)HCO₃⁻/CO₃²⁻
C)H₂CO₃/HCO₃⁻
D)H₃PO₄/ HPO₄²⁻
E)CO₃²⁻/CO₂²⁻

Question 26

The conjugate acid of HCO₃⁻ is:

A)H₂CO₃
B)HCO₂⁻
C)CO₃²⁻
D)CO₂
E)H₃CO₃⁺

Question 27

Select the two Brønsted-Lowry bases in the following equation: CO₃²⁻(aq)+ H₂O(l)⇌ HCO₃⁻(aq)+ OH⁻(aq)

A)CO₃²⁻ and H₂O
B)CO₃²⁻ and HCO₃⁻
C)H₂O and OH⁻
D)CO₃²⁻ and OH⁻
E)H₂O and HCO₃⁻

Question 28

The conjugate base of H₂PO₄⁻ is:

A)HPO₄²⁻
B)H₂PO₃⁻
C)H₃PO₄
D)PO₄³⁻
E)H₂PO₄OH⁻

Question 29

The conjugate acid of H₂PO₄⁻ is:

A)HPO₄²⁻
B)H₂PO₃⁻
C)H₃PO₄
D)PO₄³⁻
E)H₃PO₃

Question 30

Select the two Brønsted-Lowry bases in the following equation: NH₃(aq)+ H₂O(aq)⇌ NH₄⁺(aq)+ OH⁻(aq)

A)NH₃ and H₂O
B)NH₃ and OH⁻
C)H₂O and OH⁻
D)NH₃ and NH₄⁺
E)NH₄⁺ and OH⁻

Question 31

Select the pair that consists of a base and its conjugate acid in that order.

A)NH₄⁺/NH₃
B)HCO₃⁻/CO₃²⁻
C)HCO₃⁻/H₂CO₃
D)H₃PO₄/ HPO₄²⁻
E)CO₃²⁻/CO₂²⁻

Question 32

Select the pair that consists of an acid and its conjugate base in that order.

A)NH₃/NH₄⁺
B)CO₃²⁻/HCO₃⁻
C)H₂CO₃/HCO₃⁻
D)HPO₄²⁻/H₃PO₄
E)CO₃^2-/ CO₂^2-

Question 33

Select the pair that consists of an acid and its conjugate base in that order.

A)NH₄⁺/NH₂^-
B)CO₃²⁻/HCO₃⁻
C)CO₃²⁻/H₂CO₃⁻
D)H₂PO₄-/H₃PO₄
E)H₂CO₃/HCO₃⁻

Question 34

Which of the following is an amphoteric substance?

A)NaCl
B)LiOH
C)KBr
D)NaHCO₃
E)CH₃OH

Question 35

Select the two Brønsted-Lowry acids in the following equation: CO₃^2-(aq)+ HF(aq)⇌ HCO₃^-(aq)+ F^-(aq)

A)CO₃^2- and HF
B)CO₃^2- and HCO₃^-
C)HF and F^-
D)CO₃^2- and F^-
E)HF and HCO₃^-

Question 36

Select the pair that consists of an acid and its conjugate base in that order.

A)NH₃/NH₄⁺
B)SO₄²⁻/HSO₃⁻
C)H₂SO₃/HSO₃⁻
D)H₂PO₄⁻/H₃PO₄
E)CO₃²⁻/HCO₃²⁻

Question 37

Select the two Brønsted-Lowry acids in the following equation: NH₃(aq)+ HF(aq)⇌ NH₄⁺(aq)+ F⁻(aq)

A)NH₃ and HF
B)NH₃ and F⁻
C)HF and F⁻
D)NH₄⁺ and F^-
E)HF and NH₄⁺

Question 38

When carbonate ion, CO₃²⁻, reacts with water, what are the products?

A)H⁺(aq)and OH⁻(aq)
B)HCO₃(aq)and OH⁻(aq)
C)HCO₃⁺(aq)and H₂O(aq)
D)HCO₃⁻(aq)and H⁻(aq)
E)HCO₃⁻(aq)and OH⁻(aq)

Question 39

When fluoride ion, F⁻, reacts with water, what are the products?

