Acids and Bases Test Questions & Answers Chapter 9

Test questions for Chapter 9

Acids and Bases

1. Ethylene glycol and propylene glycol are both

• 1. hydrocarbons.
  2. carboxylic acids.
  3. diols.
  4. ethers.
  5. toxic organic acids.

1. In the body, ethylene glycol (antifreeze) is metabolized to a(n)
   1. hydrocarbon.
   2. diol.
   3. ether.
   4. toxic organic acid.
   5. Ethylene glycol is not metabolized.
2. Which of the following statements about acids is NOT true?
   1. An example of an acid is HBr.
   2. An acid increases the concentration of hydroxide in solution.
   3. An acid increases the concentration of protons in solution.
   4. An acid increases the concentration of hydronium in solution.
   5. An acid is a proton donor.
3. Which of the following statements about bases is NOT true?
   1. A base decreases the concentration of hydronium in solution.
   2. An example of a base is Ca(OH)₂.
   3. A base increases the concentration of hydroxide in solution.
   4. A base is a proton acceptor.
   5. A base is always negatively charged.
4. Select the choice that correctly states whether the substance is an acid or a base.
   1. Vinegar is basic.
   2. Amines are basic.
   3. Gastric juice is basic.
   4. Sodium hydroxide is acidic.
   5. Morphine is acidic.
5. All acid-base reactions that we consider in this chapter occur in
   1. acidic solution.
   2. basic solution.
   3. neutral solution.
   4. water.
   5. nonpolar solvents.
6. Which of the following atomic diagrams best represents H⁺?

a. b. c. d. e.

+

-

+

+

-

+

+

-

-

+

1. A hydrogen atom without an electron is referred to as
   1. hydroxide.
   2. hydronium.
   3. a proton.
   4. an acid.
   5. a conjugate base.
2. According to the Arrhenius definition, which of the following compounds is a base?

Ca(OH)₂ HCl NaOH CH₃CH₂NH₂

I II III IV

• 1. I and III only
  2. I, II and IV
  3. All of these compounds
  4. III only
  5. IV only

1. Which of the following compounds is a Brønsted Lowry base, but not an Arrhenius base?
   1. HCl
   2. NaOH
   3. NH₃
   4. Ca(OH)₂
   5. CH₃COOH
2. Which of the following reactions best illustrates the reaction of an acid in aqueous solution?

1. Which of the following statements best describes what happens when an acid reacts with water?
   • • • 1. The acid donates a proton.
         2. Water donates a proton.
         3. Water acts as a base.
         4. Hydronium is formed.
         5. Hydroxide is formed.
2. I only
3. II only
4. I, III, and V
5. I, III, and IV
6. II and V
7. Not all protons in a molecule can be donated in an acid-base reaction. Below are three molecules, each with the proton donated in an acid-base reaction circled. What do these protons have in common?

• 1. They are all attached to oxygen.
  2. They are all in a carbon-containing molecule.
  3. They are all attached to the most electronegative atom in the molecule.
  4. They are the only hydrogens in the molecule.
  5. They are all attached to carbon.

1. Which of the following equations best describes what will happen to formic acid when it reacts with water?

1. Which of the following reactions illustrate the reaction of a base?
   • • • 1. NH₃ + H₂O → ⁺NH₄ + ⁻OH
         2. HCl + H₂O → H₃O⁺ + Cl⁻
         3. NaOH → Na⁺ + ⁻OH
         4. ⁺NH₄ + H₂O → H₃O⁺ + NH₃
2. I only
3. II only
4. I and III
5. I, III, and IV
6. All of the above are reactions of a base.
7. Which of the following molecules is a base?

a. b. c. d. e.

1. What do all bases have in common?
   1. They contain an ^–OH group.
   2. They contain a nitrogen.
   3. They contain an oxygen.
   4. They are salts.
   5. They contain a nonbonding pair of electrons.
2. Which of the following types of molecules and ions is NOT a base?
   1. an anion
   2. a cation
   3. a neutral molecule containing a nonbonding pair of electrons
   4. a tertiary nitrogen
   5. All of these are bases.
3. The boxed species in the following reaction is

NH₃ + H₂O → ⁺NH₄ + ⁻OH

1. hydroxide.
2. hydronium.
3. a proton.
4. the acid.
5. the base.
6. The boxed species in the following reaction is

NH₃ + H₂O → ⁺NH₄ + ⁻OH

1. hydroxide.
2. hydronium.
3. a proton.
4. the acid.
5. the base.
6. The boxed species in the following reaction is

H₂SO₄ + H₂O → HSO₄⁻ + H₃O⁺

• 1. hydroxide.
  2. hydronium.
  3. a proton.
  4. the acid.
  5. the conjugate base.

