Solids, Liquids, and Phase Transitions

Question 1

What is capillary action?

Answer 1

The attraction of the surface of a liquid to the surface of a solid

Tends to pull molecules upward along the surface of a tube against gravity

Basis of paper chromatography

Responsible for transportation of water through leaves and the formation of meniscus

Question 2

What is the definition of boiling point?

Answer 2

The point at which the liquid’s vapor pressure equals the atmospheric pressure

Question 3

What is the definition of the critical temperature?

Answer 3

The temperature above which the liquid phase of a substance cannot exist

Question 4

What is the definition of the critical pressure?

Answer 4

The minimum pressure required to liquefy a gas at its critical temperature

Question 5

What is sublimation?

Answer 5

The process in which solids vaporize directly without passing through the liquid phase. Examples: solid carbon dioxide, solid iodide

Question 6

Name three ways in which intermolecular forces differ from intramolecular forces

Answer 6

1. Intermolecular forces are generally weaker than covalent bonds
2. Intermolecular forces are much less directional than covalent bonds
3. Intermolecular forces operate at a longer range than covalent chemical bonds