1. Table of Contents Chapter Preview 3.1 States of Matter
3.2 Changes of State
3.3 The Behavior of Gases

2. Chapter Preview Questions
1. The space that matter fills is called
a. pressure.
b. area.
c. volume.
d. mass.

3. Chapter Preview Questions
1. The space that matter fills is called
a. pressure.
b. area.
c. volume.
d. mass.

4. Chapter Preview Questions
2. Which of the following describes a solid?
a. definite volume but no definite shape
b. definite shape and definite volume
c. neither definite shape nor definite volume
d. definite shape but no definite volume

5. Chapter Preview Questions
2. Which of the following describes a solid?
a. definite volume but no definite shape
b. definite shape and definite volume
c. neither definite shape nor definite volume
d. definite shape but no definite volume

6. Chapter Preview Questions
3. Which of the following describes a liquid?
a. definite volume but no definite shape
b. definite shape and definite volume
c. neither definite shape nor definite volume
d. definite shape but no definite volume

7. Chapter Preview Questions
3. Which of the following describes a liquid?
a. definite volume but no definite shape
b. definite shape and definite volume
c. neither definite shape nor definite volume
d. definite shape but no definite volume

8. Chapter Preview Questions
4. Which of the following describes a gas?
a. definite volume but no definite shape
b. definite shape and definite volume
c. neither definite shape nor definite volume
d. definite shape but no definite volume

9. Chapter Preview Questions
4. Which of the following describes a gas?
a. definite volume but no definite shape
b. definite shape and definite volume
c. neither definite shape nor definite volume
d. definite shape but no definite volume

10. Section 1: States of Matter
California Content Standard 8.3.e: Students know that in solids the atoms are closely locked in position and can only vibrate; in liquids the atoms and molecules are more loosely connected and can collide with and move past one another; and in gases the atoms and molecules are free to move independently, colliding frequently.

11. Solids
The particles in a solid are closely locked in position and can only vibrate.

12. Solids
Solids that are made up of crystals are called crystalline solids.
In amorphous solids, the particles are not arranged in a regular pattern.

13. Liquids
Compared to particles in a solid, the particles in a liquid are more loosely connected and can collide with and move past one another.

14. Gases
In gases, the atoms and molecules are free to move independently, colliding frequently.

15. Section 2: Changes of State
California Content Standard 8.3.d: Students know the states of matter (solid, liquid, gas) depend on molecular motion.
California Content Standard 8.5.d: Students know physical processes include freezing and boiling, in which a material changes form with no chemical reaction.

16. Changes Between Solid and Liquid
The change in state from a solid to a liquid is called melting.
When a substance melts, the particles in the solid vibrate so fast that they break free from their fixed positions.
A change from solid to liquid involves an increase in thermal energy.

17. Changes Between Solid and Liquid
The change from a liquid to a solid is called freezing.
When a substance freezes, the particles in the liquid move so slowly that they begin to take on fixed positions.
The change from liquid to solid involves a decrease in thermal energy.

18. Changes Between Liquid and Gas
The change from a liquid to a gas is called vaporization.
Vaporization that takes place only on the surface of a liquid is called evaporation.

19. Changes Between Liquid and Gas
Boiling occurs when a liquid changes to a gas below its surface as well as at the surface.
The temperature at which a liquid boils is called its boiling point.
The boiling point of a substance depends on the pressure of the air above it.
The lower the pressure, the less energy needed for the particles of the liquid to escape into the air.
Boiling point is a characteristic property of a substance.

20. Changes Between Liquid and Gas
Condensation
The change in state from a gas to a liquid.
During condensation, the particles in a gas lose enough thermal energy to form a liquid.
Condensation is the reverse of vaporization.
Clouds in the atmosphere form due to condensation.

21. Changes Between Liquid and Gas
Sublimation
During sublimation, particles of a solid do not pass through the liquid state as they form a gas.
Dry ice, or solid carbon dioxide, is an example of compound that does not turn to liquid at normal atmospheric pressures.

22. Temperature and Changes of State
A beaker of ice at –10ºC was slowly heated to 110ºC. The graph shows how the temperature of the water changed over time.

