1. Phase Changes and Heating Curve of Water

2. Temperature Temperature – the measure of particles moving
Higher temperature = Fast moving particles
Lower temperature = Slow moving particles

3. Thermal Energy
Thermal Energy – TOTAL energy of all particles (KE + PE)
ALL matter has thermal energy

4. Heat
Heat – the amount of thermal energy that is transferred to an object or area
EX: Cooking an egg
(Hot stove  frying pan  egg

5. 4 States of Matter
Solid
Liquid
Gas
Plasma
States of Matter

6. Phase Properties Phase Atoms Packed Energy Solid Closest Little Liquid
Moderate
Gas
Far
A Lot

7. As heat is added or taken, matter can change its state or phase
Phase Changes

8. Phase Changes Changes States Involved Melting Solid → Liquid Freezing
Liquid → Solid
Vaporization
Liquid → Gas
Condensation
Gas → Liquid
Sublimation
Solid → Gas
Deposition
Gas → Solid

9. Phase Changes

10. Heat Transmission Endothermic – Heat goes INTO an object or reaction.
Exothermic – Heat is RELEASED from an object or reaction.

11. Heating Curve of Water
Water is matter that can go through ALL the different phase changes

12. Heating Curve of Water
There is NO temperature change during a Change of Phase!

13. What is the phase change called from B to C?
Which letters represent a gas?
What is the phase change called from D to E?
Which letters represent a solid?
What is the phase change called from E to D?
What is the phase change called from C to B?
What is the temperature change when a phase change occurs?

14. Heat of Fusion
Energy required to change a solid at its melting point to a liquid.
It is unique for every substance.
For water, the heat of fusion = 6 kJ/mol

15. Heat of Vaporization
The energy required to change a liquid at its boiling point to a gas.
It is unique for every substance.
For water, the heat of fusion = 41 kJ/mol

16. Professor Dave
Phase Changes Video