Deck 15: Electrolytes, Acids, and Bases

Question 1

What is the pH of an aqueous solution having a hydrogen-ion concentration of 6.83 × 10^-3 mol/L?

A)6.831
B)0.834
C)2.166
D)1.029

Answer 1

2.166

Question 2

Which of the following produces only one H₃O⁺ ion per molecule of acid when dissolved in water, although itself has other non-ionizable hydrogens?

A)hydrobromic
B)sulfurous
C)hypochlorous
D)acetic

Answer 2

acetic

Question 3

Which of the following does not produce more than one H₃O⁺ ion per molecule of acid when dissolved in water?

A)carbonic
B)sulfurous
C)phosphoric
D)acetic

Answer 3

acetic

Question 4

Which of the following could be considered an Arrhenius base?

A)HCl
B)CH₃COOH
C)KOH
D)HF

Question 5

The compound HA is an acid that is soluble in water. Which of the "beakers" below shows HA behaving as a weak acid in water?

A)

B)

C)

D)Both A and C are weak acids in water.

Question 6

Which of the following solutions would you expect not to conduct electricity?

A)NaCl in water
B)CO in water
C)HCl in water
D)H₂SO₄ in water

Question 7

Which of the following is a triprotic acid when dissolved in water?

A)hydrobromic
B)sulfuric
C)hypochlorous
D)phosphoric

Question 8

Which of the following is a strong electrolyte when dissolved in distilled water?

A)sodium chloride
B)sucrose
C)acetone (nail polish remover)
D)ethyl alcohol

Question 9

Which of the following is a weak electrolyte when dissolved in distilled water?

A)phosphoric acid
B)nitric acid
C)potassium chloride
D)glucose

Question 10

What is the hydroxide-ion concentration of an aqueous solution having a pH of 4.72?

A)4.7 × 10^-5 mol/L
B)1.9 × 10^-14 mol/L
C)5.3 × 10^-10 mol/L
D)1.9 × 10^-5 mol/L

Question 11

What is the hydrogen-ion concentration of an aqueous solution having a pH of 4.72?

A)4.7 × 10^-5 mol/L
B)4.7 mol/L
C)0.67 mol/L
D)1.9 × 10^-5 mol/L

Question 12

Which of the following is a non-electrolyte when dissolved in distilled water?

A)sodium chloride
B)hydrochloric acid
C)sodium hydroxide
D)ethyl alcohol

Question 13

Which of the following could be considered an Arrhenius acid?

A)HCl
B)CH₃COOH
C)NH₄⁺
D)All of the above are Arrhenius acids.

Question 14

Which of the following is not a strong electrolyte when dissolved in distilled water?

A)potassium chloride
B)sulfuric acid
C)acetic acid
D)potassium hydroxide

Question 15

What is the hydroxide-ion concentration of an aqueous solution having a hydrogen-ion concentration of 4.75 × 10^-5 mol/L?

A)2.10 × 10^-10 mol/L
B)5.25 × 10^-10 mol/L
C)4.75 × 10^-5 mol/L
D)-4.75 × 10^-5 mol/L

Question 16

Which of the following is not a weak electrolyte when dissolved in distilled water?

A)ammonia
B)acetic acid (vinegar)
C)potassium chloride
D)hydrogen fluoride

Question 17

The compound HA is an acid that is soluble in water. Which of the "beakers" below shows HA behaving as a strong acid in water?

A)

B)

C)

D)

Question 18

Which of the following conjugate pairs would form a good buffer?

A)HCl/Cl^-
B)OH^-/H₂O
C)NH₃/NH₄⁺
D)HNO₃/NO₃^-

Question 19

Which of the following is a diprotic acid when dissolved in water?

A)hydrobromic
B)sulfuric
C)hypochlorous
D)phosphoric

Question 20

Which of the following produces more than one H₃O⁺ ion per molecule of acid when dissolved in water?

A)hydrobromic
B)carbonic
C)hypochlorous
D)acetic

Question 21

The pH of natural rainwater is close to ________.

A)5.6
B)6.3
C)7.0
D)8.2

Question 22

Which of the following qualifies as a Bronsted-Lowry base?