1. The boxed species in the following reaction is

H₂SO₄ + H₂O → HSO₄⁻ + H₃O⁺

• 1. hydroxide.
  2. hydronium.
  3. a proton.
  4. the acid.
  5. the conjugate base.

1. The boxed species in the following reaction is

H₂SO₄ + H₂O → HSO₄⁻ + H₃O⁺

• 1. hydroxide.
  2. hydronium.
  3. a proton.
  4. the acid.
  5. the base.

1. The following is the reaction of benzoic acid in water. Which of the following choices is a conjugate acid-base pair in this reaction?

benzoic acid benzoate

• 1. benzoic acid and water
  2. benzoate and hydronium
  3. benzoic acid and hydronium
  4. benzoic acid and benzoate
  5. benzoate and water

1. Which of the following statements best describes the behavior of water in the acid-base reaction between dopamine and water?

• 1. Water is the acid.
  2. Water is the base.
  3. Water is the conjugate acid.
  4. Water is the conjugate base.
  5. Water is both an acid and a base.

1. Which of the following are conjugate acid-base pairs in the acid-base reaction between dopamine and water?

• • • • 1. H₂O and
        2. H₂O and ^–OH
        3. and
        4. and ^–OH

1. I only
2. I and IV
3. II only
4. II and IV
5. II and III
6. When an acid is dissolved in water, it reacts to give _________ and ________.
7. hydroxide; hydronium
8. hydronium; the conjugate acid
9. hydroxide; the conjugate acid
10. hydronium; the conjugate base
11. hydroxide; the conjugate base
12. When a base is dissolved in water, it reacts to give _________ and ________.
13. hydroxide; hydronium
14. hydronium; the conjugate acid
15. hydroxide; the conjugate acid
16. hydronium; the conjugate base
17. hydroxide; the conjugate base
18. A conjugate acid-base pair is
    1. the reactants in an acid-base reaction.
    2. the products of an acid-base reaction.
    3. two species that differ only by a proton.
    4. two species that differ only by a hydroxyl group.
    5. a single molecule that can act as both an acid and a base.
19. Water can react as both an acid and a base, depending on its environment. Because of this characteristic, water is a(n) _________ molecule.
    1. amphoteric
    2. autonomous
    3. complex
    4. reactive
    5. conjugated
20. Which of the following molecules is amphoteric?
    1. CH₃NH₂
    2. CH₃OH
    3. CH₃COOH
    4. H₂SO₄
    5. NaOH
21. How do strong and weak acids differ?
    1. Strong acids dissociate completely in aqueous solution and weak acids don’t.
    2. Only strong acids produce hydronium in aqueous solution.
    3. Strong acids donate protons and weak acids do not.
    4. Strong acids increase the concentration of ^–OH in solution.
    5. Weak acids degrade less readily than strong acids.
22. Which of the following strong acids is found in the body?
    1. HNO₃
    2. HCl
    3. H­₂SO₄
    4. HClO₄
    5. HBr
23. Which of the following acids is not a strong acid?
    1. HCl
    2. HI
    3. HNO₃
    4. CH₃COOH
    5. H₂SO₄
24. Which of the following bases is a strong base?
    1. LiOH
    2. 
    3. NH₂CH₂COOH
    4. NH₂CH₂CH₂CH₂NH₂
    5. All of the above molecules are strong bases.
25. Generally, strong bases are hydroxide salts of
    1. transition metals.
    2. the halogens.
    3. alkali and alkaline earth metals.
    4. the noble gases.
    5. any element.
26. Each circle is a sample of an aqueous acidic or basic solution. Which of the solutions contains a weak base?

a. b. c. d. e.

1. Each circle is a sample of an aqueous acidic or basic solution. Which of the solutions contains a weak acid?

a. b. c. d. e.

1. Each circle is a sample of an aqueous acidic or basic solution. Which of the solutions contains a strong base?

a. b. c. d. e.

