Teacher+PowerPoint_+Changes+of+State+and+Thermodynamics

Topic: Changes of State and Thermodynamics Focus Question: Why doesn't a bowl of hot soup spontaneously freeze?

Heat of Fusion: Energy required to change a solid to a liquid at its melting point.
Heat of Vaporization: Energy required to change a liquid to a gas at its boiling point.
First Law of Thermodynamics: Energy cannot be created or destroyed, only transformed.
Heat Engine: Device converting thermal energy into mechanical energy.
Second Law of Thermodynamics: Energy tends to disperse; entropy increases.
Entropy: Measure of energy dispersion in a system.
Joule (J): SI unit of work and energy.

States of Matter: Solids, liquids, and gases.
Heating Ice and Water:
- As thermal energy is added, ice melts into water and subsequently boils to vapor, with constant temperature during melting and boiling

First Law: ΔU = Q - W; reiterates conservation of energy.
Heat Engines: Convert thermal energy to mechanical energy; waste heat represents unconverted energy.
Refrigeration & Heat Pumps: Remove heat from a cold area.

Energy dispersion requires a temperature difference; entropy increases with added thermal energy.

Understanding phase changes involves heat of fusion/vaporization, specific heat, and energy transformation principles from the first and second laws of thermodynamics.