A)CH₄
B)NH₃
C)SiH₄
D)H₂

Question 23

A change in pH from 10 to 7 ________.

A)increases the acidity 1000×
B)reduces the acidity 3000×
C)increases the acidity 3×
D)increases the acidity 3000×

Question 24

Which is a weak acid?

A)sulfuric
B)hydrochloric
C)nitric
D)carbonic

Question 25

The conjugate base of H₂PO₄^- is ________.

A)H₃PO₄
B)HPO₄^-2
C)PO₄^-3
D)H₄PO₄⁺

Question 26

Acidic solutions ________.

A)have a higher concentration of hydronium ions than hydroxide ions
B)have a lower concentration of hydronium ions than hydroxide ions
C)turn red litmus paper to blue
D)colorize phenolphthalein solutions

Question 27

Which of the following produces two OH^- ions per molecule of base when dissolved in water?

A)potassium hydroxide
B)calcium hydroxide
C)aluminum hydroxide
D)ammonia

Question 28

Which of the following qualifies as a Bronsted-Lowry acid?

A)KOH
B)NH₃
C)Na⁺
D)NH₄⁺

Question 29

Which of the following does not qualify as a Bronsted-Lowry base?

A)CH₄
B)NH₃
C)PH₃
D)H₂O

Question 30

The pH of blood is approximately ________.

A)5.2
B)7.0
C)7.4
D)9.1

Question 31

Basic solutions ________.

A)have a higher concentration of hydronium ions than hydroxide ions
B)have a lower concentration of hydronium ions than hydroxide ions
C)turn blue litmus paper to pink
D)decolorize phenolphthalein solutions

Question 32

Which of the following is a strong acid?

A)acetic acid
B)hydrofluoric acid
C)phosphoric acid
D)hydrochloric acid

Question 33

The conjugate base of ammonia is ________.

A)NH₂^-
B)NH^-
C)N^-3
D)NH₄⁺

Question 34

Which of the following can behave both as a Bronsted-Lowry acid and a Bronsted-Lowry base?

A)CH₄
B)H₂O
C)SiH₄
D)H₂

Question 35

The conjugate acid of H₂PO₄^- is ________.

A)H₃PO₄
B)HPO₄^-2
C)PO₄^-3
D)H₄PO₄⁺

Question 36

When ammonia is dissolved in water, the ionized species are ________.

A)NH₄⁺ and OH^-
B)NH₂^- and H⁺
C)NH₄⁺ and H^-
D)NH₂⁺ and H^-

Question 37

Stomach juices have a pH close to ________.

A)1.5
B)2.8
C)4.5
D)7.0

Question 38

The conjugate base of HCO₃^- is ________.

A)H₂CO₃
B)CO₃^-2
C)CO₂^-2
D)H₃CO₃⁺

Question 39

A drop of a full unit in the pH scale ________.

A)reduces the acidity 10×
B)increases the acidity 10×
C)reduces the acidity 2×
D)increases the acidity 2×

Question 40

Which of the following produces only one OH^- ion per molecule of base when dissolved in water?

A)potassium hydroxide
B)calcium hydroxide
C)aluminum hydroxide
D)barium hydroxide

Question 41

Which is the most acidic solution?

A)a solution whose [H⁺] = 10^-1
B)a solution whose [OH^-] = 10^-10
C)a solution whose pH = 0
D)All of the above have the same degree of acidity.

Question 42

A concentrated solution of a non-electrolyte such as glucose can be made to conduct electricity.

Question 43

Sodium chloride (NaCl)is considered an electrolyte because it dissolves in water into positive and negative ions.

Question 44

Which of the following is the weakest acid?

A)acetic acid, K_a = 1.8 × 10^-5
B)nitrous acid, K_a = 4.5 × 10^-4
C)hydrogen peroxide, K_a = 2.4 × 10^-12
D)hypochlorous acid, K_a = 3.5 × 10^-8

Question 45

In a solution of a strong acid in water, the hydrogen-ion concentration is approximately equal to the molarity of the acid.

Question 46

What are the ions formed in glucose, C₆H₁₂O₆ ?

