AP Chemistry: Intermolecular Forces & Properties 3

Question 1

Which property of water is a direct consequence of hydrogen bonding?

Accepted Answer

High surface tension

Answer

Hydrogen bonds pull surface molecules together, producing high surface tension.

Question 2

Why is ice less dense than liquid water?

Accepted Answer

Hydrogen bonds form an open crystal lattice

Answer

Hydrogen bonding arranges water molecules into an open hexagonal lattice with more empty space.

Question 3

A liquid with a high vapor pressure at room temperature most likely has:

Accepted Answer

Weak intermolecular forces

Answer

Weak intermolecular forces let molecules escape easily, raising vapor pressure.

Question 4

Which substance is expected to have the highest boiling point?

Accepted Answer

C5H12 (pentane)

Answer

Pentane has the largest molar mass and most electrons, giving the strongest dispersion forces.

Question 5

Capillary action of water in a thin glass tube results from:

Accepted Answer

Adhesion and cohesion

Answer

Adhesion to glass and cohesion among water molecules together drive capillary rise.

AP Practice Test