2. Prime time 9/26/16 Three States of Water
Water is an abundant substance on Earth. It can be found as a solid, a liquid, and as a gas called water vapor.
1. How many words can you think of to describe solid water?
2. Where is most of the liquid water on Earth found? Where is most of the water vapor found?
3. Describe a natural event you have observed when water changed from a liquid to a solid, and when water changed from a liquid to a vapor.

3. Test make ups
Come see me before school, during lunch, or after school to make up chapter 2 test so I can pass those back this week
If you did not get to finish test and spoke to me come suring one of these times as well

4. Gas Laws rap winners Based on content and presentation:
Period 2 – Group 3
Period 3 – Group 4
Period 7 - Group 2

5. Gas Laws Homework review game
Question 1
Convert the following temperatures to C.
a) 67 K
b) 1671 K

6. Question 2
Convert a pressure of mm Hg to the equivalent pressure in pascals
(Pa).

7. Question 3
A sample of nitrogen gas has a volume of 478 cm3 and a pressure of kPa. What volume would the gas occupy at 88.2 kPa if the temperature
remains constant?

8. Question 4
8.98 dm3 of hydrogen gas is collected at 38.8 °C. Find the volume the gas will occupy at °C if the pressure remains constant.

9. Question 5

10. Notes

11. 3.3 Phase Changes
Phase Change= the reversible physical change that occurs when a substance changes from one state to another
Six common phase changes:
Melting
Freezing
Vaporization
Condensation
Sublimation
deposition

12. Prime time 9/28/16 1. What is happening at each letter in the diagram?
Hint A is solid ice
2. Does condensation occur? Why yes or why not?

13. Phase changes video Take notes !

14. Phase Changes
Figure 16

15. 3.3 B. Temperature & Phase Changes:
1. Temperature does NOT raise or lower during a phase change… it stays constant
2. Graphs showing phase changes look like stairsteps
Energy & Phase Changes
During a phase change energy is transferred between substance and surroundings
Endothermic=the substance absorbs energy
Exothermic= the substance releases energy
Heat of Fusion= amount of energy absorbed during melting

16. Heating Curve for Naphthalene
Figure 16

17. Heating curve of H2O

18. Heating curve of H2O
Condensation Vaporization

19. Heating curve of H2O
Condensation Vaporization
Melting
Freezing

20. 3.3 Melting & Freezing: 1. Melting
a. Arrangement of molecules becomes more orderly during freezing and less orderly during melting
b. Energy absorbed during melting helps molecules overcome their “fixed” arrangement
c. After melting extra energy increases temp of substance
4. Freezing
a. As energy leaves during freezing the molecules move more slowly
b. Freezing occurs when molecules arrange in fixed arrangements (does not always need to be cold)

21. 3.3 Vaporization & Condensation:
Vaporization=substance changes from a liquid to a gas, is endothermic
Heat of vaporization= amount of energy absorbed during vaporization, varies between substances
Evaporation= change from a liquid to a gas at a temperature below the boiling point
Vapor pressure= pressure created in a closed container when evaporated molecules collide with container walls, increases temp,

22. 3.3
5. Boiling
a. liquid is heated until some molecules turn to a gas, these “bubbles” rise to the top of the liquid releasing the vapor
b. Boiling occurs when temperature raises vapor pressure to equal atmospheric pressure
Condensation= phase change when a gas becomes a liquid
Dew on grass, a “sweating” glass
Dewpoint= temp at which condensation will happen that day/night

23. 3.3
Sublimation & Deposition:
1. Sublimation= phase change where substance changes from solid to gas without going through liquid state
a. Endothermic
2. Deposition=when a substance changes from a gas to a solid without going through the liquid state
a. Exothermic
b. Frost on windows

24. Reading Strategy Summarizing a. liquid d. liquid e. gas f. gas
Section 3.3
Summarizing
a. liquid
d. liquid
e. gas
f. gas
b. liquid
c. gas

25. Exit pass 9/28/16 Fill in the endothermic/exothermic charts?
What makes something endothermis?

26. Exit Pass 9/26/16
What is the difference between sublimation and deposition?

27. Temperature remains constant until the phase change is complete