1. Each circle is a sample of an aqueous acidic or basic solution. Which of the solutions contains a strong acid?

a. b. c. d. e.

1. Which of the statements describes the following reaction?

Mg(OH)₂ → Mg²⁺ + 2 HO⁻

• 1. This reaction is the dissociation of a strong acid.
  2. This reaction is the dissociation of a weak acid.
  3. This is the reaction of a strong base.
  4. This is the reaction of a weak base.
  5. This is not an acid-base reaction.

1. Which of the statements best describes the following reaction?

HCOOH + H₂O HCOO⁻ + H₃O⁺

• 1. This reaction is the dissociation of a strong acid.
  2. This reaction is the dissociation of a weak acid.
  3. This is the reaction of a strong base.
  4. This is the reaction of a weak base.
  5. This is not an acid-base reaction.

1. Which of the statements best describes the following reaction?

• 1. This reaction is the dissociation of a strong acid.
  2. This reaction is the dissociation of a weak acid.
  3. This is the reaction of a strong base.
  4. This is the reaction of a weak base.
  5. This is not an acid-base reaction.

1. Which of the following acidic functional groups is often involved in biochemical reactions in the body?
   1. HO⁻
   2. H₂SO₄
   3. RCOOH
   4. H₃O⁺
   5. ROR
2. A weak acid is also a _________ because it produces a low concentration of ions in solution.
   1. weak electrolyte
   2. strong electrolyte
   3. nonelectrolyte
   4. weak base
   5. strong acid
3. Which of the following is NOT a common use of a base?
   1. Many fruits get their sour or tart taste from bases.
   2. Amino acids contain bases.
   3. Many pharmaceuticals are bases.
   4. Cleaning agents are often bases.
   5. Neurotransmitters are bases.
4. The following reaction is a reversible reaction. Which of the following statements best describes what it means for this reaction to be reversible?

HCOOH + H₂O HCOO⁻ + H₃O⁺

• 1. This reaction only occurs in the reverse direction as written above.
  2. All of the reactant molecules react to make product and then all of the product molecules react to make reactants again.
  3. Forward and reverse reactions proceed at the same rate.
  4. Forward and reverse reactions occur simultaneously.
  5. The rate of the reverse reaction is must faster than the rate of the forward reaction.

1. Which of the following statements best describes what it means for the acid-base reaction between acetic acid and water to be in equilibrium?

CH₃COOH + H₂O CH₃COO⁻ + H₃O⁺

• 1. The mass of acetic acid and acetate is equal.
  2. The number of moles of acetate equals the number of moles of acetic acid.
  3. The number of moles of hydronium equals the number of moles of water.
  4. The forward and reverse reactions proceed at the same rate.
  5. The reaction is balanced.

1. In the acid-base reaction between ammonia and water, which of the following substances are present at equilibrium?

NH₃ + H₂O ⁺NH₄ + ⁻OH

ammonia water ammonium hydroxide

• 1. Ammonia, water, ammonium, and hydroxide are all present at equilibrium.
  2. Only ammonia and water are present at equilibrium.
  3. Only ammonium and hydroxide are present at equilibrium.
  4. Only hydroxide and hydronium are present at equilibrium.
  5. It is not possible to say which molecules will be present at equilibrium.

1. In the acid-base reaction between ammonia and water, which of the following statements best describes the concentration of ammonia and ammonium at equilibrium?

NH₃ + H₂O ⁺NH₄ + ⁻OH

ammonia water ammonium hydroxide

• 1. The concentration of ammonium is increasing.
  2. There is no ammonium at equilibrium.
  3. Their concentrations are equal.
  4. Their concentrations are constant.
  5. There is no ammonia at equilibrium.

1. In the acid-base reaction between ammonia and water, which bond is broken in order to give ammonium and hydroxide?

NH₃ + H₂O ⁺NH₄ + ⁻OH

ammonia water ammonium hydroxide

• 1. H-H
  2. N-O
  3. N-H
  4. O-H
  5. All of the above

1. In the acid-base reaction between ammonia and water, which bond is made in order to make ammonia and water from ammonium and hydroxide?

