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ACS GEN CHEM 2 EXAM / ACTUAL ACS GEN CHEM 2 FINAL
EXAM 2026/2027 BANK QUESTIONS WITH DETAILED
VERIFIED ANSWERS EXAM QUESTIONS WILL COME
FROM HERE (100% CORRECT ANSWERS A+ GRADED
1. Which of the following is a colligative property of a solution?
A) Color
B) Density
C) Vapor pressure lowering
D) Electrical conductivity
Answer: C
Explanation: Colligative properties depend only on the number of
solute particles, not their identity. Vapor pressure lowering is
colligative; color, density, and conductivity are not purely colligative.
2. The vapor pressure of a pure solvent is 100 torr at a certain
temperature. After adding a nonvolatile solute, the vapor pressure is 95
torr. What is the mole fraction of the solvent?
A) 0.05
B) 0.95
C) 1.00
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D) 0.90
Answer: B
Explanation: Raoult’s law: P_solution = X_solvent * P°_solvent. 95 =
X_solvent * 100 → X_solvent = 0.95.
3. Which of the following will have the highest boiling point?
A) 0.1 m NaCl
B) 0.1 m CaCl2
C) 0.1 m glucose
D) 0.1 m AlCl3
Answer: D
Explanation: Boiling point elevation depends on the van’t Hoff factor i.
AlCl3 dissociates into 4 ions (i≈4), CaCl2 into 3, NaCl into 2, glucose i=1.
4. The freezing point depression constant Kf for water is 1.86 °C/m.
What is the freezing point of a 0.50 m CaCl2 solution? Assume 100%
dissociation.
A) -0.93 °C
B) -1.86 °C
C) -2.79 °C
D) -3.72 °C
Answer: C
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Explanation: ΔTf = i * Kf * m = 3 * 1.86 * 0.50 = 2.79 °C depression.
Freezing point = 0.00 - 2.79 = -2.79 °C.
5. Osmotic pressure (π) is given by π = iMRT. Which statement is
correct?
A) M is molality
B) R is the gas constant
C) T is in Celsius
D) i is always 1 for electrolytes
Answer: B
Explanation: M is molarity, R = 0.0821 L·atm/(mol·K), T in Kelvin, i > 1
for electrolytes.
6. A solution contains 12.0 g of urea (molar mass 60 g/mol) in 200. g of
water. What is the molality?
A) 0.10 m
B) 0.50 m
C) 1.00 m
D) 2.00 m
Answer: C
Explanation: Moles urea = 12.0/60 = 0.200 mol. Mass water = 0.200 kg.
Molality = 0.200/0.200 = 1.00 m.
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7. Which colligative property is most sensitive to small changes in
solute concentration?
A) Boiling point elevation
B) Freezing point depression
C) Vapor pressure lowering
D) Osmotic pressure
Answer: D
Explanation: Osmotic pressure has the largest magnitude per unit
concentration because π = iMRT, and R and T are typically not small.
8. The rate of a reaction doubles when temperature increases from 300
K to 310 K. What is the approximate activation energy?
A) 10 kJ/mol
B) 20 kJ/mol
C) 50 kJ/mol
D) 100 kJ/mol
Answer: C
Explanation: Using Arrhenius: ln(k2/k1) = (Ea/R)(1/T1 - 1/T2). ln2 =
(Ea/8.314)(1/300 - 1/310) → Ea ≈ 53.6 kJ/mol.
9. For a first‑order reaction, the half‑life is 30 s. What is the rate
constant?
A) 0.0231 s^-1
ACS GEN CHEM 2 EXAM / ACTUAL ACS GEN CHEM 2 FINAL
EXAM 2026/2027 BANK QUESTIONS WITH DETAILED
VERIFIED ANSWERS EXAM QUESTIONS WILL COME
FROM HERE (100% CORRECT ANSWERS A+ GRADED
1. Which of the following is a colligative property of a solution?
A) Color
B) Density
C) Vapor pressure lowering
D) Electrical conductivity
Answer: C
Explanation: Colligative properties depend only on the number of
solute particles, not their identity. Vapor pressure lowering is
colligative; color, density, and conductivity are not purely colligative.
2. The vapor pressure of a pure solvent is 100 torr at a certain
temperature. After adding a nonvolatile solute, the vapor pressure is 95
torr. What is the mole fraction of the solvent?
A) 0.05
B) 0.95
C) 1.00
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D) 0.90
Answer: B
Explanation: Raoult’s law: P_solution = X_solvent * P°_solvent. 95 =
X_solvent * 100 → X_solvent = 0.95.
3. Which of the following will have the highest boiling point?
A) 0.1 m NaCl
B) 0.1 m CaCl2
C) 0.1 m glucose
D) 0.1 m AlCl3
Answer: D
Explanation: Boiling point elevation depends on the van’t Hoff factor i.
AlCl3 dissociates into 4 ions (i≈4), CaCl2 into 3, NaCl into 2, glucose i=1.
4. The freezing point depression constant Kf for water is 1.86 °C/m.
What is the freezing point of a 0.50 m CaCl2 solution? Assume 100%
dissociation.
A) -0.93 °C
B) -1.86 °C
C) -2.79 °C
D) -3.72 °C
Answer: C
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Explanation: ΔTf = i * Kf * m = 3 * 1.86 * 0.50 = 2.79 °C depression.
Freezing point = 0.00 - 2.79 = -2.79 °C.
5. Osmotic pressure (π) is given by π = iMRT. Which statement is
correct?
A) M is molality
B) R is the gas constant
C) T is in Celsius
D) i is always 1 for electrolytes
Answer: B
Explanation: M is molarity, R = 0.0821 L·atm/(mol·K), T in Kelvin, i > 1
for electrolytes.
6. A solution contains 12.0 g of urea (molar mass 60 g/mol) in 200. g of
water. What is the molality?
A) 0.10 m
B) 0.50 m
C) 1.00 m
D) 2.00 m
Answer: C
Explanation: Moles urea = 12.0/60 = 0.200 mol. Mass water = 0.200 kg.
Molality = 0.200/0.200 = 1.00 m.
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7. Which colligative property is most sensitive to small changes in
solute concentration?
A) Boiling point elevation
B) Freezing point depression
C) Vapor pressure lowering
D) Osmotic pressure
Answer: D
Explanation: Osmotic pressure has the largest magnitude per unit
concentration because π = iMRT, and R and T are typically not small.
8. The rate of a reaction doubles when temperature increases from 300
K to 310 K. What is the approximate activation energy?
A) 10 kJ/mol
B) 20 kJ/mol
C) 50 kJ/mol
D) 100 kJ/mol
Answer: C
Explanation: Using Arrhenius: ln(k2/k1) = (Ea/R)(1/T1 - 1/T2). ln2 =
(Ea/8.314)(1/300 - 1/310) → Ea ≈ 53.6 kJ/mol.
9. For a first‑order reaction, the half‑life is 30 s. What is the rate
constant?
A) 0.0231 s^-1
