1. Kinetic Energy Attractions vs. Unit 12: States of Matter
GAS
LIQUID
SOLID
main difference between phases is…
the distance between particles…
…which depends on two competing factors:
Kinetic Energy
(Kinetic Energy of the particles)
Attractions
(Attractions between particles, IMAFs)
vs.

2. Kinetic-Molecular Theory (of Gases)
5 Parts of KMT
have negligible volume (are tiny) compared to the great distance between
have negligible attractions because they are so far apart
10 x

3. are in constant, random motion
5 Parts of KMT
are in constant, random motion
Elastic (like marbles colliding)
have perfectly elastic collisions (transfer KE without loss, like billiard balls)
as opposed to Inelastic (like clay balls colliding)

4. K = oC + 273.15 no KE 5 Parts of KMT ↑Temp as ↑KEavg 0 K absolute zero
average KE (which already considers mass) is directly proportional to temperature
↑Temp as ↑KEavg
373 K
273 K
K = oC
no KE
0 K
absolute zero
–273oC.15
–459.67oF

5. Working against attractive forces
SOLID
LIQUID
GAS
video clip
low KE, vibrates
higher KE,
flows
highest KE,
expands
VLC – media file (Changes of State)
compressible

6. Phase Changes

7. liquid solid + energy liquid solid + energy
freezing:
l to s (lose KE)
liquid solid + energy
Forces of attraction between molecules cause them to get closer, then vibrate about fixed positions and form a solid.
liquid solid + energy
melting:
s to l (gain KE)

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

9. gas liquid + energy condensation: g to l (lose KE)
warm water vapor in air
ice cubes
cold water inside glass
condensed drops outside glass
Is water in glass cooler or warmer ?

10. sublimation:
s to g (gain KE)
energy + solid gas
deposition:
g to s (lose KE)
solid gas + energy

11. 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

12. 1) According to the kinetic molecular theory, gas particles...
Quick Quiz!
1) According to the kinetic molecular theory, gas particles...
A) are attracted to each other.
B) are in constant random motion.
C) have the same kinetic energy .
D) have a significant volume. 12

13. Quick Quiz.
2) The average kinetic energy of the particles in a substance is directly proportional to the
A) molar mass
B) density
C) temperature
D) size 13

14. A) attract each other significantly B) are spaced relatively far apart
Quick Quiz.
3) 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 14

15. Quick Quiz.
4) What is –88oC in Kelvin temperature?
A) 185 K
B) 361 K
C) –361 K
D) 273 K
K = oC + 273
K = – 15

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