A)H⁺(aq)and OH⁻(aq)
B)F⁺(aq)and OH⁻(aq)
C)F⁺(aq)and H₂O(aq)
D)HF(aq)and H⁻(aq)
E)HF(aq)and OH⁻(aq)

Question 40

When sodium hydroxide, NaOH, is dissolved in water, which species are present in addition to water?

A)NaOH(aq)
B)Na⁺(aq)and OH⁻(aq)
C)Na⁺(aq)and H₃O⁻(aq)
D)Na⁺(aq)and O₂H₂²⁻(aq)
E)NaO⁻(aq)and H₃O⁺(aq)

Question 41

Select the strong acid from the following list.

A)H₃PO₄(aq)
B)CH₃CO₂H(aq)
C)H₂S(aq)
D)H₂SO₄(aq)
E)HF(aq)

Question 42

Select the strong acid from the following list.

A)HNO₃(aq)
B)HClO₃(aq)
C)HF(aq)
D)H₃PO₄(aq)
E)HCN(aq)

Question 43

Which of the following ions is amphoteric?

A)Cl⁻
B)OH⁻
C)H⁺
D)NO₃^-
E)HCO₃^-

Question 44

All of the following species are weak bases except:

A)KCN(aq)
B)NaNO₂(aq)
C)LiCl(aq)
D)C₆H₅NH₂(aq)
E)CH₃CH₂NH₂(aq)

Question 45

The image shows a molecular-level representation of part of a solution after HF is dissolved in water. (Besides water, there are 6 HF molecules, 1 H₃O⁺ ion, and 1 F⁻ ion present in the solution.)Which of the following best describes HF?

A)strong acid
B)strong base
C)weak acid
D)weak base
E)amphoteric

Question 46

Which of the following is the strongest acid?

A)HF, K_a = 6.3 × 10^-4
B)HCN, K_a = 6.2 × 10⁻¹⁰
C)HOCl, K_a = 4.0 × 10⁻⁸
D)CH₃CO₂H, K_a = 1.8 × 10⁻⁵
E)HCO₂H, K_a = 1.8 × 10⁻⁴

Question 47

Which of the following is an amphoteric substance?

A)NaOH
B)LiCl
C)CsBr
D)H₂O
E)CH₄

Question 48

Match the molecular-level diagrams to each of the following compounds in aqueous solution: HCl, HF, NH₃

A)I = HCl, II = HF, III = NH₃
B)I = HF, II = HCl, III = NH₃
C)I = HF, II = NH₃, III = HCl
D)I = NH₃, II = HF, III = HCl
E)I = NH₃, II = HCl, III = HF

Question 49

All of the following species are weak bases except:

A)NH₃(aq)
B)Na₂CO₃(aq)
C)KF(aq)
D)CH₃NH₂(aq)
E)NH₄Cl(aq)

Question 50

Select the strong acid from the following list.

A)H₂SO₃(aq)
B)H₂C₂O₄(aq)
C)H₂S(aq)
D)HNO₂(aq)
E)HI(aq)

Question 51

The H₂PO₄^- ion is amphoteric. What are the conjugate acid and conjugate base, in that order, of H₂PO₄^-?

A)PO₄^3-, H₂PO₄^-
B)H₂PO₄^-, PO₄^3-
C)H₂PO₄^-, H₃PO₄
D)H₃PO₄, HPO₄^2-
E)H₃O⁺, PO₄^3-

Question 52

The bicarbonate ion, HCO₃^-, is amphoteric. What are the conjugate acid and conjugate base, in that order, of HCO₃^-?

A)CO₃^2-, HCO₃^-
B)HCO₃^-, CO₃^2-
C)CO₃^2-, H₂CO₃
D)H₂CO₃, CO₃^2-
E)H₃O⁺, CO₃^2-

Question 53

All of the following species are weak bases except:

A)NaCN(aq)
B)K₂CO₃(aq)
C)KOH(aq)
D)CH₃NH₂(aq)
E)NH₃(aq)

Question 54

Which of the following equations represents the behavior of HCO₃− as an acid?