NH₃ + H₂O ⁺NH₄ + ⁻OH

ammonia water ammonium hydroxide

• 1. H-H
  2. N-O
  3. N-H
  4. O-H
  5. All of the above

1. Which substance is acting as the acid in the reverse reaction of the acid-base reaction below?

NH₃ + H₂O ⁺NH₄ + ⁻OH

ammonia water ammonium hydroxide

• 1. ammonia
  2. water
  3. ammonium
  4. hydroxide
  5. hydronium

1. What does K_a measure?
   1. the concentration of water at equilibrium
   2. the concentration of products divided by reactants at equilibrium
   3. the concentration of hydronium at equilibrium
   4. the concentration of hydroxide at equilibrium
   5. K_a is not a measurement
2. The pK_a of aspirin is 3.5. What is the K_a of aspirin?
   1. 3.5
   2. 1000
   3. 0.54
   4. 3.2 × 10^-4
   5. 3.2 × 10³
3. Methylamide (CH₃CONH₂) has a K_a of 1 × 10^-16. What is the pK_a of methylamide?
   1. −16
   2. 0
   3. 16
   4. 1 × 10^-16
   5. −1 × 10^-16
4. Acetic acid (CH₃COOH) has a pK_a of 4.74, while ethanol (CH₃CH₂OH) has a pK_a of about 16. Which molecule is more acidic?
   1. acetic acid, because it has a higher pK_a
   2. acetic acid, because it has a lower pK_a
   3. ethanol, because it has a higher pK_a
   4. ethanol, because it has a lower pK_a
   5. They have the same acidity.
5. An alkene has a pK_a of 40, while an alkyne has a pK_a of 25. Which functional group is more acidic?
   1. an alkyne, because it has a higher pK_a
   2. an alkyne, because it has a lower pK_a
   3. an alkene, because it has a higher pK_a
   4. an alkene, because it has a lower pK_a
   5. They have the same acidity.
6. The reaction between acetic acid and water is given below, followed by a list of changes that could be made to the reaction solution. Which of these changes will result in the equilibrium shifting to the left?

CH₃COOH + H₂O CH₃COO⁻ + H₃O⁺

Changes that could be made to the solution

• 1. adding more CH₃COOH
  2. removing H₂O
  3. removing H₃O⁺
  4. adding more CH₃COO⁻

1. All of these changes will result in the equilibrium shifting to the left.
2. Only I will result in the equilibrium shifting to the left.
3. Only IV will result in the equilibrium shifting to the left.
4. I and III will result in the equilibrium shifting to the left.
5. II and IV will result in the equilibrium shifting to the left.
6. Ammonia and ammonium are both present in water at equilibrium, as shown by the following acid-base equation. What will happen if ammonium is added to a solution of ammonia and ammonium at equilibrium?

NH₃ + H₂O ⁺NH₄ + ⁻OH

ammonia water ammonium hydroxide

• 1. Nothing.
  2. The result is not predictable.
  3. The ammonium will bubble.
  4. The equilibrium will shift to the right.
  5. The equilibrium will shift to the left.

1. Arsenic poisoning is a serious problem in many parts of the world. When arsenic poisoning occurs, arsenic binds to proteins and eventually causes cellular damage. This leads to a variety of symptoms in humans including exhaustion, muscle weakness, organ failure, and cancer. Arsenic poisoning is commonly treated with a drug called dimercaprol (or BAL) that binds arsenic, which sets up a competing equilibrium within the body. Once arsenic reacts to form a complex with BAL, it can be excreted from the body.

Arsenic-protein complex Arsenic + proteins + BAL Arsenic-BAL complex

How does treatment with BAL affect the equilibrium shown above?

• 1. Adding BAL does not affect the equilibrium.
  2. Adding BAL pushes the reaction to the left.
  3. Adding BAL pushes the reaction to the right.
  4. Adding BAL causes less arsenic-BAL to be made.
  5. Adding BAL causes more arsenic-protein complex to be made.

1. Which of the following statements does NOT correctly describe pH?
   1. pH is a measure of acidity of a solution.
   2. pH is a measure of hydronium concentration in a solution.
   3. The higher the pH, the more acidic a solution.
   4. A pH of 7 is a neutral solution.
   5. pH = −log [H₃O⁺].
2. According to the following table, what is the most acidic fluid in the body?

