UNE GENERAL CHEMISTRY II EXAM WITH
WELL-VERIFIED QUESTIONS AND ANSWERS||
ALREADY GRADED A+|| LATEST UPDATE 2026
Section 1: Intermolecular Forces & Phase Changes
1. Which intermolecular force is present in ALL molecules, regardless
of polarity?
Answer: London dispersion forces. They arise from temporary
fluctuations in electron distribution that create instantaneous dipoles.
2. What type of intermolecular force is primarily responsible for the
unusually high boiling point of water?
Answer: Hydrogen bonding. Water's high boiling point is due to
extensive hydrogen bonding between molecules, where H is bonded to O.
3. 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
Answer: B. Methanol (CH₃OH) contains an -OH group directly bonded
to an electronegative oxygen atom, allowing for strong hydrogen
bonding.
4. A hydrogen bond is characterized by:
Answer: A strong dipole-dipole attraction between a hydrogen atom
bonded to N, O, or F and another N, O, or F atom. The partially positive
hydrogen is attracted to a lone pair on an electronegative atom in another
molecule.
5. A cohesive force is:
Answer: The intermolecular force that attracts identical molecules.
Adhesive forces attract different molecules together.
6. Which of the following molecules has the highest polarizability? (A)
HF (B) HCl (C) HBr (D) HI
, Answer: D. HI. Polarizability increases down a group as the electron
cloud becomes larger and more loosely held by the nucleus.
7. Which phase change is exothermic? (A) Melting (B) Vaporization (C)
Condensation (D) Sublimation
Answer: C. Condensation releases energy to the surroundings as
intermolecular forces are formed.
8. The vapor pressure of a liquid increases with increasing temperature
primarily because:
Answer: The average kinetic energy of molecules increases. More
molecules possess sufficient energy to overcome intermolecular attractive
forces and escape into the gas phase.
9. Which substance would you expect to have the lowest surface tension
at room temperature? (A) H₂O (B) CH₃OH (C) CH₃CH₂CH₂CH₃ (D)
HOCH₂CH₂OH
Answer: C. Butane (CH₃CH₂CH₂CH₃) is a nonpolar hydrocarbon held
together only by weak London dispersion forces, resulting in low surface
tension.
10.What type of crystalline solid is represented by dry ice (solid CO₂)?
Answer: Molecular solid. It consists of discrete nonpolar molecules held
together in a crystal lattice by relatively weak intermolecular forces.
11.Which solid is classified as a covalent network solid? (A) NaCl (B) Cu
(C) SiO₂ (D) Ice
Answer: C. Silicon dioxide (quartz) consists of a continuous three-
dimensional network of covalent bonds.
12.Viscosity is a measure of:
Answer: A liquid's resistance to flow. It is influenced by the strength of
intermolecular forces, molecular size and shape, and temperature.
13.Which of the following will have the strongest dipole-dipole
attractions? (A) NCl₃ (B) CCl₄ (C) BCl₃ (D) Cl₂
Answer: A. NCl₃ is asymmetrical and has a significant dipole moment.
CCl₄ and Cl₂ are nonpolar, and BCl₃ is trigonal planar and nonpolar.
14.What is the primary factor responsible for the exceptionally high
boiling point of water compared to other Group 16 hydrides?
Answer: Extensive intermolecular hydrogen bonding networks. Water
molecules form a robust three-dimensional hydrogen bonding network
that requires significantly more thermal energy to disrupt.
, 15.The enthalpy of vaporization is the energy required to:
Answer: Convert a liquid to a gas. It is the energy needed to overcome
the intermolecular forces holding the molecules in the liquid phase.
16.Which intermolecular force is the strongest?
Answer: Ion-dipole forces are generally the strongest, followed by
hydrogen bonding, dipole-dipole, and London dispersion forces.
17.What is a phase diagram?
Answer: A graph showing the conditions of temperature and pressure at
which a substance exists in solid, liquid, and gaseous phases.
18.What is the triple point on a phase diagram?
Answer: The point where all three phases (solid, liquid, gas) coexist in
equilibrium.
19.What is the critical point on a phase diagram?
Answer: The point above which a liquid and gas are indistinguishable,
forming a supercritical fluid.
20.Which of the following has the highest boiling point? (A) CH₄ (B)
CCl₄ (C) CHCl₃ (D) H₂O
Answer: D. H₂O has the highest boiling point due to hydrogen bonding.
21.What is the relationship between intermolecular forces and boiling
point?
Answer: Stronger intermolecular forces result in higher boiling points
because more energy is required to separate the molecules.
22.What is the relationship between intermolecular forces and vapor
pressure?
Answer: Stronger intermolecular forces result in lower vapor pressure
because fewer molecules can escape from the liquid surface.
23.Which intermolecular force is present in all molecules, regardless of
polarity? (Repeated for emphasis)
Answer: London dispersion forces.
24.What is surface tension?
Answer: The energy required to increase the surface area of a liquid by a
unit amount. It is caused by the unbalanced intermolecular forces at the
surface.
25.What is capillary action?