A)HCO₃⁻(aq)+ H₃O+(aq)⇌ H₂CO₃(aq)+ H₂O(l)
B)HCO₃⁻(aq)+ HF(aq)⇌ H₂CO₃(aq)+ F⁻(aq)
C)HCO₃⁻(aq)+ HCN(aq)⇌ H₂CO₃(aq)+ CN⁻(aq)
D)HCO₃⁻(aq)+ OH⁻(aq)⇌ CO₃²⁻(aq)+ H₂O(l)
E)HCO₃⁻(aq)+ H₂O(l)⇌ H₂CO₃(aq)+ OH⁻(aq)

Question 55

The image shows a molecular-level representation of part of a solution after ammonia, NH₃, is dissolved in water. (Besides water, there are 2 NH₄⁺ ions, 6 NH₃ molecules, and 2 OH⁻ ions present in the solution.). Which of the following best describes NH₃?

A)strong acid
B)strong base
C)weak acid
D)weak base
E)amphoteric

Question 56

Which of the following equations represents the behavior of H₂PO₄^- as a base?

A)H₂PO₄^-(aq)+ H₃O⁺(aq)⇌ H₃PO₄(aq)+ H₂O(l)
B)H₂PO₄^-(aq)+ F^-(aq)⇌ HPO₄^2-(aq)+ HF(aq)
C)H₂PO₄^-(aq)+ CN^-(aq)⇌ HPO₄^2-(aq)+ HCN(aq)
D)H₂PO₄^-(aq)+ OH^-(aq)⇌ HPO₄^2-(aq)+ H₂O(l)
E)H₂PO₄^-(aq)+ H₂O(l)⇌ H₃PO₄(aq)+ H₃O⁺(aq)

Question 57

Which of the following ions is amphoteric?

A)Br⁻
B)H⁻
C)OH⁺
D)SO₄²⁻
E)HPO₄²⁻

Question 58

Which of the following equations represents the behavior of H₂PO₄^- as an acid?

A)H₂PO₄^-(aq)+ H₃O⁺(aq)⇌ H₃PO₄(aq)+ H₂O(l)
B)H₂PO₄^-(aq)+ HF(aq)⇌ H₃PO₄(aq)+ F^-(aq)
C)H₂PO₄^-(aq)+ HCN(aq)⇌ H₃PO₄(aq)+ CN^-(aq)
D)H₂PO₄^-(aq)+ OH^-(aq)⇌ HPO₄^2-(aq)+ H₂O(l)
E)H₂PO₄^-(aq)+ H₂O(l)⇌ H₃PO₄(aq)+ OH^-(aq)

Question 59

The image shows a molecular-level representation of part of a solution after HCl is dissolved in water. What best describes this image? (Besides water, there are 6 H₃O⁺ ions and 6 Cl⁻ ions present in the solution.)Which of the following best describes HCl?

A)strong acid
B)strong base
C)weak acid
D)weak base
E)amphoteric

Question 60

Which of the following equations represents the behavior of HCO₃⁻ as a base?

A)HCO₃⁻(aq)+ H₃O+(aq)⇌ H₂CO₃(aq)+ H₂O(l)
B)HCO₃⁻(aq)+ F⁻(aq)⇌ CO₃²⁻(aq)+ HF(aq)
C)HCO₃⁻(aq)+ CN⁻(aq)⇌ CO₃²⁻(aq)+ HCN(aq)
D)HCO₃⁻(aq)+ OH⁻(aq)⇌ CO₃²⁻(aq)+ H₂O(l)
E)HCO₃⁻(aq)+ H₂O(l)⇌ H₂CO₃(aq)+ H₃O⁺(aq)

Question 61

The K_a for formic acid is 1.8 × 10^-4. Which of the following statements best describes the pH of a 0.0010 M solution of formic acid?