• 1. gastric juice
  2. sweat
  3. urine
  4. saliva
  5. blood

1. What is the concentration of H₃O⁺ and ^–OH in pure water at room temperature?
   1. 1.0 × 10⁻¹⁴ M
   2. 1.0 × 10⁻⁷ M
   3. 1.0 M
   4. 1.0 × 10⁷ M
   5. 1.0 × 10¹⁴ M
2. Adding an acid to pure water will change which of the following values: [H₃O⁺], [HO⁻], and/or K_w?
   1. [H₃O⁺] only
   2. [HO⁻] only
   3. K_w only
   4. [H₃O⁺] and [HO⁻], but not K_w
   5. All of these values will be changed.

1. The concentration of H₃O⁺ in a solution is 1 × 10⁻⁴ M. Which of the following statements describes how the concentration of ^–OH in the solution could be determined?
   1. It is not possible to determine [⁻OH].
   2. Calculate pH
   3. Measure the pH with a pH probe or dipstick
   4. Solve for [⁻OH] using the ion-product constant equation
   5. The [⁻OH] is unchanged when an acid is added to a solution.
2. What is the [OH⁻] in a solution that has a [H₃O⁺] of 1 × 10⁻⁶ M?
   1. 1 × 10⁻²⁰ M
   2. 1 × 10⁻⁸ M
   3. 1 × 10⁻⁶ M
   4. 1 × 10⁻⁷ M
   5. 1 × 10⁷ M
3. What is the [H₃O⁺] in a solution that has a [OH⁻] of 3.2 × 10⁻⁴ M?
   1. 3.2 × 10⁻¹⁰ M
   2. 3.2 × 10¹⁰ M
   3. 3.1 × 10⁻¹¹ M
   4. 3.1 × 10¹¹ M
   5. 1.0 × 10⁻⁷ M
4. Which of the following solutions has the highest concentration of [⁻OH]?
   1. a solution with a [H₃O⁺] of 1 × 10⁻⁵ M
   2. a solution with a [H₃O⁺] of 1 × 10⁻¹³ M
   3. a solution with a [HO⁻] of 1 × 10⁻⁵ M
   4. a solution with a [HO⁻] of 1 × 10⁻¹³ M
   5. a solution with a [HO⁻] of 1 × 10⁻² M
5. Which of the following solutions has the highest concentration of [⁻OH]?
   1. a solution with a pH of 4
   2. a solution with a pH of 10
   3. a solution with a [H₃O⁺] of 6.8 × 10⁻⁵ M
   4. a solution with a [H₃O⁺] of 1 × 10⁻¹³ M
   5. a solution with a [HO⁻] of 1 × 10⁻² M
6. What is the pH of a solution with a [H₃O⁺] of 1.0 × 10⁻⁵ M?
   1. 9.00
   2. 1.0 × 10⁻⁵ M
   3. −5.00
   4. −9.00
   5. 5.00
7. What is the pH of a solution with a [⁻OH ] of 1.0 × 10⁻¹⁰ M?
   1. 1.0 × 10⁻¹⁰
   2. 10.0
   3. 4.00
   4. −10.0
   5. −4.00
8. What is the pH of a solution with a [H₃O⁺] of 7.9 × 10⁻¹¹ M?
   1. 10.1
   2. −10.1
   3. 3.90
   4. −3.90
   5. 11.9
9. What is the pH of a solution with a [⁻OH ] of 4.1 × 10⁻³ M?
   1. −2.39
   2. 2.39
   3. 11.6
   4. −11.6
   5. 7.00
10. A blood sample has a pH of 7.42. What is the concentration of hydronium in the sample?
    1. 0.87 M
    2. 2.6 × 10⁷ M
    3. −2.6 × 10⁷ M
    4. 3.8 × 10⁸ M
    5. 3.8 × 10⁻⁸ M
11. A sample of gastric juice has a pH of 1.20. What is the concentration of hydroxide in this sample?
    1. 1.6 × 10⁻¹³ M
    2. 6.3 × 10⁻² M
    3. 1.0 × 10⁻⁷ M
    4. 6.3 × 10¹² M
    5. 6.3 × 10⁻¹⁶ M
12. What is the pH of a urine sample with a hydronium concentration of 7.9 × 10⁻⁸?
    1. −7.10
    2. 7.10
    3. 6.90
    4. −6.90
    5. 7.00
13. Which statement does NOT correctly explain why it is so important for intracellular pH to be maintained between 7.35 and 7.45?
    1. In this range, carboxylic acids, phosphate esters, and amines are ionized.
    2. In this range, the molecules are trapped within the cell.
    3. In this range, the concentration of biomolecules is high enough for key reactions to take place.
    4. In this range, molecules in biochemical pathways can bind to enzymes appropriately.
    5. In this range, molecules in biochemical pathways are inert.
14. Which of the following pH ranges is referred to as physiological pH?
    1. pH 6 – pH 8
    2. pH 7.35 – pH 7.45
    3. pH 6.7 – pH 6.8
    4. pH 6.5 – pH 7.5
    5. pH 5 – pH 8
15. At physiological pH, phosphate esters, such as the molecule of methyl phosphate shown below, are ionized. Which of the following choices is the ionized form of a phosphate ester?