Answer: The ability of a liquid to flow in narrow spaces without the
WELL-VERIFIED QUESTIONS AND ANSWERS||
ALREADY GRADED A+|| LATEST UPDATE 2026
Section 1: Intermolecular Forces & Phase Changes
1. Which intermolecular force is present in ALL molecules, regardless
of polarity?
Answer: London dispersion forces. They arise from temporary
fluctuations in electron distribution that create instantaneous dipoles.
2. What type of intermolecular force is primarily responsible for the
unusually high boiling point of water?
Answer: Hydrogen bonding. Water's high boiling point is due to
extensive hydrogen bonding between molecules, where H is bonded to O.
3. 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
Answer: B. Methanol (CH₃OH) contains an -OH group directly bonded
to an electronegative oxygen atom, allowing for strong hydrogen
bonding.
4. A hydrogen bond is characterized by:
Answer: A strong dipole-dipole attraction between a hydrogen atom
bonded to N, O, or F and another N, O, or F atom. The partially positive
hydrogen is attracted to a lone pair on an electronegative atom in another
molecule.
5. A cohesive force is:
Answer: The intermolecular force that attracts identical molecules.
Adhesive forces attract different molecules together.
6. Which of the following molecules has the highest polarizability? (A)
HF (B) HCl (C) HBr (D) HI
, Answer: D. HI. Polarizability increases down a group as the electron
cloud becomes larger and more loosely held by the nucleus.
7. Which phase change is exothermic? (A) Melting (B) Vaporization (C)
Condensation (D) Sublimation
Answer: C. Condensation releases energy to the surroundings as
intermolecular forces are formed.
8. The vapor pressure of a liquid increases with increasing temperature
primarily because:
Answer: The average kinetic energy of molecules increases. More
molecules possess sufficient energy to overcome intermolecular attractive
forces and escape into the gas phase.
9. Which substance would you expect to have the lowest surface tension
at room temperature? (A) H₂O (B) CH₃OH (C) CH₃CH₂CH₂CH₃ (D)
HOCH₂CH₂OH
Answer: C. Butane (CH₃CH₂CH₂CH₃) is a nonpolar hydrocarbon held
together only by weak London dispersion forces, resulting in low surface
tension.
10.What type of crystalline solid is represented by dry ice (solid CO₂)?
Answer: Molecular solid. It consists of discrete nonpolar molecules held
together in a crystal lattice by relatively weak intermolecular forces.
11.Which solid is classified as a covalent network solid? (A) NaCl (B) Cu
(C) SiO₂ (D) Ice
Answer: C. Silicon dioxide (quartz) consists of a continuous three-
dimensional network of covalent bonds.
12.Viscosity is a measure of:
Answer: A liquid's resistance to flow. It is influenced by the strength of
intermolecular forces, molecular size and shape, and temperature.
13.Which of the following will have the strongest dipole-dipole
attractions? (A) NCl₃ (B) CCl₄ (C) BCl₃ (D) Cl₂
Answer: A. NCl₃ is asymmetrical and has a significant dipole moment.
CCl₄ and Cl₂ are nonpolar, and BCl₃ is trigonal planar and nonpolar.
14.What is the primary factor responsible for the exceptionally high
boiling point of water compared to other Group 16 hydrides?
Answer: Extensive intermolecular hydrogen bonding networks. Water
molecules form a robust three-dimensional hydrogen bonding network
that requires significantly more thermal energy to disrupt.
, 15.The enthalpy of vaporization is the energy required to:
Answer: Convert a liquid to a gas. It is the energy needed to overcome
the intermolecular forces holding the molecules in the liquid phase.
16.Which intermolecular force is the strongest?
Answer: Ion-dipole forces are generally the strongest, followed by
hydrogen bonding, dipole-dipole, and London dispersion forces.
17.What is a phase diagram?
Answer: A graph showing the conditions of temperature and pressure at
which a substance exists in solid, liquid, and gaseous phases.
18.What is the triple point on a phase diagram?
Answer: The point where all three phases (solid, liquid, gas) coexist in
equilibrium.
19.What is the critical point on a phase diagram?
Answer: The point above which a liquid and gas are indistinguishable,
forming a supercritical fluid.
20.Which of the following has the highest boiling point? (A) CH₄ (B)
CCl₄ (C) CHCl₃ (D) H₂O
Answer: D. H₂O has the highest boiling point due to hydrogen bonding.
21.What is the relationship between intermolecular forces and boiling
point?
Answer: Stronger intermolecular forces result in higher boiling points
because more energy is required to separate the molecules.
22.What is the relationship between intermolecular forces and vapor
pressure?
Answer: Stronger intermolecular forces result in lower vapor pressure
because fewer molecules can escape from the liquid surface.
23.Which intermolecular force is present in all molecules, regardless of
polarity? (Repeated for emphasis)
Answer: London dispersion forces.
24.What is surface tension?
Answer: The energy required to increase the surface area of a liquid by a
unit amount. It is caused by the unbalanced intermolecular forces at the
surface.
25.What is capillary action?
Answer: The ability of a liquid to flow in narrow spaces without the
