Deck 11: Acids and Bases

Question 1

Heartburn is caused by

A) a heart attack.
B) ingestion of acid.
C) acid in the stomach.
D) bBackflow of acid into the esophagus.

Answer 1

D

Question 2

Which of the following acids are an inorganic acid?

A) lactic acid
B) ascorbic acid
C) acetic acid
D) sulfuric acid

Answer 2

D

Question 3

Which of the following is not a base?

A) sodium hydroxide
B) sodium chloride
C) sodium carbonate
D) sodium bicarbonate

Answer 3

B

Question 4

Which of the following reactions describes the Brønsted-Lowry behavior of perchloric acid, HClO₄?

A) HClO₄(aq) + H₂O(l)  OH-(aq) + H₂ClO₄+aq)
B) HClO₄(aq) + H₂O(l)  H₃O⁺(aq) + ClO₄^-(aq)
C) HClO₄(aq) + H₂O(l)  H₃O⁺(aq) + ClO₂^-(aq) + O₂(g)
D) 2 HClO₄(aq) + H₂O(l)  H₄O²⁺(aq) + 2ClO₄^-(aq)

Question 5

In the Brønsted-Lowry model the acid

A) donates an OH.
B) accepts a H⁺.
C) donates a H⁺.
D) accepts an OH^.

Question 6

Which of the following is a hydronium ion?

A) H⁺
B) OH^-
C) H₄O²⁺
D) H₃O⁺

Question 7

Which of the following may be a Brønsted-Lowry base?

A) KOH
B) H₂O
C) NH3
D) all of the above

Question 8

Which of the following common drugs acts as a Brønsted-Lowry base?

A)
B)
C)
D)

Question 9

Which of the following reactions shows the Brønsted-Lowry base dissociation of sodium hydroxide?

A) NaOH(aq) + H2O(l)  Na⁺(aq) + OH^-(aq) + H2O(l)
B) KOH(s)  K+(aq) + OH^-(aq)
C) NaOH(aq) + H⁺(aq)  NaOH₂⁺(aq)
D) NaOH(aq) + OH^-(aq)  Na(OH)₂^-(aq)

Question 10

What is the net ionic equation for the reaction of nitric acid, HNO₃, and potassium hydroxide, KOH?

A) HNO₃(aq) + KOH(aq)  H₂O(l) + KNO₃(aq)
B) H⁺(aq) + NO₃^-(aq) + K⁺(aq) + OH^-(aq)  H₂O(l) + NO₃^-(aq) + K⁺(aq)
C) H⁺(aq) + OH-(aq)  H₂O(l)
D) HNO₃(aq) + KOH(aq)  H₂O(l) + K⁺(aq) + NO₃^-(aq)

Question 11

Balance the equation for the neutralization of aluminum hydroxide, Al(OH)₃, with HCl.

A) Al(OH)₃(aq) + HCl(aq)  H₂O(l) + AlCl₃(aq)
B) Al(OH)₃(aq) + 2HCl(aq)  2H₂O(l) + AlCl₃(aq)
C) Al(OH)₃(aq) + 3HCl(aq)  3H₂O(l) + AlCl₃(aq)
D) Al(OH)₃(aq) + 4HCl(aq)  4H₂O(l) + AlCl₃(aq)

Question 12

Balance the equation for the neutralization of calcium hydroxide, Ca(OH)₂, and sulfuric acid, H₂SO₄.

A) Ca(OH)₂(aq) + H₂SO₄(aq)  2H₂O(l) + CaSO₄(s)
B) Ca(OH)₂(aq) + 2H₂SO₄(aq)  2H₂O(l) + CaSO₄(s)
C) 2Ca(OH)₂(aq) + H₂SO₄(aq)  2H₂O(l) + CaSO₄(s)
D) 3Ca(OH)₂(aq) + 2H₂SO₄(aq)  H₂O(l) + CaSO₄(s)

Question 13

Nitric acid is a strong acid and dissociates in water. What species are present in the aqueous solution of 0.1 M HNO₃?

A) HNO₃ only
B) primarily HNO₃ but some H₃O⁺ and NO₃^-
C) primarily H₃O⁺ and NO₃^- but some HNO₃
D) H₃O⁺ and NO₃^- only

Question 14

Lactic acid, CH₃CH(OH)CO₂H, is a weak acid that dissociates in water according to the equation CH₃CH(OH)CO₂H(aq) + H₂O(l)  CH₃CH(OH)CO₂^-(aq) + H₃O⁺(aq). What species are in the aqueous solution of 0.1 M lactic acid?