methyl phosphate

a. b. c. d. e.

1. The [H₃O⁺] of a solution with a pH of 2 is ______ the [H₃O⁺] of a solution with a pH of 3.
   1. one-tenth
   2. ten times
   3. one-half
   4. twice
   5. the same as
2. Gastric juice is the most acidic fluid in the body. Why is gastric juice so acidic?
   1. to convert inactive proteins to active ones
   2. to kill bacteria
   3. to denature proteins
   4. to break down food
   5. All of the above
3. According to the chart below, how are protons be excreted from the body?

• 1. by sweating
  2. by urinating and through sweating
  3. by urinating only
  4. by throwing up
  5. by urinating, sweating, or throwing up

1. Metabolic acidosis is a type of acid-base imbalance that results in a low blood pH. It can lead to a range of symptoms including headaches, confusion, lethargy, and even death due to heart failure when the blood pH drops below 7.0. In which of the following circumstances would you suspect metabolic acidosis?

• 1. a bulimic patient who throws up several times a day
  2. a bulimic patient who abuses diuretics to urinate frequently
  3. a patient who is unable to urinate
  4. a patient complaining of excess sweating
  5. All of the above

1. Which of the following statements best describe a neutralization reaction?
   1. An acid and base react to give a salt and sometimes water.
   2. Two aqueous molecules react to give a liquid.
   3. A positively charged ion reacts to give a neutral molecule.
   4. An anion and a cation react to give a neutral molecule.
   5. Two neutral molecules react to give a cation and an anion.
2. Which statement about neutralization reactions is FALSE?
   1. Neutralization reactions occur between an acid and a base.
   2. Neutralization reactions are equilibrium reactions.
   3. Neutralization reactions produce water.
   4. Neutralization reactions sometimes produce carbon dioxide.
   5. Neutralization reactions always go to completion.
3. Which of the following is a balanced equation for a neutralization reaction?
   1. Al(OH)₃(s) + HCl → 3 H₂O + AlCl₃(aq)
   2. Mg(OH)₂(s) + HNO₃ → 2 H₂O + Mg(NO₃)₂(aq)
   3. Ca(OH)₂(s) + HNO₃ → 2 H₂O + Ca(NO₃)₂(aq)
   4. KOH(s) + HNO₃ → H₂O + KNO₃(aq)
   5. 2 Al(OH)₃(s) + HCl → 3 H₂O + AlCl₃(aq)
4. Which species in the following neutralization reaction are spectator ions?

NaOH + HCl → H₂O + NaCl

• 1. H₃O⁺
  2. ^–OH
  3. H₂O
  4. NaCl
  5. H⁺

1. The neutralization reaction of potassium hydrogen carbonate (KHCO₃) and HI produces what spectator ion?
   1. CO₂
   2. KI
   3. H₂CO₃
   4. H₂O
   5. H⁺
2. The neutralization reaction of potassium hydrogen carbonate (KHCO₃) and HI produces what gas?
   1. CO₂
   2. O₂
   3. H₂CO₃
   4. H₂O
   5. H⁺
3. Lidocaine, a common injectable dental anesthetic, is available as a 1% lidocaine-HCl solution, as shown on the following drug label. What is the purpose of HCl in the injection solution?

1% Lidocaine

HCl Inj., USP

50 mg (10 mg/mL)

5 mL

xxxxx laboratories

xxxxx, xx, xxxxxx USA

• 1. It makes lidocaine easier to store.
  2. It makes lidocaine more reactive.
  3. It makes lidocaine more soluble.
  4. It is the active ingredient of the medicine.
  5. It is a preservative.

