CHEM 120 EXAM 2 2026/2027 | Chapters 5-8 | Chamberlain
College of Nursing | Verified Solutions | Pass Guaranteed -
A+ Graded
SECTION 1: Chapter 5 - Chemical Reactions & Equations (Q1-Q20)
Q1: What are the products of a complete combustion reaction of a hydrocarbon?
A. Carbon dioxide and water [CORRECT]
B. Carbon monoxide and water
C. Carbon and hydrogen gas
D. Carbonic acid and oxygen
Correct Answer: A
Rationale: Complete combustion of hydrocarbons always yields carbon dioxide and
water. Incomplete combustion produces carbon monoxide (B). Choice C describes
pyrolysis, and choice D describes dissolution of CO₂ in water, not combustion.
Q2: When magnesium metal burns in air, it forms magnesium oxide. What type of
reaction is this and what is oxidized?
A. Decomposition; magnesium is oxidized
B. Synthesis; oxygen is oxidized
C. Synthesis; magnesium is oxidized [CORRECT]
D. Combustion; oxygen is reduced
Correct Answer: C
Rationale: Two elements combine to form a compound, which is a synthesis reaction.
Magnesium changes from oxidation state 0 to +2, losing electrons (oxidation). Oxygen
is reduced from 0 to –2. Choice A misidentifies the reaction type, and choice B
incorrectly states oxygen is oxidized.
Q3: Which is the net ionic equation for the reaction between aqueous silver nitrate and
aqueous sodium chloride?
A. Ag⁺(aq) + Cl⁻(aq) → AgCl(s) [CORRECT]
B. AgNO₃(aq) + NaCl(aq) → AgCl(s) + NaNO₃(aq)
C. Na⁺(aq) + NO₃⁻(aq) → NaNO₃(s)
,D. Ag⁺(aq) + NO₃⁻(aq) + Na⁺(aq) + Cl⁻(aq) → AgCl(s) + NaNO₃(aq)
Correct Answer: A
Rationale: The complete ionic equation shows all dissolved ions; spectator ions Na⁺ and
NO₃⁻ are eliminated, leaving only Ag⁺ and Cl⁻ forming the insoluble precipitate AgCl.
Choice B is the molecular equation, choice C incorrectly suggests NaNO₃ precipitates,
and choice D fails to eliminate spectators.
Q4: In the activity series of metals, which metal is typically the most reactive?
A. Gold
B. Silver
C. Copper
D. Potassium [CORRECT]
Correct Answer: D
Rationale: Potassium is near the top of the activity series and is highly reactive, readily
displacing hydrogen from water and acids. Gold, silver, and copper are near the bottom
and are relatively unreactive.
Q5: According to solubility rules, which compound is insoluble in water?
A. NaNO₃
B. K₂SO₄
C. AgCl [CORRECT]
D. NH₄Cl
Correct Answer: C
Rationale: Most chloride salts are soluble, but AgCl is a key exception and forms a
precipitate. All nitrates (A), most sulfates including K₂SO₄ (B), and all ammonium salts
(D) are soluble.
Q6: When aqueous solutions of Pb(NO₃)₂ and KI are mixed, a yellow precipitate forms.
What is the precipitate and why does it form?
A. KNO₃; it is insoluble
B. PbI₂; it is insoluble [CORRECT]
C. PbI₂; it is soluble
D. KNO₃; lead displaces potassium
Correct Answer: B
, Rationale: According to solubility rules, most iodides are soluble but PbI₂ is an exception
and precipitates. KNO₃ is soluble. Choice A identifies the wrong compound, choice C
has the correct compound but wrong solubility, and choice D misapplies the activity
series.
Q7: In the reaction 2Al + 3CuSO₄ → Al₂(SO₄)₃ + 3Cu, which species is oxidized?
A. Cu²⁺
B. SO₄²⁻
C. Al [CORRECT]
D. Cu
Correct Answer: C
Rationale: Aluminum changes from oxidation state 0 to +3, losing electrons (oxidation).
Cu²⁺ is reduced to Cu (0). SO₄²⁻ is a spectator ion, and choice D represents the reduced
species.
Q8: What is the net ionic equation for the reaction between aqueous barium chloride
and aqueous sodium sulfate?
A. Ba²⁺(aq) + SO₄²⁻(aq) → BaSO₄(s) [CORRECT]
B. BaCl₂(aq) + Na₂SO₄(aq) → BaSO₄(s) + 2NaCl(aq)
C. 2Na⁺(aq) + 2Cl⁻(aq) → 2NaCl(s)
D. Ba²⁺(aq) + 2Cl⁻(aq) + 2Na⁺(aq) + SO₄²⁻(aq) → BaSO₄(s) + 2NaCl(aq)
Correct Answer: A
Rationale: BaSO₄ is insoluble while NaCl remains dissolved; eliminating spectator ions
Na⁺ and Cl⁻ yields the net ionic equation. Choice B is the molecular equation, choice C
incorrectly suggests NaCl precipitates, and choice D fails to remove spectators.
Q9: Which equation represents a combustion reaction?
A. 2H₂ + O₂ → 2H₂O [CORRECT]
B. CaCO₃ → CaO + CO₂
C. Zn + 2HCl → ZnCl₂ + H₂
D. AgNO₃ + NaCl → AgCl + NaNO₃
Correct Answer: A
Rationale: Combustion involves a substance reacting rapidly with oxygen to produce
oxides and release energy; hydrogen combusts to form water. Choice B is
decomposition, choice C is single replacement, and choice D is double replacement.