A)The pH is greater than 0 but less than 3.
B)The pH is exactly 3.
C)The pH is greater than 3 but less than 7.
D)The pH is exactly 7.
E)The pH is greater than 7 but less than 11.

Question 62

List the species present in order of increasing concentration in a 0.1 M solution of H₂Se.

A)H₂Se < HSe- < Se²⁻
B)H₂Se < Se²⁻ < HSe⁻
C)Se^2- < HSe- < H₂Se
D)HSe- < Se^2- < H₂Se
E)Se²⁻ < H₂Se < HSe⁻

Question 63

Select the solution below that is the most acidic.

A)[OH^-] = 1.0 × 10^-4 M
B)[OH^-] = 1.0 × 10^-5 M
C)[OH^-] = 1.0 × 10^-7 M
D)[OH^-] = 1.0 × 10^-9 M
E)[OH^-] = 1.0 × 10^-11 M

Question 64

Select the solution below that is the most basic.

A)[H₃O⁺] = 1.0 × 10^-4 M
B)[H₃O⁺] = 1.0 × 10^-6 M
C)[H₃O⁺] = 1.0 × 10^-7 M
D)[H₃O⁺] = 1.0 × 10^-8 M
E)[H₃O⁺] = 1.0 × 10^-10 M

Question 65

Select the solution below that is the most basic.

A)[OH^-] = 1.0 × 10^-4 M
B)[OH^-] = 1.0 × 10^-5 M
C)[OH^-] = 1.0 × 10^-7 M
D)[OH^-] = 1.0 × 10^-9 M
E)[OH^-] = 1.0 × 10^-11 M

Question 66

Which of the following ionizes to the greatest extent?

A)HNO₂, K_a = 5.6 × 10⁻⁴
B)HCN, K_a = 6.2 × 10⁻¹⁰
C)NH₄⁺, KK_a = 5.6 × 10⁻¹⁰
D)CH₃CO₂H, K_a = 1.8 × 10⁻⁵
E)HCO₂H, K_a = 1.8 × 10⁻⁴

Question 67

List the species present in order of increasing concentration in a 0.1 M solution of H₂S.

A)H₂S < HS^- < S^2-
B)H₂S < S^2- < HS^-
C)S^2- < HS^- < H₂S
D)HS^- < S^2- < H₂S
E)S^2- < H₂S < HS^-

Question 68

Which of the following ionizes to the greatest extent?

A)HF, K_a = 6.3 × 10⁻⁴
B)HCN, K_a = 6.2 × 10⁻¹⁰
C)HOCl, K_a = 4.0 × 10⁻⁸
D)CH₃CO₂H, K_a = 1.8 × 10⁻⁵
E)HCO₂H, K_a = 1.8 × 10⁻⁴

Question 69

Given 0.10 M solutions of the following acids, which contains the highest concentration of H₃O⁺?

A)HF, K_a = 6.3 × 10⁻⁴
B)HCN, K_a = 6.2 × 10⁻¹⁰
C)HOCl, K_a = 4.0 × 10⁻⁸
D)CH₃CO₂H, K_a = 1.8 × 10⁻⁵
E)HCO₂H, K_a = 1.8 × 10⁻⁴

Question 70

Select the solution below that is the most acidic.

A)[H₃O⁺] = 1.0 × 10^-4 M
B)[H₃O⁺] = 1.0 × 10^-6 M
C)[H₃O⁺] = 1.0 × 10^-7 M
D)[H₃O⁺] = 1.0 × 10^-8 M
E)[H₃O⁺] = 1.0 × 10^-10 M

Question 71

Rank the following 0.100 M solutions in order of increasing H₃O⁺ concentration: HF, K_a = 6.3 × 10⁻⁴; HCN, K_a = 6.2 × 10⁻¹⁰; HOCl, K_a = 4.0 × 10⁻⁸

A)HF < HCN < HOCl
B)HF < HOCl < HCN
C)HOCl < HF < HCN
D)HOCl < HCN < HF
E)HCN < HOCl < HF

Question 72

The K_a for acetic acid is 1.8 × 10^-5. Which of the following statements best describes the pH of a 0.010 M solution of acetic acid?