1. Lidocaine, a common injectable dental anesthetic, is available as a 1% lidocaine-HCl solution, as shown on the following drug label. Lidocaine-HCl is a(n)

1% Lidocaine

HCl Inj., USP

50 mg (10 mg/mL)

5 mL

xxxxx laboratories

xxxxx, xx, xxxxxx USA

1. weak acid.
2. base.
3. salt.
4. strong acid.
5. unstable molecule.
6. Lidocaine, a common injectable dental anesthetic, is available as a 1% lidocaine-HCl solution. The last step in the manufacture of lidocaine is a neutralization reaction. Which of the following reactions is the neutralization of lidocaine?

1. Which of the following statements does NOT describe a pH buffer?
   1. A common buffer is a solution of acetic acid and acetate.
   2. A buffer is a weak acid and the acid’s conjugate base in equal concentrations.
   3. A buffer is a physical barrier that blocks the addition of acid or base to a solution.
   4. A buffer is a solution that resists change of pH upon addition of small amounts of acid or base.
   5. Phosphates, bicarbonate, and proteins are all buffering systems in the body.
2. Which of the following is a buffer system?
   1. H₂CO₃ and HCO₃⁻
   2. NaCl and NaOH
   3. HCl and NaOH
   4. H₂O and HCl
   5. NaCl and NaNO₃
3. A buffer solution contains H₂CO₃ and HCO₃⁻, resulting in the equilibrium shown by the reaction below. According to this reaction and LeChatelier’s principle, what happens when acid (H₃O⁺) is added to this buffer solution?

• 1. More HCO₃⁻ is formed.
  2. More H₃O⁺ is formed.
  3. More H₂CO₃ is formed
  4. Less H₂O is formed.
  5. The reaction shifts to the right.

1. Consider a buffer solution containing CH₃COO⁻Na⁺ and CH₃COOH. If you add hydronium (H₃O⁺) until all of the CH₃COO⁻ is converted into CH₃COOH and then add a little more hydronium, what do you expect to observe?
   1. The pH increases.
   2. The pH decreases.
   3. The pH stays the same.
   4. The solution will be neutralized.
   5. The pH changes, but it is not possible to determine how it will change.
2. The following figure illustrates the action of a HF and F⁻ buffer where the sizes of the boxes are proportional to the concentrations of HF and F⁻ in solution. According to this figure, what happens when H₃O⁺ is added to the HF/F⁻ buffer?

HF F^-

HF F⁻

HF F⁻

Add

H₃O⁺

Add

HO⁻

• 1. The pH decreases.
  2. The pH increases.
  3. The concentration of HF increases.
  4. The concentration of F⁻ increases.
  5. Nothing happens.

1. The following figure illustrates the action of a HF and F⁻ buffer where the sizes of the boxes are proportional to the concentrations of HF and F⁻ in solution. What will happen when a small amount of base (⁻OH) is added to the HF/F⁻ buffer?

HF F^-

HF F⁻

HF F⁻

Add

H₃O⁺

Add

HO⁻

• 1. The concentration of ^–OH will increase.
  2. The concentration of H₃O⁺ will increase.
  3. The concentration of HF will increase.
  4. The concentration of F⁻ will increase.
  5. The pH of the solution will increase.

1. The following figure illustrates the action of a HF and F⁻ buffer where the sizes of the boxes are proportional to the concentrations of HF and F⁻ in solution. Which of the following chemical equations represents the reaction that occurs when ^–OH is added to the HF/F⁻ buffer?

HF F^-

HF F⁻

HF F⁻

Add

H₃O⁺

Add

HO⁻

• 1. HF + H₂O F⁻ + H₃O⁺
  2. F⁻ + H₂O F⁻ + ⁻OH
  3. HF + ⁻OH F⁻ + H₂O
  4. F⁻ + 2 ⁻OH HF + O₂
  5. F⁻ + ⁻OH HOF

1. The following figure illustrates the action of a HF and F⁻ buffer where the sizes of the boxes are proportional to the concentrations of HF and F⁻ in solution. If you add hydronium until all of the F⁻ is converted into HF and then add a little more hydronium, what is observed?

HF F^-

HF F⁻

HF F⁻

Add

H₃O⁺

Add

HO⁻

• 1. The pH increases.
  2. The pH decreases.
  3. The pH stays the same.
  4. The solution will be neutralized.
  5. The pH changes, but it is not possible to determine how it will change.

