UNE GENERAL CHEMISTRY II MIDTERM 2026 EXAM
with Questions and Answers/Plus a Rationale
Updated 2026 A+/Instant Download PDF
EXAM COVERAGE - 1. Intermolecular Forces and Liquids -
2. Properties of Solutions - 3. Chemical Kinetics - 4. Chemical
Equilibrium - 5. Acids and Bases - 6. Aqueous Equilibria
1. Which of the following substances exhibits hydrogen bonding as its primary intermolecular force
in the liquid state?
A. H2S
B. CH3OH
C. CH3CH2CH3
D. PH3
CORRECT ANSWER : B
Rationale: Methanol contains an -OH group directly bonded to an electronegative oxygen atom,
allowing for strong hydrogen bonding. H2S, propane, and phosphine lack this bond type and
rely on weaker dipole-dipole or dispersion forces.
2. What is the primary factor responsible for the exceptionally high boiling point of water
compared to other Group 16 hydrides?
A. The molar mass of water
B. London dispersion forces between oxygen atoms
C. Extensive intermolecular hydrogen bonding networks
D. The ionic character of the O-H covalent bond
CORRECT ANSWER : C
Rationale: Water molecules form a robust three-dimensional hydrogen bonding network that
requires significantly more thermal energy to disrupt during phase changes. Molar mass and
ionic character are not the primary drivers of this anomaly.
,3. Which of the following molecules has the highest polarizability?
A. HF
B. HCl
C. HBr
D. HI
CORRECT ANSWER : D
Rationale: Polarizability increases down a group as the electron cloud becomes larger and more
loosely held by the nucleus. Iodine has the largest atomic radius and most diffuse electron cloud
among the halogens listed.
4. Which phase change is exothermic?
A. Melting
B. Vaporization
C. Condensation
D. Sublimation
CORRECT ANSWER : C
Rationale: Condensation involves transitioning from a gas to a liquid, which releases energy to
the surroundings as intermolecular forces are formed. Melting, vaporization, and sublimation
are endothermic processes requiring energy input.
5. The vapor pressure of a liquid increases with increasing temperature primarily because:
A. Atmospheric pressure decreases
B. Molecular weight decreases
C. Average kinetic energy of molecules increases
D. Intermolecular forces become stronger
CORRECT ANSWER : C
, Rationale: As temperature rises, more molecules possess sufficient kinetic energy to overcome
intermolecular attractive forces and escape into the gas phase. Intermolecular forces and
molecular weight remain constant for a given substance at varying temperatures.
6. Which substance would you expect to have the lowest surface tension at room temperature?
A. H2O
B. CH3OH
C. CH3CH2CH2CH3
D. HOCH2CH2OH
CORRECT ANSWER : C
Rationale: Butane is a nonpolar hydrocarbon held together only by weak London dispersion
forces, resulting in low surface tension. Water and the alcohols exhibit strong hydrogen bonding,
leading to much higher surface tensions.
7. What type of crystalline solid is represented by dry ice (solid CO2)?
A. Ionic solid
B. Metallic solid
C. Molecular solid
D. Covalent network solid
CORRECT ANSWER : C
Rationale: Solid carbon dioxide consists of discrete nonpolar molecules held together in a
crystal lattice by relatively weak intermolecular forces. It does not form an ionic, metallic, or
extended covalent network.
8. Which solid is classified as a covalent network solid?
A. NaCl
B. Cu
C. SiO2
D. Ice
, CORRECT ANSWER : C
Rationale: Silicon dioxide (quartz) consists of a continuous three-dimensional network of
covalent bonds between silicon and oxygen atoms. NaCl is ionic, copper is metallic, and ice is
molecular.
9. The enthalpy of vaporization for a substance is generally greater than its enthalpy of fusion
because:
A. Molecules are closer together in the gas phase
B. Melting involves breaking intramolecular bonds
C. Vaporization requires completely overcoming intermolecular forces
D. Fusion requires greater temperature changes
CORRECT ANSWER : C
Rationale: Vaporization requires separating molecules completely from one another into the gas
phase, breaking all intermolecular attractions. Fusion only requires giving molecules enough
mobility to slide past each other in the liquid state.
10. A phase diagram shows that a substance's triple point is at 1.0 atm and 50 °C. What is true at
temperatures below 50 °C?
A. The liquid phase cannot exist
B. The solid phase cannot melt
C. The liquid phase cannot exist at pressures below the triple point
D. The gas phase must condense immediately
CORRECT ANSWER : C
Rationale: At pressures below the triple point pressure, the solid transitions directly to gas via
sublimation without passing through the liquid phase. The liquid phase is thermodynamically
unstable below this pressure.
11. Which aqueous solution has the highest boiling point elevation assuming complete dissociation
for ionic solutes?