A)C₆H₁₁O₆^- + H⁺
B)C₆H₁₁O₅⁺ + OH^-
C)CO₂ + H₂O
D)No ions are formed.

Question 47

Which of the following is the weakest base?

A)ammonia, K_b = 1.7 × 10^-5
B)aniline, K_b = 4.2 × 10^-10
C)trimethylamine, K_b = 7.4 × 10^-5
D)methylamine, K_b = 4.4 × 10^-4

Question 48

Which substance is the most acidic?

A)coffee
B)milk
C)oven cleaner
D)baking soda

Question 49

The compound HCl is considered a Bronsted-Lowry base because it increases the concentration of H₃O⁺ when it dissociates in water.

Question 50

Which is a strong base?

A)potassium hydroxide
B)ammonium hydroxide
C)aluminum hydroxide
D)fluoride ion

Question 51

The base in the forward reaction NH₃ + H₂O → NH₄⁺ + OH^- is ________.

A)NH₄⁺
B)H₂O
C)NH₃
D)OH^-

Question 52

The hydrogen-ion concentration of a solution of pOH 10.5 is 3.16 × 10^-4 mol/L (remember that pH + pOH = 14 for aqueous systems).

Question 53

The autodissociation of water gives pure water a pH of 4 and thus a higher concentration of H₃O⁺ than OH^-.

Question 54

An aqueous solution of pOH 5 is more basic than an aqueous solution of pOH 8.

Question 55

Which is the most basic solution?

A)a solution whose [H⁺] = 10⁰
B)a solution whose [OH^-] = 10^-14
C)a solution whose pH = 0
D)All of the above have the same degree of basicity.

Question 56

"Buffered" solutions are resistant to pH changes, even when small amounts of strong acid or base are added to them.

Question 57

Which of the following is the strongest acid?

A)acetic acid, K_a = 1.8 × 10^-5
B)nitrous acid, K_a = 4.5 × 10^-4
C)hydrogen peroxide, K_a = 2.4 × 10^-12
D)hypochlorous acid, K_a = 3.5 × 10^-8

Question 58

The acid in the forward reaction HCO₃^- + H₂O → H₂CO₃ + OH^- is ________.

A)HCO₃^-
B)H₂O
C)H₂CO₃
D)OH^-

Question 59

The carbonate (CO₃^2-)/bicarbonate (HCO₃^-)pair represents a base and its conjugate acid.

Question 60

Which of the following is a weak base?

A)sodium hydroxide
B)ammonium hydroxide
C)lithium hydroxide
D)potassium hydroxide

Question 61

A saline solution will not conduct an electric current.

Question 62

H₂PO₄^- is the conjugate acid of PO₄^2-.

Question 63

PH₃ cannot be described as a Bronsted-Lowry base.

Question 64

A solution of HCl/Cl^- can act as a buffer.

Question 65

CH₃CO₂H has four acidic hydrogens.

Question 66

Solid sodium chloride is a strong electrolyte.

Question 67

Water can serve both as a Bronsted-Lowry acid and Bronsted-Lowry base.

Question 68

Milk's pH is slightly basic.

Question 69

Sulfuric acid is a diprotic acid.

Question 70

Deionized water can conduct electricity.

Question 71

Approximately one out of every 555 million water molecules autoionize.

Question 72

Hydrochloric, hypochlorous and hydrobromic acids produce only one H₃O⁺ ion per molecule of acid when dissolved in water.

Question 73

Carbonic, phosphoric, and sulfuric acids produce two H₃O⁺ ions per molecule of acid when dissolved in water.

Question 74

Sucrose (table sugar)is a strong electrolyte.

Question 75

An electrolyte is a substance that, when dissolved in water, yields a solution that conducts electric current.

Question 76

Aqueous salt solution is a strong electrolyte.

Question 77

Arrhenius' definition of a base is an electrolyte that contains a metal and hydroxide ions that ionize when placed in water.

Question 78

An aqueous solution of HCl is called hydrochloric acid.

Question 79

The pH of natural rainwater is 5.6 due to the carbon dioxide in the atmosphere.

Question 80

Sodium hydroxide is a non-electrolyte.