UNE GENERAL CHEMISTRY II MIDTERM
(WEEKS 1–7) 2026 | Complete Study Guide |
Verified Practice Questions, Correct
Answers & Detailed Explanations | Graded
A+ Exam Prep
UNE GENERAL CHEMISTRY II MIDTERM (WEEKS 1–7) 2026
Complete Study Guide | Verified Practice Questions, Correct Answers &
Detailed Explanations
DOCUMENT OVERVIEW
• This comprehensive study guide contains 200 carefully curated multiple-choice
practice questions covering all major Chemistry II topics from weeks 1–7, with
detailed explanations to reinforce your understanding and build exam confidence.
• Study strategically by working through questions section by section, reviewing
rationales for both correct and incorrect answers to identify knowledge gaps and
master essential concepts before the midterm.
SECTION 1: THERMODYNAMICS & ENERGY
**1. Which of the following is an example of an exothermic process?
A) Melting of ice at room temperature
B) Evaporation of water
C) Combustion of methane in air
D) Dissolution of ammonium nitrate in water
E) Photosynthesis in plants
CORRECT ANSWER: C) Combustion of methane in air
Rationale: Combustion reactions release energy in the form of heat and light to the
surroundings, making them exothermic. Melting ice and evaporation are
endothermic processes that require energy input. Dissolution of ammonium nitrate
,is endothermic (temperature decreases). Photosynthesis requires light energy
input, making it endothermic.
**2. What is the SI unit for enthalpy?
A) Joules (J)
B) Calories (cal)
C) Kilojoules (kJ)
D) Electron volts (eV)
E) Watts (W)
CORRECT ANSWER: A) Joules (J)
Rationale: The SI unit for all forms of energy, including enthalpy, is the joule (J).
While kilojoules (kJ) are commonly used in chemistry, the fundamental SI unit is
joules. Calories are non-SI units, electron volts measure energy at atomic scale, and
watts measure power (energy per time), not energy itself.
**3. For a spontaneous process at standard conditions, which relationship
must be true?
A) ΔG = 0
B) ΔG > 0
C) ΔG < 0
D) ΔH = TΔS
E) ΔS = 0
CORRECT ANSWER: C) ΔG < 0
Rationale: A spontaneous process is characterized by a negative Gibbs free energy
change (ΔG < 0). When ΔG = 0, the system is at equilibrium. When ΔG > 0, the
,process is non-spontaneous. The relationship ΔG = ΔH - TΔS governs spontaneity,
not the options listed for D and E.
**4. Which of the following has the greatest entropy in the solid state?
A) Diamond (C)
B) Graphite (C)
C) Silicon dioxide (SiO₂)
D) Ice (H₂O)
E) Sodium chloride (NaCl)
CORRECT ANSWER: B) Graphite (C)
Rationale: Graphite has a layered crystalline structure with weaker van der Waals
forces between layers compared to diamond's extremely rigid tetrahedral
structure. This allows greater molecular motion and disorder in graphite, resulting
in higher entropy. Diamond has extremely low entropy due to its rigid, highly
ordered structure.
**5. What is the relationship between entropy and temperature?
A) Entropy decreases as temperature increases
B) Entropy increases as temperature increases
C) Entropy is independent of temperature
D) Entropy becomes negative at high temperatures
E) Entropy reaches a maximum at 298 K
CORRECT ANSWER: B) Entropy increases as temperature increases
Rationale: According to the second law of thermodynamics, entropy increases with
temperature as molecules have greater kinetic energy and random molecular
motion. This is reflected in the third law of thermodynamics, which states that the
, entropy of a perfect crystal at absolute zero is zero, and increases as temperature
rises.
**6. Which process has a negative entropy change (ΔS < 0)?
A) Dissolution of sugar in water
B) Vaporization of water
C) Freezing of water into ice
D) Sublimation of dry ice
E) Mixing of two ideal gases
CORRECT ANSWER: C) Freezing of water into ice
Rationale: Freezing is a phase transition from liquid to solid, resulting in a more
ordered state with decreased randomness and negative ΔS. Dissolution,
vaporization, sublimation, and gas mixing all increase disorder and entropy
(positive ΔS).
**7. At what temperature would the reaction ΔH = +50 kJ and ΔS = +0.2 kJ/K
become spontaneous?
A) Below 250 K
B) Above 250 K
C) Below 200 K
D) Never, because ΔH is positive
E) At exactly 250 K
CORRECT ANSWER: B) Above 250 K
Rationale: Using ΔG = ΔH - TΔS, for spontaneity (ΔG < 0): 50 - T(0.2) < 0, which gives T
> 250 K. At higher temperatures, the -TΔS term becomes more negative, eventually
outweighing the positive ΔH value, making the overall ΔG negative.
