4.4 Intermolecular Forces

Which of the following molecules primarily interacts through induced dipole interactions?

A. H2O

B. CH4

C. HCl

D. NaCl

Which factor does NOT affect the strength of van der Waals forces?

A. Size of the molecule

B. Shape of the molecule

C. Charge of the molecule

D. Number of electrons in the molecule

Which of the following is NOT a requirement for the formation of hydrogen bonds?

A. Presence of a hydrogen atom

B. Presence of a highly electronegative atom

C. Presence of a metal atom

D. A significant difference in electronegativity between the bonded atoms

Which of the following molecules can form hydrogen bonds?

A. CH4

B. NH3

C. Cl2

D. Ne

Why is water (H2O) a liquid at room temperature while methane (CH4) is a gas?

A. Water has ionic bonds

B. Methane has stronger covalent bonds

C. Water can form hydrogen bonds

D. Methane has a larger molecular size

a) Define the term "induced dipole interactions" and explain how they arise in non-polar molecules. [3]

b) Why are induced dipole interactions also referred to as "van der Waals forces"? [2]

a) Describe the factors that affect the strength of van der Waals forces in non-polar molecules. [3]

b) Given two non-polar molecules, one larger and one smaller, which one would you expect to have stronger van der Waals forces and why? [2]

a) What is a "hydrogen bond", and how does it differ from other types of dipole-dipole interactions? [3]

b) Explain the significance of hydrogen bonding in the structure of water. [2]

a) Explain the difference between a dipole-dipole interaction and an induced dipole interaction. [3]

b) Why do non-polar molecules, which lack permanent dipoles, still exhibit van der Waals forces? [2]

c) How do the strengths of these interactions compare to covalent bonds? [2]

a) What is the significance of hydrogen bonding in the structure of DNA? [3]

b) Why are hydrogen bonds crucial for the double helix structure of DNA? [2]

c) How do hydrogen bonds compare in strength to covalent bonds and other intermolecular forces? [3]