,Verified CHEM 103 Module 8 Exam-General
Chemistry I-Portage - (26/27) Actual (PDF)
1. According to the Arrhenius definition, an acid is a substance that:
A) Increases the concentration of OH⁻ ions in aqueous solution
B) Increases the concentration of H⁺ (or H₃O⁺) ions in aqueous solution
C) Decreases the concentration of H⁺ ions in aqueous solution
D) Donates a proton to another substance
Correct Answer: B) Increases the concentration of H⁺ (or H₃O⁺) ions in aqueous solution
Rationale: The Arrhenius definition states that an acid is a substance that increases the concentration
of H⁺ (or H₃O⁺) ions when dissolved in water. Option A describes an Arrhenius base. Option C is
incorrect. Option D describes the Brønsted-Lowry definition of an acid.
2. According to the Brønsted-Lowry definition, a base is a substance that:
A) Increases the concentration of H⁺ ions in solution
B) Decreases the concentration of OH⁻ ions in solution
C) Accepts a proton (H⁺)
D) Donates a proton (H⁺)
Correct Answer: C) Accepts a proton (H⁺)
Rationale: The Brønsted-Lowry definition defines a base as a proton acceptor. An acid is a proton
donor. This definition is broader than the Arrhenius definition because it does not require water as a
solvent. Options A and B describe acid behavior, and D describes an acid.
3. Which of the following is an Arrhenius acid?
A) NH₃
B) NaOH
C) HCl
D) CH₃OH
Correct Answer: C) HCl
,Rationale: HCl (hydrochloric acid) is an Arrhenius acid because it increases the concentration of H⁺
ions in aqueous solution. NH₃ (A) is an Arrhenius base, NaOH (B) is an Arrhenius base, and CH₃OH (D)
is neither an acid nor a base by the Arrhenius definition.
4. Which of the following is an Arrhenius base?
A) HCl
B) H₂SO₄
C) NaOH
D) CH₃COOH
Correct Answer: C) NaOH
Rationale: NaOH (sodium hydroxide) is an Arrhenius base because it increases the concentration of
OH⁻ ions in aqueous solution. HCl (A), H₂SO₄ (B), and CH₃COOH (D) are all Arrhenius acids.
5. In the reaction HCl + H₂O → H₃O⁺ + Cl⁻, the conjugate acid of water is:
A) HCl
B) H₃O⁺
C) Cl⁻
D) H₂O
Correct Answer: B) H₃O⁺
Rationale: Water (H₂O) accepts a proton from HCl to form H₃O⁺. Therefore, H₃O⁺ is the conjugate acid
of water. HCl (A) is the acid, Cl⁻ (C) is the conjugate base of HCl, and H₂O (D) is the base.
6. In the reaction HCl + H₂O → H₃O⁺ + Cl⁻, the conjugate base of HCl is:
A) HCl
B) H₃O⁺
C) Cl⁻
D) H₂O
Correct Answer: C) Cl⁻
Rationale: HCl donates a proton to become Cl⁻. Therefore, Cl⁻ is the conjugate base of HCl. HCl (A) is
the acid, H₃O⁺ (B) is the conjugate acid of water, and H₂O (D) is the base.
, 7. In the reaction NH₃ + H₂O ⇌ NH₄⁺ + OH⁻, the conjugate acid of NH₃ is:
A) NH₃
B) H₂O
C) NH₄⁺
D) OH⁻
Correct Answer: C) NH₄⁺
Rationale: NH₃ accepts a proton from water to form NH₄⁺. Therefore, NH₄⁺ is the conjugate acid of
NH₃. NH₃ (A) is the base, H₂O (B) is the acid, and OH⁻ (D) is the conjugate base of water.
8. In the reaction NH₃ + H₂O ⇌ NH₄⁺ + OH⁻, the conjugate base of H₂O is:
A) NH₃
B) H₂O
C) NH₄⁺
D) OH⁻
Correct Answer: D) OH⁻
Rationale: H₂O donates a proton to NH₃ to form OH⁻. Therefore, OH⁻ is the conjugate base of H₂O. NH₃
(A) is the base, NH₄⁺ (C) is the conjugate acid of NH₃, and H₂O (B) is the acid.
9. Which of the following is a strong acid?
A) CH₃COOH (acetic acid)
B) H₂CO₃ (carbonic acid)
C) HCl (hydrochloric acid)
D) NH₄⁺
Correct Answer: C) HCl (hydrochloric acid)
Rationale: HCl is a strong acid that completely ionizes in aqueous solution. CH₃COOH (A) and H₂CO₃ (B)
are weak acids, and NH₄⁺ (D) is the conjugate acid of a weak base.