(WEEKS 1–7) 2026 | Complete Study Guide |
Verified Practice Questions, Correct
Answers & Detailed Explanations | Graded
A+ Exam Prep
UNE GENERAL CHEMISTRY II MIDTERM (WEEKS 1–7) 2026
Complete Study Guide | Verified Practice Questions, Correct Answers &
Detailed Explanations
DOCUMENT OVERVIEW
• This comprehensive study guide contains 200 carefully curated multiple-choice
practice questions covering all major Chemistry II topics from weeks 1–7, with
detailed explanations to reinforce your understanding and build exam confidence.
• Study strategically by working through questions section by section, reviewing
rationales for both correct and incorrect answers to identify knowledge gaps and
master essential concepts before the midterm.
SECTION 1: THERMODYNAMICS & ENERGY
**1. Which of the following is an example of an exothermic process?
A) Melting of ice at room temperature
B) Evaporation of water
C) Combustion of methane in air
D) Dissolution of ammonium nitrate in water
E) Photosynthesis in plants
CORRECT ANSWER: C) Combustion of methane in air
Rationale: Combustion reactions release energy in the form of heat and light to the
surroundings, making them exothermic. Melting ice and evaporation are
endothermic processes that require energy input. Dissolution of ammonium nitrate
,is endothermic (temperature decreases). Photosynthesis requires light energy
input, making it endothermic.
**2. What is the SI unit for enthalpy?
A) Joules (J)
B) Calories (cal)
C) Kilojoules (kJ)
D) Electron volts (eV)
E) Watts (W)
CORRECT ANSWER: A) Joules (J)
Rationale: The SI unit for all forms of energy, including enthalpy, is the joule (J).
While kilojoules (kJ) are commonly used in chemistry, the fundamental SI unit is
joules. Calories are non-SI units, electron volts measure energy at atomic scale, and
watts measure power (energy per time), not energy itself.
**3. For a spontaneous process at standard conditions, which relationship
must be true?
A) ΔG = 0
B) ΔG > 0
C) ΔG < 0
D) ΔH = TΔS
E) ΔS = 0
CORRECT ANSWER: C) ΔG < 0
Rationale: A spontaneous process is characterized by a negative Gibbs free energy
change (ΔG < 0). When ΔG = 0, the system is at equilibrium. When ΔG > 0, the
,process is non-spontaneous. The relationship ΔG = ΔH - TΔS governs spontaneity,
not the options listed for D and E.
**4. Which of the following has the greatest entropy in the solid state?
A) Diamond (C)
B) Graphite (C)
C) Silicon dioxide (SiO₂)
D) Ice (H₂O)
E) Sodium chloride (NaCl)
CORRECT ANSWER: B) Graphite (C)
Rationale: Graphite has a layered crystalline structure with weaker van der Waals
forces between layers compared to diamond's extremely rigid tetrahedral
structure. This allows greater molecular motion and disorder in graphite, resulting
in higher entropy. Diamond has extremely low entropy due to its rigid, highly
ordered structure.
**5. What is the relationship between entropy and temperature?
A) Entropy decreases as temperature increases
B) Entropy increases as temperature increases
C) Entropy is independent of temperature
D) Entropy becomes negative at high temperatures
E) Entropy reaches a maximum at 298 K
CORRECT ANSWER: B) Entropy increases as temperature increases
Rationale: According to the second law of thermodynamics, entropy increases with
temperature as molecules have greater kinetic energy and random molecular
motion. This is reflected in the third law of thermodynamics, which states that the
, entropy of a perfect crystal at absolute zero is zero, and increases as temperature
rises.
**6. Which process has a negative entropy change (ΔS < 0)?
A) Dissolution of sugar in water
B) Vaporization of water
C) Freezing of water into ice
D) Sublimation of dry ice
E) Mixing of two ideal gases
CORRECT ANSWER: C) Freezing of water into ice
Rationale: Freezing is a phase transition from liquid to solid, resulting in a more
ordered state with decreased randomness and negative ΔS. Dissolution,
vaporization, sublimation, and gas mixing all increase disorder and entropy
(positive ΔS).
**7. At what temperature would the reaction ΔH = +50 kJ and ΔS = +0.2 kJ/K
become spontaneous?
A) Below 250 K
B) Above 250 K
C) Below 200 K
D) Never, because ΔH is positive
E) At exactly 250 K
CORRECT ANSWER: B) Above 250 K
Rationale: Using ΔG = ΔH - TΔS, for spontaneity (ΔG < 0): 50 - T(0.2) < 0, which gives T
> 250 K. At higher temperatures, the -TΔS term becomes more negative, eventually
outweighing the positive ΔH value, making the overall ΔG negative.
