Melting and Boiling Points
Learning Objectives
- Students will be able to define melting point and boiling point
- Students will be able to explain how intermolecular forces affect melting and boiling points
- Students will be able to predict relative melting/boiling points based on molecular structure
Core Concepts
- melting_point
- boiling_point
- intermolecular_forces
- latent_heat_of_fusion
- latent_heat_of_vaporization
- normal_boiling_point
Formulas
$$Q_{fusion} = m L_f$$
Heat required to melt a substance
$$Q_{vap} = m L_v$$
Heat required to vaporize a substance
Units
| latent heat of fusion | L_f (J/kg) |
| latent heat of vaporization | L_v (J/kg) |
Interesting Fact
Some substances have extremely high melting points: tungsten melts at 3422°C and is used in light bulb filaments
Key Scientist
Anders Celsius
Used fixed points (melting and boiling of water) to define his temperature scale
Modern Research
Materials science designs substances with specific melting points for applications; phase change materials use melting/boiling for thermal energy storage.
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