UNE GENERAL CHEMISTRY II MIDTERM 2026
| Complete Study Guide | Verified Practice
Questions, Correct Answers & Detailed
Explanations | Latest Exam Prep PDF
UNE GENERAL CHEMISTRY II MIDTERM 2026 | Complete Study Guide
• 200 verified practice questions with detailed explanations to reinforce mastery
of General Chemistry II concepts
• Study guide format with correct answers highlighted and rationales provided for
every question to support active learning and concept retention
1. Which of the following is defined as the heat absorbed or released at
constant pressure?
A) Enthalpy
B) Entropy
C) Gibbs free energy
D) Internal energy
E) Heat capacity
✓ A) Enthalpy
Rationale: Enthalpy (H) is specifically defined as the heat content of a system at
constant pressure. It is the state function that measures the total heat absorbed or
released during a chemical reaction at constant pressure, making it the most
relevant thermodynamic function for understanding reactions in open systems and
at atmospheric conditions.
2. What is the sign of ΔH for an endothermic reaction?
A) Positive
B) Negative
C) Zero
,D) Undefined
E) Variable depending on temperature
✓ A) Positive
Rationale: Endothermic reactions absorb heat from the surroundings, meaning
energy is added to the system. This results in a positive ΔH value. The opposite is
true for exothermic reactions, which release heat and have negative ΔH values.
3. According to Hess's Law, the enthalpy change of a reaction depends on:
A) The path taken from reactants to products
B) The nature of the chemical bonds broken and formed
C) Only the initial and final states
D) Both B and C
E) The temperature and pressure of the reaction
✓ D) Both B and C
Rationale: Hess's Law states that enthalpy is a state function, meaning ΔH depends
only on the initial and final states, not the path taken. The enthalpy change is
determined by the difference in bond energies between reactants and products,
which reflects the nature of bonds broken and formed.
4. Which thermodynamic parameter measures the disorder or randomness of
a system?
A) Enthalpy
B) Entropy
C) Gibbs free energy
D) Heat capacity
E) Standard potential
,✓ B) Entropy
Rationale: Entropy (S) is the thermodynamic property that quantifies the degree of
disorder, randomness, or microscopic complexity in a system. Higher entropy
indicates greater disorder. The second law of thermodynamics states that the
entropy of an isolated system always increases for spontaneous processes.
5. A reaction with ΔH > 0 and ΔS > 0 is spontaneous at:
A) Low temperatures only
B) High temperatures only
C) All temperatures
D) No temperature
E) Only at equilibrium
✓ B) High temperatures only
Rationale: Using the Gibbs free energy equation ΔG = ΔH - TΔS, when both ΔH and
ΔS are positive, ΔG becomes negative (spontaneous) only when the TΔS term is
larger than ΔH, which occurs at high temperatures. At low temperatures, ΔH
dominates and ΔG remains positive (non-spontaneous).
6. What is the relationship between Gibbs free energy and spontaneity?
A) ΔG > 0 indicates a spontaneous reaction
B) ΔG < 0 indicates a spontaneous reaction
C) ΔG = 0 indicates a spontaneous reaction
D) ΔG has no relationship with spontaneity
E) ΔG = ΔH always
✓ B) ΔG < 0 indicates a spontaneous reaction
, Rationale: Gibbs free energy (ΔG) is the thermodynamic criterion for spontaneity.
When ΔG is negative, the reaction proceeds spontaneously in the forward direction.
When ΔG is positive, the reaction is non-spontaneous. When ΔG equals zero, the
system is at equilibrium.
7. At equilibrium, the value of ΔG is:
A) Maximum
B) Minimum
C) Zero
D) Positive
E) Negative
✓ C) Zero
Rationale: At chemical equilibrium, there is no net change in reactant or product
concentrations, and no net flow of free energy. Therefore, ΔG = 0 at equilibrium.
This is the condition that defines the equilibrium state.
8. Which of the following correctly expresses the equilibrium constant
expression for the reaction 2A + B ⇌ C + D?