College of Nursing | Verified Solutions | Pass Guaranteed -
A+ Graded
SECTION 1: Chapter 5 - Chemical Reactions & Equations (Q1-Q20)
Q1: What are the products of a complete combustion reaction of a hydrocarbon?
A. Carbon dioxide and water [CORRECT]
B. Carbon monoxide and water
C. Carbon and hydrogen gas
D. Carbonic acid and oxygen
Correct Answer: A
Rationale: Complete combustion of hydrocarbons always yields carbon dioxide and
water. Incomplete combustion produces carbon monoxide (B). Choice C describes
pyrolysis, and choice D describes dissolution of CO₂ in water, not combustion.
Q2: When magnesium metal burns in air, it forms magnesium oxide. What type of
reaction is this and what is oxidized?
A. Decomposition; magnesium is oxidized
B. Synthesis; oxygen is oxidized
C. Synthesis; magnesium is oxidized [CORRECT]
D. Combustion; oxygen is reduced
Correct Answer: C
Rationale: Two elements combine to form a compound, which is a synthesis reaction.
Magnesium changes from oxidation state 0 to +2, losing electrons (oxidation). Oxygen
is reduced from 0 to –2. Choice A misidentifies the reaction type, and choice B
incorrectly states oxygen is oxidized.
Q3: Which is the net ionic equation for the reaction between aqueous silver nitrate and
aqueous sodium chloride?
A. Ag⁺(aq) + Cl⁻(aq) → AgCl(s) [CORRECT]
B. AgNO₃(aq) + NaCl(aq) → AgCl(s) + NaNO₃(aq)
C. Na⁺(aq) + NO₃⁻(aq) → NaNO₃(s)
,D. Ag⁺(aq) + NO₃⁻(aq) + Na⁺(aq) + Cl⁻(aq) → AgCl(s) + NaNO₃(aq)
Correct Answer: A
Rationale: The complete ionic equation shows all dissolved ions; spectator ions Na⁺ and
NO₃⁻ are eliminated, leaving only Ag⁺ and Cl⁻ forming the insoluble precipitate AgCl.
Choice B is the molecular equation, choice C incorrectly suggests NaNO₃ precipitates,
and choice D fails to eliminate spectators.
Q4: In the activity series of metals, which metal is typically the most reactive?
A. Gold
B. Silver
C. Copper
D. Potassium [CORRECT]
Correct Answer: D
Rationale: Potassium is near the top of the activity series and is highly reactive, readily
displacing hydrogen from water and acids. Gold, silver, and copper are near the bottom
and are relatively unreactive.
Q5: According to solubility rules, which compound is insoluble in water?
A. NaNO₃
B. K₂SO₄
C. AgCl [CORRECT]
D. NH₄Cl
Correct Answer: C
Rationale: Most chloride salts are soluble, but AgCl is a key exception and forms a
precipitate. All nitrates (A), most sulfates including K₂SO₄ (B), and all ammonium salts
(D) are soluble.
Q6: When aqueous solutions of Pb(NO₃)₂ and KI are mixed, a yellow precipitate forms.
What is the precipitate and why does it form?
A. KNO₃; it is insoluble
B. PbI₂; it is insoluble [CORRECT]
C. PbI₂; it is soluble
D. KNO₃; lead displaces potassium
Correct Answer: B
, Rationale: According to solubility rules, most iodides are soluble but PbI₂ is an exception
and precipitates. KNO₃ is soluble. Choice A identifies the wrong compound, choice C
has the correct compound but wrong solubility, and choice D misapplies the activity
series.
Q7: In the reaction 2Al + 3CuSO₄ → Al₂(SO₄)₃ + 3Cu, which species is oxidized?
A. Cu²⁺
B. SO₄²⁻
C. Al [CORRECT]
D. Cu
Correct Answer: C
Rationale: Aluminum changes from oxidation state 0 to +3, losing electrons (oxidation).
Cu²⁺ is reduced to Cu (0). SO₄²⁻ is a spectator ion, and choice D represents the reduced
species.
Q8: What is the net ionic equation for the reaction between aqueous barium chloride
and aqueous sodium sulfate?
A. Ba²⁺(aq) + SO₄²⁻(aq) → BaSO₄(s) [CORRECT]
B. BaCl₂(aq) + Na₂SO₄(aq) → BaSO₄(s) + 2NaCl(aq)
C. 2Na⁺(aq) + 2Cl⁻(aq) → 2NaCl(s)
D. Ba²⁺(aq) + 2Cl⁻(aq) + 2Na⁺(aq) + SO₄²⁻(aq) → BaSO₄(s) + 2NaCl(aq)
Correct Answer: A
Rationale: BaSO₄ is insoluble while NaCl remains dissolved; eliminating spectator ions
Na⁺ and Cl⁻ yields the net ionic equation. Choice B is the molecular equation, choice C
incorrectly suggests NaCl precipitates, and choice D fails to remove spectators.
Q9: Which equation represents a combustion reaction?
A. 2H₂ + O₂ → 2H₂O [CORRECT]
B. CaCO₃ → CaO + CO₂
C. Zn + 2HCl → ZnCl₂ + H₂
D. AgNO₃ + NaCl → AgCl + NaNO₃
Correct Answer: A
Rationale: Combustion involves a substance reacting rapidly with oxygen to produce
oxides and release energy; hydrogen combusts to form water. Choice B is
decomposition, choice C is single replacement, and choice D is double replacement.