10. Which of the following is a weak acid?
A) HCl
Chemistry I-Portage - (26/27) Actual (PDF)
1. According to the Arrhenius definition, an acid is a substance that:
A) Increases the concentration of OH⁻ ions in aqueous solution
B) Increases the concentration of H⁺ (or H₃O⁺) ions in aqueous solution
C) Decreases the concentration of H⁺ ions in aqueous solution
D) Donates a proton to another substance
Correct Answer: B) Increases the concentration of H⁺ (or H₃O⁺) ions in aqueous solution
Rationale: The Arrhenius definition states that an acid is a substance that increases the concentration
of H⁺ (or H₃O⁺) ions when dissolved in water. Option A describes an Arrhenius base. Option C is
incorrect. Option D describes the Brønsted-Lowry definition of an acid.
2. According to the Brønsted-Lowry definition, a base is a substance that:
A) Increases the concentration of H⁺ ions in solution
B) Decreases the concentration of OH⁻ ions in solution
C) Accepts a proton (H⁺)
D) Donates a proton (H⁺)
Correct Answer: C) Accepts a proton (H⁺)
Rationale: The Brønsted-Lowry definition defines a base as a proton acceptor. An acid is a proton
donor. This definition is broader than the Arrhenius definition because it does not require water as a
solvent. Options A and B describe acid behavior, and D describes an acid.
3. Which of the following is an Arrhenius acid?
A) NH₃
B) NaOH
C) HCl
D) CH₃OH
Correct Answer: C) HCl
,Rationale: HCl (hydrochloric acid) is an Arrhenius acid because it increases the concentration of H⁺
ions in aqueous solution. NH₃ (A) is an Arrhenius base, NaOH (B) is an Arrhenius base, and CH₃OH (D)
is neither an acid nor a base by the Arrhenius definition.
4. Which of the following is an Arrhenius base?
A) HCl
B) H₂SO₄
C) NaOH
D) CH₃COOH
Correct Answer: C) NaOH
Rationale: NaOH (sodium hydroxide) is an Arrhenius base because it increases the concentration of
OH⁻ ions in aqueous solution. HCl (A), H₂SO₄ (B), and CH₃COOH (D) are all Arrhenius acids.
5. In the reaction HCl + H₂O → H₃O⁺ + Cl⁻, the conjugate acid of water is:
A) HCl
B) H₃O⁺
C) Cl⁻
D) H₂O
Correct Answer: B) H₃O⁺
Rationale: Water (H₂O) accepts a proton from HCl to form H₃O⁺. Therefore, H₃O⁺ is the conjugate acid
of water. HCl (A) is the acid, Cl⁻ (C) is the conjugate base of HCl, and H₂O (D) is the base.
6. In the reaction HCl + H₂O → H₃O⁺ + Cl⁻, the conjugate base of HCl is:
A) HCl
B) H₃O⁺
C) Cl⁻
D) H₂O
Correct Answer: C) Cl⁻
Rationale: HCl donates a proton to become Cl⁻. Therefore, Cl⁻ is the conjugate base of HCl. HCl (A) is
the acid, H₃O⁺ (B) is the conjugate acid of water, and H₂O (D) is the base.
, 7. In the reaction NH₃ + H₂O ⇌ NH₄⁺ + OH⁻, the conjugate acid of NH₃ is:
A) NH₃
B) H₂O
C) NH₄⁺
D) OH⁻
Correct Answer: C) NH₄⁺
Rationale: NH₃ accepts a proton from water to form NH₄⁺. Therefore, NH₄⁺ is the conjugate acid of
NH₃. NH₃ (A) is the base, H₂O (B) is the acid, and OH⁻ (D) is the conjugate base of water.
8. In the reaction NH₃ + H₂O ⇌ NH₄⁺ + OH⁻, the conjugate base of H₂O is:
A) NH₃
B) H₂O
C) NH₄⁺
D) OH⁻
Correct Answer: D) OH⁻
Rationale: H₂O donates a proton to NH₃ to form OH⁻. Therefore, OH⁻ is the conjugate base of H₂O. NH₃
(A) is the base, NH₄⁺ (C) is the conjugate acid of NH₃, and H₂O (B) is the acid.
9. Which of the following is a strong acid?
A) CH₃COOH (acetic acid)
B) H₂CO₃ (carbonic acid)
C) HCl (hydrochloric acid)
D) NH₄⁺
Correct Answer: C) HCl (hydrochloric acid)
Rationale: HCl is a strong acid that completely ionizes in aqueous solution. CH₃COOH (A) and H₂CO₃ (B)
are weak acids, and NH₄⁺ (D) is the conjugate acid of a weak base.
10. Which of the following is a weak acid?
A) HCl