1. Which of the following statements does NOT correctly describe buffer capacity?
   1. Buffer capacity is determined only by the identity of the buffer.
   2. The addition of amounts of acid or base exceeding the buffer capacity will change the pH of the solution.
   3. The higher the concentration of weak acid and conjugate base in solution, the higher the buffer capacity.
   4. The greatest amount of acid or base that a buffer can accept while maintaining pH is called the buffer capacity.
   5. Once the buffer capacity is exceeded in cells, key functions of the body can be disrupted.
2. What happens to pH when the buffer capacity of a solution is exceeded?
   1. The pH increases.
   2. The pH decreases.
   3. The solution will become unstable.
   4. The pH will either increase or decrease, depending on whether acid or base is added to the solution.
   5. The pH will not be changed.
3. Which of the following buffer systems is the primary buffering system in the blood?
   1. Proteins
   2. DNA and RNA
   3. H₂PO₄⁻/HPO₄²⁻
   4. H₂CO₃/HCO₃⁻
   5. CH₃COOH/CH₃COO⁻
4. The buffering system of the blood is shown below. Which of the following equations represents the reaction that occurs when hydroxide is added to this buffer?

CO₂ + H₂O H₂CO₃ + H₂O HCO₃^- + H₃O⁺

• 1. CO₂ + ⁻OH → CO₃²⁻ + H⁺
  2. H₂CO₃ + ⁻OH → HCO₃⁻ + H₂O
  3. HCO₃⁻ + ⁻OH → CO₃²⁻ + H₂O
  4. HCO₃⁻ + ⁻OH → CO₂ + H₂O₂
  5. H₃O⁺ + ⁻OH → 2 H₂O

1. When a person hyperventilates, they breathe very quickly, exhaling CO₂ more quickly than it can be produced. This reduces the concentration of CO₂ in the blood. According to the chemical equation below and LeChatelier’s principle, how is the bicarbonate equilibrium affected by the reduction of CO₂ in the blood?

CO₂ + H₂O H₂CO₃ + H₂O HCO₃^- + H₃O⁺

• 1. The equilibrium is unchanged.
  2. More H₃O⁺ is produced.
  3. The equilibrium is shifted to the right.
  4. The H₃O⁺ concentration decreases.
  5. More HCO₃⁻ is produced.

1. Which of the following changes in blood pH would you expect to observe in a hyperventilating patient, and what are those changes called?
   1. a drop in pH, alkalosis
   2. a drop in pH, acidosis
   3. an increase in pH, alkalosis
   4. an increase in pH, acidosis
   5. There will not be any change in blood pH.
2. Which of the following would be the best treatment of metabolic acidosis?
   1. the IV administration of an acid
   2. the IV administration of a weak base
   3. breathing into a paper bag
   4. the IV administration of HCl
   5. reducing breathing rate
3. Which of the following conditions could cause respiratory acidosis?
   1. hyperventilation
   2. asthma
   3. kidney failure
   4. excessive vomiting
   5. starvation
4. Which of the following statements best describes the purpose of insulin in the body?
   1. Insulin transports carbohydrates through the bloodstream.
   2. Insulin controls glucose concentration in the blood.
   3. Insulin breaks down sugars in the body.
   4. Insulin protects sugars from being broken down by enzymes.
   5. Insulin controls protein metabolism.
5. How do Type I and Type II diabetes differ?
   1. Type I only occurs in children, and Type II only occurs in adults.
   2. Type I is controllable by diet and exercise, and Type II is controlled only through insulin injection.
   3. Type I can lead to coma and death, and Type II does not have serious effects on the body.
   4. The pancreas does not produce sufficient insulin in Type I, and there is a lack of insulin receptors with Type II.
   5. All of the above
6. Where does digestion of proteins begin?
   1. in the mouth
   2. in the esophagus
   3. in the stomach
   4. in the small intestine
   5. in the large intestine
7. What is an enteric coating?
   1. It is the acidic coating of the small intestine that causes degradation of drugs.
   2. It is the basic coating of the small intestine that causes degradation of drugs.
   3. It is an coating that protects orally administered drugs from degradation in the stomach.
   4. It is a drug coating used to make medication more palatable.
   5. It is a coating that protects orally administered drugs from degradation in the small intestine.