A) K = [A]²[B]/[C][D]
B) K = [C][D]/[A]²[B]
C) K = [A][B]/[C][D]
D) K = [C]²[D]²/[A][B]
E) K = [A] + [B]/[C] + [D]
✓ B) K = [C][D]/[A]²[B]
Rationale: The equilibrium constant expression follows the law of mass action,
where the concentrations of products are in the numerator and reactants in the
| Complete Study Guide | Verified Practice
Questions, Correct Answers & Detailed
Explanations | Latest Exam Prep PDF
UNE GENERAL CHEMISTRY II MIDTERM 2026 | Complete Study Guide
• 200 verified practice questions with detailed explanations to reinforce mastery
of General Chemistry II concepts
• Study guide format with correct answers highlighted and rationales provided for
every question to support active learning and concept retention
1. Which of the following is defined as the heat absorbed or released at
constant pressure?
A) Enthalpy
B) Entropy
C) Gibbs free energy
D) Internal energy
E) Heat capacity
✓ A) Enthalpy
Rationale: Enthalpy (H) is specifically defined as the heat content of a system at
constant pressure. It is the state function that measures the total heat absorbed or
released during a chemical reaction at constant pressure, making it the most
relevant thermodynamic function for understanding reactions in open systems and
at atmospheric conditions.
2. What is the sign of ΔH for an endothermic reaction?
A) Positive
B) Negative
C) Zero
,D) Undefined
E) Variable depending on temperature
✓ A) Positive
Rationale: Endothermic reactions absorb heat from the surroundings, meaning
energy is added to the system. This results in a positive ΔH value. The opposite is
true for exothermic reactions, which release heat and have negative ΔH values.
3. According to Hess's Law, the enthalpy change of a reaction depends on:
A) The path taken from reactants to products
B) The nature of the chemical bonds broken and formed
C) Only the initial and final states
D) Both B and C
E) The temperature and pressure of the reaction
✓ D) Both B and C
Rationale: Hess's Law states that enthalpy is a state function, meaning ΔH depends
only on the initial and final states, not the path taken. The enthalpy change is
determined by the difference in bond energies between reactants and products,
which reflects the nature of bonds broken and formed.
4. Which thermodynamic parameter measures the disorder or randomness of
a system?
A) Enthalpy
B) Entropy
C) Gibbs free energy
D) Heat capacity
E) Standard potential
,✓ B) Entropy
Rationale: Entropy (S) is the thermodynamic property that quantifies the degree of
disorder, randomness, or microscopic complexity in a system. Higher entropy
indicates greater disorder. The second law of thermodynamics states that the
entropy of an isolated system always increases for spontaneous processes.
5. A reaction with ΔH > 0 and ΔS > 0 is spontaneous at:
A) Low temperatures only
B) High temperatures only
C) All temperatures
D) No temperature
E) Only at equilibrium
✓ B) High temperatures only
Rationale: Using the Gibbs free energy equation ΔG = ΔH - TΔS, when both ΔH and
ΔS are positive, ΔG becomes negative (spontaneous) only when the TΔS term is
larger than ΔH, which occurs at high temperatures. At low temperatures, ΔH
dominates and ΔG remains positive (non-spontaneous).
6. What is the relationship between Gibbs free energy and spontaneity?
A) ΔG > 0 indicates a spontaneous reaction
B) ΔG < 0 indicates a spontaneous reaction
C) ΔG = 0 indicates a spontaneous reaction
D) ΔG has no relationship with spontaneity
E) ΔG = ΔH always
✓ B) ΔG < 0 indicates a spontaneous reaction
, Rationale: Gibbs free energy (ΔG) is the thermodynamic criterion for spontaneity.
When ΔG is negative, the reaction proceeds spontaneously in the forward direction.
When ΔG is positive, the reaction is non-spontaneous. When ΔG equals zero, the
system is at equilibrium.
7. At equilibrium, the value of ΔG is:
A) Maximum
B) Minimum
C) Zero
D) Positive
E) Negative
✓ C) Zero
Rationale: At chemical equilibrium, there is no net change in reactant or product
concentrations, and no net flow of free energy. Therefore, ΔG = 0 at equilibrium.
This is the condition that defines the equilibrium state.
8. Which of the following correctly expresses the equilibrium constant
expression for the reaction 2A + B ⇌ C + D?
A) K = [A]²[B]/[C][D]
B) K = [C][D]/[A]²[B]
C) K = [A][B]/[C][D]
D) K = [C]²[D]²/[A][B]
E) K = [A] + [B]/[C] + [D]
✓ B) K = [C][D]/[A]²[B]
Rationale: The equilibrium constant expression follows the law of mass action,
where the concentrations of products are in the numerator and reactants in the