A. 0.1 m NaCl
B. 0.1 m C6H12O6
with Questions and Answers/Plus a Rationale
Updated 2026 A+/Instant Download PDF
EXAM COVERAGE - 1. Intermolecular Forces and Liquids -
2. Properties of Solutions - 3. Chemical Kinetics - 4. Chemical
Equilibrium - 5. Acids and Bases - 6. Aqueous Equilibria
1. Which of the following substances exhibits hydrogen bonding as its primary intermolecular force
in the liquid state?
A. H2S
B. CH3OH
C. CH3CH2CH3
D. PH3
CORRECT ANSWER : B
Rationale: Methanol contains an -OH group directly bonded to an electronegative oxygen atom,
allowing for strong hydrogen bonding. H2S, propane, and phosphine lack this bond type and
rely on weaker dipole-dipole or dispersion forces.
2. What is the primary factor responsible for the exceptionally high boiling point of water
compared to other Group 16 hydrides?
A. The molar mass of water
B. London dispersion forces between oxygen atoms
C. Extensive intermolecular hydrogen bonding networks
D. The ionic character of the O-H covalent bond
CORRECT ANSWER : C
Rationale: Water molecules form a robust three-dimensional hydrogen bonding network that
requires significantly more thermal energy to disrupt during phase changes. Molar mass and
ionic character are not the primary drivers of this anomaly.
,3. Which of the following molecules has the highest polarizability?
A. HF
B. HCl
C. HBr
D. HI
CORRECT ANSWER : D
Rationale: Polarizability increases down a group as the electron cloud becomes larger and more
loosely held by the nucleus. Iodine has the largest atomic radius and most diffuse electron cloud
among the halogens listed.
4. Which phase change is exothermic?
A. Melting
B. Vaporization
C. Condensation
D. Sublimation
CORRECT ANSWER : C
Rationale: Condensation involves transitioning from a gas to a liquid, which releases energy to
the surroundings as intermolecular forces are formed. Melting, vaporization, and sublimation
are endothermic processes requiring energy input.
5. The vapor pressure of a liquid increases with increasing temperature primarily because:
A. Atmospheric pressure decreases
B. Molecular weight decreases
C. Average kinetic energy of molecules increases
D. Intermolecular forces become stronger
CORRECT ANSWER : C
, Rationale: As temperature rises, more molecules possess sufficient kinetic energy to overcome
intermolecular attractive forces and escape into the gas phase. Intermolecular forces and
molecular weight remain constant for a given substance at varying temperatures.
6. Which substance would you expect to have the lowest surface tension at room temperature?
A. H2O
B. CH3OH
C. CH3CH2CH2CH3
D. HOCH2CH2OH
CORRECT ANSWER : C
Rationale: Butane is a nonpolar hydrocarbon held together only by weak London dispersion
forces, resulting in low surface tension. Water and the alcohols exhibit strong hydrogen bonding,
leading to much higher surface tensions.
7. What type of crystalline solid is represented by dry ice (solid CO2)?
A. Ionic solid
B. Metallic solid
C. Molecular solid
D. Covalent network solid
CORRECT ANSWER : C
Rationale: Solid carbon dioxide consists of discrete nonpolar molecules held together in a
crystal lattice by relatively weak intermolecular forces. It does not form an ionic, metallic, or
extended covalent network.
8. Which solid is classified as a covalent network solid?
A. NaCl
B. Cu
C. SiO2
D. Ice
, CORRECT ANSWER : C
Rationale: Silicon dioxide (quartz) consists of a continuous three-dimensional network of
covalent bonds between silicon and oxygen atoms. NaCl is ionic, copper is metallic, and ice is
molecular.
9. The enthalpy of vaporization for a substance is generally greater than its enthalpy of fusion
because:
A. Molecules are closer together in the gas phase
B. Melting involves breaking intramolecular bonds
C. Vaporization requires completely overcoming intermolecular forces
D. Fusion requires greater temperature changes
CORRECT ANSWER : C
Rationale: Vaporization requires separating molecules completely from one another into the gas
phase, breaking all intermolecular attractions. Fusion only requires giving molecules enough
mobility to slide past each other in the liquid state.
10. A phase diagram shows that a substance's triple point is at 1.0 atm and 50 °C. What is true at
temperatures below 50 °C?
A. The liquid phase cannot exist
B. The solid phase cannot melt
C. The liquid phase cannot exist at pressures below the triple point
D. The gas phase must condense immediately
CORRECT ANSWER : C
Rationale: At pressures below the triple point pressure, the solid transitions directly to gas via
sublimation without passing through the liquid phase. The liquid phase is thermodynamically
unstable below this pressure.
11. Which aqueous solution has the highest boiling point elevation assuming complete dissociation
for ionic solutes?
A. 0.1 m NaCl
B. 0.1 m C6H12O6
