Questions on Intermolecular Forces
Multiple-Choice Questions: Intermolecular Forces
1. Which of the following is NOT an intermolecular force?
A) London dispersion force
B) Dipole-dipole interaction
C) Hydrogen bond
D) Covalent bond
E) Ion-dipole interaction
2. Intermolecular forces are responsible for determining which of the following?
A) Atomic number
B) Molecular geometry
C) Physical properties such as boiling and melting points
D) Types of chemical bonds within a molecule
E) Molar mass
3. Which of the following molecules exhibits only London dispersion forces?
A) H₂O
B) CH₄
C) HCl
D) NH₃
E) HF
4. What causes London dispersion forces?
A) Permanent dipoles
B) Ionic attractions
C) Temporary fluctuations in electron distribution
D) Hydrogen atoms bonded to fluorine
E) Fixed charges on atoms
5. Which molecule experiences hydrogen bonding?
A) CH₄
B) CO₂
C) H₂S
D) HF
E) Cl₂
6. Dipole-dipole interactions occur between molecules that are:
A) Nonpolar
B) Polar
C) Ionic
D) Metallic
E) Gaseous only
7. Which of the following has the strongest intermolecular forces?
A) London dispersion
B) Dipole-dipole
C) Hydrogen bonding
D) Covalent bonding
E) Ion-dipole
8. Ion-dipole forces are important in which of the following situations?
A) Mixing two nonpolar substances
B) Dissolving an ionic compound in water
C) Bonding of covalent molecules
D) Boiling of noble gases
E) Solidification of metals
9. Which type of force is responsible for the liquefaction of noble gases?
A) Covalent bonding
B) Dipole-dipole interaction
C) Ion-dipole force
D) London dispersion force
E) Hydrogen bonding
10. Hydrogen bonding is a particularly strong form of:
A) Ionic bonding
B) Dipole-dipole interaction
C) Metallic bonding
D) London dispersion force
E) Covalent bonding
11. Which of the following has the weakest intermolecular forces?
A) NH₃
B) H₂O
C) He
D) HF
E) CH₃OH
12. Which factor increases the strength of London dispersion forces?
A) Lower molecular weight
B) Higher electronegativity
C) Smaller surface area
D) Greater number of electrons
E) Hydrogen bonding
13. Which pair of molecules will have dipole-dipole interactions?
A) CH₄ and O₂
B) HCl and H₂O
C) N₂ and CO₂
D) CH₄ and He
E) Br₂ and I₂
14. What kind of intermolecular force is most important in CH₃OH?
A) London dispersion
B) Dipole-dipole
C) Hydrogen bonding
D) Metallic bonding
E) Ionic bonding
15. Why does water have a higher boiling point than methane (CH₄)?
A) Larger molar mass
B) Greater London forces
C) Presence of hydrogen bonding in water
D) Water is nonpolar
E) Methane has ionic bonds
16. Which intermolecular force is present in all substances?
A) Dipole-dipole
B) Ion-dipole
C) Hydrogen bonding
D) London dispersion
E) Ionic bonding
17. Which of these substances would likely have the highest boiling point?
A) Ne
B) CH₄
C) NH₃
D) H₂
E) O₂
18. Which of the following best describes ion-dipole forces?
A) Interaction between two dipoles
B) Forces between ions in a crystal
C) Forces between an ion and the partial charge of a polar molecule
D) Interaction of two nonpolar molecules
E) Covalent bond between ions
19. Which of the following increases as intermolecular forces increase?
A) Vapor pressure
B) Volatility
C) Boiling point
D) Rate of evaporation
E) Compressibility
20. Which one of the following is a consequence of strong intermolecular forces in a liquid?
A) Low viscosity
B) High surface tension
C) Low boiling point
D) High vapor pressure
E) Rapid evaporation
Answers with Explanations
1. D) Covalent bonds are intramolecular (within molecules), not intermolecular.
2. C) Intermolecular forces determine physical properties like boiling/melting point.
3. B) CH₄ is nonpolar and only has London dispersion forces.
4. C) London forces result from temporary dipoles caused by electron movement.
5. D) HF forms hydrogen bonds (H directly bonded to F).
6. B) Dipole-dipole interactions occur between polar molecules.
7. E) Ion-dipole interactions are the strongest intermolecular forces.
8. B) Ion-dipole forces occur when ionic compounds dissolve in polar solvents like water.
9. D) London dispersion forces allow noble gases to condense into liquids.
10. B) Hydrogen bonding is a special type of dipole-dipole force.
11. C) He (helium) is a noble gas with very weak London dispersion forces.
12. D) More electrons → more polarizable → stronger London dispersion forces.
13. B) Both HCl and H₂O are polar → they interact via dipole-dipole forces.
14. C) CH₃OH has an –OH group, enabling hydrogen bonding.
15. C) Water has hydrogen bonding, methane does not.
16. D) London dispersion forces are found in all molecules.
17. C) NH₃ exhibits hydrogen bonding, increasing its boiling point.
18. C) Ion-dipole is between an ion and polar molecule's dipole.
19. C) Stronger intermolecular forces → higher boiling points.
20. B) Strong intermolecular forces → high surface tension.
Share Online!