A) CH₃CH(OH)CO₂H only
B) CH₃CH(OH)CO₂H primarily but some H₃O⁺ and CH₃CH(OH)CO₂^-
C) H₃O⁺ and CH₃CH(OH)CO₂^- only
D) H₃O⁺ and CH₃CH(OH)CO₂^- primarily but some CH₃CH(OH)CO₂H

Question 15

A solution of an acid exhibits very good electrical conductivity. It is a

A) weak acid.
B) strong acid.
C) covalent molecule.
D) all of the above

Question 16

Which of the solutions below will be highly conductive of electricity?

A) 0.1 M acetic acid, CH₃CO₂H
B) 0.1 M formic acid, CHO₂H
C) 0.1 M hydrochloric acid, HCl
D) 0.1 M lactic acid, CH₃CH(OH)CO₂H

Question 17

Which of the following is a true statement about an aqueous solution of a base when describing it as strong?

A) It is a good conductor of electricity.
B) Much of the unionized base exists in the solution.
C) It is a poor conductor of electricity.
D) none of the above

Question 18

The acidity of formic acid, CHO₂H, results from

A) CHO₂H.
B) CHO₂.
C) H₂O.
D) H₃O⁺.

Question 19

The conjugate base of HCl is

A) H₂Cl⁺.
B) OH^.
C) H₃O⁺.
D) Cl.

Question 20

What is the conjugate base of ammonium, NH₄⁺?

A) OH
B) H₂O
C) NH₃
D) NH₅²⁺

Question 21

What are the relative proportions of reactants to products for the dissociation of the weak base trimethylamine? (CH₃)₃N(aq) + H₂O(l)  (CH₃)₃NH⁺(aq) + OH^-(aq)

A) The reaction consists of 100% of the reactant (CH₃)₃N.
B) The reaction consists of some of the reactant (CH₃)₃N but mostly the products (CH₃)₃NH⁺ and OH.
C) The reaction consists of mostly the reactant (CH₃)₃N but some of the products (CH₃)₃NH⁺ and OH.
D) The reaction consists of 100% of the products (CH₃)₃NH⁺ and OH.

Question 22

The bisulfite ion (HSO₃^-) is a weak acid. What is the missing species in the reversible dissociation of bisulfite in aqueous solution? HSO₃^-(aq) + H₂O(l)  H₃O⁺(aq) + ?

A) SO₃^2-
B) H₂SO₃
C) H₂S + O₂
D) SO₂ + O₂

Question 23

What is the concentration of H₃O⁺ ion in pure water?

A) 1  10^-14 M
B) 2  10^-14 M
C) 1  10⁷ M
D) 1  10^-7 M

Question 24

What is the concentration of OH^- ion in pure water?

A) 1  10^-14 M
B) 2  10^-14 M
C) 1  10⁷ M
D) 1  10^-7 M

Question 25

At 25°C the term [H₃O⁺][OH^-] equals

A) 1  10^-7.
B) 2  10^-14.
C) 1  10¹⁴.
D) 1  10^-14.

Question 26

In pure water which is in greater concentration H₃O⁺ or OH^-?

A) [H₃O⁺] > [OH^-]
B) [H₃O⁺] < [OH^-]
C) [H₃O⁺] = [OH^-]
D) It varies depending upon temperature.

Question 27

In a dilute solution of base at 25°C, the concentration of H₃O⁺ is 1  10^-9 M. Calculate the concentration of OH^- ions.

A) 1  10^-9 M
B) 1  10^-7 M
C) 1  10^-5 M
D) 1  10^-2 M

Question 28

In a dilute solution of acid at 25°C, the concentration of H₃O⁺ is 1  10^-3 M. What is the concentration of OH^- ions?

A) 1  10¹¹ M
B) 1  10^-4 M
C) 1  10^-7 M
D) 1  10^-11 M

Question 29

Which of the following solutions is acidic?

A) [OH^-] = 1  10^-8 M
B) [OH^-] = 1  10^-7 M
C) [OH^-] = 1  10^-5 M
D) [OH^-] = 1  10^-2 M

Question 30

Which of the following solutions is basic?

A) [H₃O⁺] = 1  10^-8 M
B) [H₃O⁺] = 1  10^-7 M
C) [H₃O⁺] = 1  10^-5 M
D) [H₃O⁺] = 1  10^-3 M

Question 31

At 25°C the concentration of H₃O⁺ in a solution is 1  10^-2 M. What is the pH?

