CHEM134 Final Exam Practice Test Set
Exam Practice Questions And Correct
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1. A 5.00 g sample of calcium carbonate is heated until decomposition is
complete according to the reaction CaCO₃(s) → CaO(s) + CO₂(g). If 2.20
g of carbon dioxide is collected, what is the percent yield of CO₂?
A. 44.0%
B. 100.0%
C. 88.0%
D. 50.0%
Rationale: One mole of CaCO₃ produces one mole of CO₂. A 5.00 g sample
of CaCO₃ is approximately 0.0500 mol, producing a theoretical 2.20 g CO₂.
Since the actual yield equals the theoretical yield, the percent yield is
100.0%.
2. Which quantum number determines the orientation of an orbital in
space?
A. Principal quantum number (n)
B. Spin quantum number (ms)
, C. Magnetic quantum number (ml)
D. Angular momentum quantum number (l)
Rationale: The magnetic quantum number specifies the orientation of an
orbital within a subshell, while n determines energy level, l determines
orbital shape, and ms specifies electron spin.
3. Which element has the highest first ionization energy?
A. Sodium
B. Magnesium
C. Aluminum
D. Neon
Rationale: Noble gases possess filled valence shells and exhibit
exceptionally high ionization energies because removing an electron
disrupts a very stable configuration.
4. According to VSEPR theory, the molecular geometry of SF₄ is:
A. Tetrahedral
B. Trigonal bipyramidal
C. Seesaw
D. Square planar
Rationale: Sulfur tetrafluoride contains five electron domains with one
lone pair, producing a seesaw molecular geometry derived from a trigonal
bipyramidal electron arrangement.
5. Which intermolecular force is primarily responsible for the unusually
high boiling point of water?
A. London dispersion forces
B. Dipole-induced dipole forces
C. Ion-dipole forces
D. Hydrogen bonding
, Rationale: Strong hydrogen bonding between water molecules significantly
increases the energy required for vaporization, resulting in an unusually
high boiling point.
6. Which gas law states that pressure is inversely proportional to volume
at constant temperature?
A. Charles's law
B. Gay-Lussac's law
C. Avogadro's law
D. Boyle's law
Rationale: Boyle's law describes the inverse relationship between pressure
and volume when temperature and amount of gas remain constant.
7. The strongest electrolyte among the following is:
A. Glucose
B. Acetic acid
C. Ammonia
D. Sodium chloride
Rationale: Sodium chloride dissociates completely into ions in water,
making it a strong electrolyte, whereas the others are weak electrolytes or
nonelectrolytes.
8. If ΔH is negative and ΔS is positive, the reaction is:
A. Never spontaneous
B. Spontaneous only at high temperatures
C. Spontaneous only at low temperatures
D. Spontaneous at all temperatures
Rationale: A negative enthalpy change and positive entropy change make
ΔG negative regardless of temperature, ensuring spontaneity.
9. Which expression represents the equilibrium constant for the reaction
N₂(g) + 3H₂(g) ⇌ 2NH₃(g)?
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
1. A 5.00 g sample of calcium carbonate is heated until decomposition is
complete according to the reaction CaCO₃(s) → CaO(s) + CO₂(g). If 2.20
g of carbon dioxide is collected, what is the percent yield of CO₂?
A. 44.0%
B. 100.0%
C. 88.0%
D. 50.0%
Rationale: One mole of CaCO₃ produces one mole of CO₂. A 5.00 g sample
of CaCO₃ is approximately 0.0500 mol, producing a theoretical 2.20 g CO₂.
Since the actual yield equals the theoretical yield, the percent yield is
100.0%.
2. Which quantum number determines the orientation of an orbital in
space?
A. Principal quantum number (n)
B. Spin quantum number (ms)
, C. Magnetic quantum number (ml)
D. Angular momentum quantum number (l)
Rationale: The magnetic quantum number specifies the orientation of an
orbital within a subshell, while n determines energy level, l determines
orbital shape, and ms specifies electron spin.
3. Which element has the highest first ionization energy?
A. Sodium
B. Magnesium
C. Aluminum
D. Neon
Rationale: Noble gases possess filled valence shells and exhibit
exceptionally high ionization energies because removing an electron
disrupts a very stable configuration.
4. According to VSEPR theory, the molecular geometry of SF₄ is:
A. Tetrahedral
B. Trigonal bipyramidal
C. Seesaw
D. Square planar
Rationale: Sulfur tetrafluoride contains five electron domains with one
lone pair, producing a seesaw molecular geometry derived from a trigonal
bipyramidal electron arrangement.
5. Which intermolecular force is primarily responsible for the unusually
high boiling point of water?
A. London dispersion forces
B. Dipole-induced dipole forces
C. Ion-dipole forces
D. Hydrogen bonding
, Rationale: Strong hydrogen bonding between water molecules significantly
increases the energy required for vaporization, resulting in an unusually
high boiling point.
6. Which gas law states that pressure is inversely proportional to volume
at constant temperature?
A. Charles's law
B. Gay-Lussac's law
C. Avogadro's law
D. Boyle's law
Rationale: Boyle's law describes the inverse relationship between pressure
and volume when temperature and amount of gas remain constant.
7. The strongest electrolyte among the following is:
A. Glucose
B. Acetic acid
C. Ammonia
D. Sodium chloride
Rationale: Sodium chloride dissociates completely into ions in water,
making it a strong electrolyte, whereas the others are weak electrolytes or
nonelectrolytes.
8. If ΔH is negative and ΔS is positive, the reaction is:
A. Never spontaneous
B. Spontaneous only at high temperatures
C. Spontaneous only at low temperatures
D. Spontaneous at all temperatures
Rationale: A negative enthalpy change and positive entropy change make
ΔG negative regardless of temperature, ensuring spontaneity.
9. Which expression represents the equilibrium constant for the reaction
N₂(g) + 3H₂(g) ⇌ 2NH₃(g)?
