1. PHASE CHANGES

2. Kinetic Theory Kinetic = motion
Particles in a gas are considered to be hard, small spheres with an insignificant volume.
The motion of particles in a gas is rapid, constant, and random.

3. All collisions between particles in a gas are perfectly elastic.
Particles in a gas only interact when they collide.

4. Temperature (in kelvins, K) is directly proportional to the average kinetic energy of the particles of a substance.
Objects expand when heated because of increased vibrational motion.

5. Gas pressure is caused by the collisions of particles with an object (wall).

6. Atmospheric pressure results from the weight of air above an object.
Higher altitudes have less atmospheric pressure.

7. Standard atmospheric pressure is:
1 atm = kPa = 760 mm Hg
A barometer measures atmospheric pressure.

8. Liquids Condensed states of matter – solids and liquids
In liquids KE is high enough for molecules to flow and take the shape of their container.

9. Intermolecular attractions give liquids a definite volume.

10. Evaporation – changing from liquid to vapor at the surface - cooling process

11. Condensation – warming process

12. Vapor pressure – pressure in a bubble

13. Boiling point – temperature at which the vapor pressure equals external pressure on the liquid

15. Gas Stoichiometry
1 mol of a gas at standard temperature and pressure (STP) = 22.4 L

16. Volume – Volume Problems
2NO + O2  2NO2
How many liters of nitrogen dioxide are produced when 34 L of O2 react?

17. What cancels?

18. Volume – Moles Problems
2NO + O2  2NO2
How many moles of nitrogen dioxide are produced when 34 L of O2 react?

19. Solids Phase Changes
The general properties of solids reflect the orderly arrangement and fixed locations of their particles.
Crystal - regular geometric arrangement

20. Allotropes - (diamond, graphite) 2 or more different molecular forms of the same element in the same physical state

21. Amorphous - no geometric pattern

22. Phase changes
Sublimation - solid to vapor
Vaporization - liquid to vapor (evaporation or boiling)
Solidification - liquid to solid
Melting - solid to liquid

23. A) 0.016C, 0.61 kPa
B) S, L, V
C) 100C; 0C

24. Ch 13 Review Notes
Atmospheric pressure affects the boiling point of a liquid.

25. STP – standard temperature and pressure - 0C and 1 atm
1 atm = 760 mm Hg so…

26. Absolute zero = 0 K is the temperature the motion of particles theoretically ceases.

27. Triple point – conditions ( temperature & pressure) at which solid, liquid, and vapor (gas) can exist in equilibrium.

28. Solids are more dense than liquids and gases.
Sublimation can occur because solids have a vapor pressure.