A) -2
B) 0.5
C) 0.01
D) 2

Question 32

At 25°C the concentration of OH^- in a solution is 1  10^-8 M. What is the pH of the solution?

A) 8
B) 6
C) -8
D) -6

Question 33

Milk has a H₃O⁺ concentration of 1  10^-6 M. What is the pH of the milk?

A) 5
B) 6
C) 7
D) 8

Question 34

Perchloric acid (HClO₄) is a strong acid. What is the pH of a 0.0001 M solution of this acid?

A) 4
B) 3
C) 5
D) 7

Question 35

Black coffee has a pH of 5.0. What is the concentration of H₃O⁺ in the coffee?

A) 1  10^-5 M
B) 1  10^-9 M
C) 1  10^-7 M
D) 1  10^-11 M

Question 36

Lemon juice has a pH of 2.0. What is the concentration of H₃O⁺ in the juice?

A) 1  10^-2 M
B) 1  10^-7 M
C) 1  10^-5 M
D) 1  10^-12 M

Question 37

What is most important in the release of gastric acid in the stomach?

A) histamine
B) H2 receptor
C) proton pump
D) H2 receptor blockers

Question 38

Which of the following drugs is responsible for reducing the production of acid in the stomach?

A) antacid
B) histamine
C) H2 receptor blockers
D) proton pump

Question 39

Acid reflux disease (GERD) is caused by

A) generation of acid in the esophagus.
B) flow of acid from the esophagus to the stomach.
C) flow of acid from the stomach to the esophagus.
D) acid inflaming the stomach lining.

Question 40

Acid is produced in the stomach by

A) histamine.
B) H2 receptors.
C) proton pump.
D) H. pylori.

Question 41

Which of the following mixtures of chemical substances would be a buffer?

A) HCO₃^- and H₂O
B) H₂CO₃ and H₂O
C) H₂CO₃ and HCO₃^-
D) HCO₃^- and H₃O⁺

Question 42

A carbonic acid (H₂CO₃) and bicarbonate (HCO₃^-) forms a buffer in the blood stream. Excess acid in the blood stream causes the

A) pH to rise dramatically.
B) carbonic acid to be consumed with very little change in pH.
C) bicarbonate to be consumed with very little change in pH.
D) pH to drop dramatically.

Question 43

A buffer could be prepared by mixing lactic acid with

A) HCl.
B) sodium acetate.
C) sodium lactate.
D) ammonium chloride.

Question 44

To produce a buffer from a weak acid, you would add

A) water.
B) its conjugate base.
C) another weak acid.
D) a salt.

Question 45

The mixture of a weak acid and its conjugate base produces

A) a salt.
B) a strong acid and strong base.
C) water.
D) a buffer.

Question 46

Individuals who experience frequent acid reflux have a condition called ____________________.

Question 47

Because acetic acid can dissociate into hydronium ion and acetate ion and then the acetate ion can accept a proton from a hydronium ion, the reaction is ____________________.

Question 48

Acetate is the ____________________ of acetic acid.

Question 49

When the relative amounts of reactant and product are in balance, the reaction has reached ____________________.

Question 50

The conjugate base of HSO₄^- is ____________________.

Question 51

A mixture of chemical substances that resists change in pH is a ____________________.

Question 52

The conjugate base of carbonic acid, H₂CO₃, is ____________________.

Question 53

Show the reaction that demonstrates trimethylamine, (CH₃)₃NH₂ as a Brønsted-Lowry base.

Question 54

Iron(III) ion, Fe³⁺ produces acidic aqueous solutions. Why can it not be a Brønsted-Lowry acid?

Question 55

Why is a weak acid, such as acetic acid, a weak conductor of electricity?

Question 56

Chloride, Cl-, is the conjugate base of the strong acid HCl. Acetate, CH₃CO₂^-, is the conjugate base of the weak acid acetic acid, CH₃CO₂H. What is the relative strength of these two bases? Explain your answer.

Question 57

What is the conjugate acid of OH^-? Describe and explain the relative strength of each.

Question 58

Describe the action of a carbonic acid (H₂CO₃) and bicarbonate (HCO₃^-) buffer when a base is introduced.

Question 59

Describe the action of a carbonic acid (H₂CO₃) and bicarbonate (HCO₃^-) buffer when an acid is introduced.

Question 60

How would you prepare a buffer?

Question 61

Describe the purpose of buffers in the blood stream.