A)The pH is greater than 0 but less than 2.
B)The pH is exactly 2.
C)The pH is greater than 2 but less than 7.
D)The pH is exactly 7.
E)The pH is greater than 7 but less than 12.

Question 73

Given 0.10 M solutions of the following acids, which contains the highest concentration of H₃O⁺?

A)HNO₂, K_a = 5.6 × 10⁻⁴
B)HCN, K_a = 6.2 × 10⁻¹⁰
C)NH₄⁺, K_a = 5.6 × 10⁻¹⁰
D)CH₃CO₂H, K_a = 1.8 × 10⁻⁵
E)HCO₂H, K_a = 1.8 × 10⁻⁴

Question 74

Given 0.10 M solutions of the following acids, which contains the lowest concentration of H₃O⁺?

A)HF, K_a = 6.3 × 10⁻⁴
B)HCN, K_a = 6.2 × 10⁻¹⁰
C)HOCl, K_a = 4.0 × 10⁻⁸
D)CH₃CO₂H, K_a = 1.8 × 10⁻⁵
E)HCO₂H, K_a = 1.8 × 10⁻⁴

Question 75

Rank the following 0.100 M solutions in order of increasing H₃O⁺ concentration: HOCl, K_a = 4.0 × 10⁻⁸; HCN, K_a = 6.2 × 10⁻¹⁰; NH₄⁺, K_a = 5.6 × 10⁻¹⁰

A)HOCl < HCN < NH₄⁺
B)HOCl < NH₄⁺ < HCN
C)HCN < NH₄⁺ < HOCl
D)HCN < HOCl < NH₄⁺
E)NH₄⁺ < HCN < HOCl

Question 76

Which of the following is the strongest acid?

A)HOCl, K_a = 4.0 × 10⁻⁸
B)HCN, K_a = 6.2 × 10⁻¹⁰
C)NH₄⁺, K_a = 5.6 × 10⁻¹⁰
D)CH₃CO₂H, K_a = 1.8 × 10⁻⁵
E)HCO₂H, K_a = 1.8 × 10⁻⁴

Question 77

Which of the following is the strongest acid?

A)HNO₂, K_a = 5.6 × 10⁻⁴
B)HCN, K_a = 6.2 × 10⁻¹⁰
C)NH₄⁺, K_a = 5.6 × 10⁻¹⁰
D)CH₃CO₂H, K_a = 1.8 × 10⁻⁵
E)HCO₂H, K_a = 1.8 × 10⁻⁴

Question 78

Rank the following 0.100 M solutions in order of increasing H₃O⁺ concentration: HCN, K_a = 6.2 × 10^-10; NH₄+, K_a = 5.6 × 10^-10; CH₃CO₂H, K_a = 1.8 × 10^-5

A)HCN < NH₄⁺ < CH₃CO₂H
B)HCN < CH₃CO₂H < NH₄⁺
C)CH₃CO₂H < NH₄⁺ < HCN
D)CH₃CO₂H < HCN < NH₄⁺
E)NH₄⁺ < HCN < CH₃CO₂H

Question 79

List the species present in order of increasing concentration in a 0.1 M solution of H₂C₂O₄.

A)H₂C₂O₄ < HC₂O₄⁻ < C₂O₄²⁻
B)H₂C₂O₄ < C₂O₄²⁻ < HC₂O₄⁻
C)C₂O₄²⁻ < HC₂O₄⁻ < H₂C₂O₄
D)HC₂O₄⁻ < C₂O₄²⁻ < H₂C₂O₄
E)C₂O₄²⁻ < H₂C₂O₄ < HC₂O₄⁻

Question 80

Select the solution below that is the most acidic.

A)[OH^-] = 1.0 × 10^-4 M
B)[OH^-] = 1.0 × 10^-5 M
C)[H₃O⁺] = 1.0 × 10^-6 M
D)[H₃O⁺] = 1.0 × 10^-8 M
E)[H₃O⁺] = 1.0 × 10^-10 M