1. States of Matter & Phase Changes

2. IMAFs KE vs. States of Matter main difference between phases is…
GAS
LIQUID
SOLID
main difference between phases is…
the distance between particles…
…which depends on two competing quantities: KE
(kinetic energy of the particles)
IMAFs
(intermolecular attractive forces between particles)
vs.

3. K = oC + 273 no KE Temp↑ as KE↑ Temperature
average KE is directly proportional to temperature in Kelvin
Temp↑ as KE↑
373 K
273 K
K = oC + 273
no KE
0 K
absolute zero
–273oC
–460oF

4. SOLID - definite shape - definite volume - low kinetic energy
VLC – media file (Changes of State)
- low kinetic energy
- particles vibrate in place

5. LIQUID - indefinite shape - definite volume - higher kinetic energy
VLC – media file (Changes of State)
- higher kinetic energy
- particles flow

6. GAS - indefinite shape - indefinite volume - highest kinetic energy
VLC – media file (Changes of State)
- highest kinetic energy
- expands to fill container
compressible

7. GAS SOLID LIQUID Phase Changes condensation sublimation deposition
Energy Absorbed
Energy Released
GAS
condensation
sublimation
deposition
vaporization
Video – Changes of State
melting
SOLID
LIQUID
freezing

8. energy + liquid gas vaporization: evaporation: l to g at surface
boiling:
l to g beneath surface

9. Equilibrium Open system
More molecules are evaporating than are condensing
The phases are NOT in equilibrium

10. Equilibrium Closed system
the rate of vaporization can equal the rate of condensation.
(dynamic equilibrium)

11. Quick Quiz.
1) The average kinetic energy of the particles in a substance is directly proportional to the
A) molar mass
B) density
C) temperature
D) size 11

12. A) attract each other significantly B) are spaced relatively far apart
Quick Quiz.
2) Compared to liquids and solids, gases are easily compressed because the particles in a gas…
A) attract each other significantly
B) are spaced relatively far apart
C) are extremely small
D) move in constant, random motion 12

13. Quick Quiz.
3) What is –88oC in Kelvin temperature?
A) 185 K
B) 361 K
C) –361 K
D) 273 K
K = oC + 273
K = – 13

14. Quick Quiz.
4) Put a cup of water on a table. A process that will occurs is…
A) evaporation.
B) condensation.
C) BOTH A and B
D) NONE of the above