23. Temperature and Changes of State
Reading Graphs:
What two variables are plotted on the graph?
Temperature (ºC) on the y-axis, time (minutes) on the x-axis

24. Temperature and Changes of State
Reading Graphs:
What is happening to the temperature of the water during segment C of the graph?
The temperature is rising from 0ºC to 100ºC.

25. Temperature and Changes of State
Interpreting Data:
What does the temperature value for segment B represent? For segment D?
Segment B: melting point of ice; segment D: boiling point of water

26. Temperature and Changes of State
Drawing Conclusions:
What change of state is occurring during segment B of the graph? During segment D?
Change from solid to liquid; change from liquid to gas

27. Section 3: The Behavior of Gases
California Content Standard 8.3.d: Students know the states of matter (solid, liquid, gas) depend on molecular motion.
California Content Standard 8.9.e: Construct appropriate graphs from data and develop quantitative statements about the relationships between variables.

28. Measuring Gases
When working with a gas, it is helpful to know its volume, temperature, and pressure. Volume Temperature
Because gas particles move and fill the space available, the volume of a gas is the same as the volume of its container. Temperature is a measure of the average energy of motion of the particles of matter. The faster the particles are moving, the greater their energy and the higher the temperature.

29. Measuring Gases
When working with a gas, it is helpful to know its volume, temperature, and pressure. Pressure
Pressure of a gas is the force of its outward push divided by the area of the walls of the container. Pressure is often measured in units of pascals (Pa) or kilopascals (kPa). It can also be measured in atmospheres (atm) or millimeters of Mercury (mm Hg).

30. A Change in Pressure
A punctured basketball deflates as gas particles begin to escape.

31. Temperature and Volume – Charles’s Law
When the temperature of a gas increases at constant pressure, its volume increases.
The variables are directly proportional to each other, forming a straight line that passes through the origin.

32. Temperature and Volume – Charles’s Law
When the temperature of a gas is decreased at constant pressure, the volume decreases.

33. Gas Law Problems – Charles’ Law
Temperature Conversion
Equation
Kelvin (K) = °C + 273
Example: 0 °C = 273 K
20 °C = 293 K
V1/T1 = V2/T2
V1 = Volume 1
T1 = Temperature 1
V2 = Volume 2
T2 = Temperature 2

34. Gas Law Problems – Charles’ Law
Example 1: Calculate the decrease in temperature when 2.00 Liters of gas at a temperature of 20 °C is compressed to 1.00 Liters. V1/T1 = V2/T2 20 °C = 293 Kelvin 2 L = 1L 293 K x 2x = 293 x = Kelvin

35. Gas Law Problems – Charles’ Law
Example 2: Calculate the increase in volume when 600 mL of air at a temperature of 20 °C is heated to 60 °C. V1/T1 = V2/T2 20 °C = 293 Kelvin 60 °C = 333 Kelvin 600 mL = x 293 K 333 K 293x = (600)(333) 293x = 199,800 x = 682 mL

36. Gas Law Problems – Charles’ Law
Example 3: Check for Understanding A gas occupies 900 mL at a temperature of 27 °C. What is the volume at 132 °C? V1/T1 = V2/T2 27 °C = 300 Kelvin 132 °C = 405 Kelvin 900 mL = x 300 K 405 K 300x = (900)(405) 300x = 364,500 x = 1,215 mL

37. Gas Law Problems – Charles’ Law
Example 4: Check for Understanding What change in volume results if 60 mL of gas is cooled from 33 °C to 5 °C? V1/T1 = V2/T2 33 °C = 306 Kelvin 5 °C = 278 Kelvin 60 mL = x 306 K 278 K 306x = (60)(278) 306x = 16,680 x = 54.5 mL

38. Pressure and Volume – Boyle’s Law
When the pressure of a gas at constant temperature is increased, the volume of the gas decreases.

39. Pressure and Volume – Boyle’s Law
When the pressure is decreased, the volume increases.
Gas pressure is inversely proportional to volume at constant temperature. The product of the two variables is a constant.

40. Gas Law Problems – Boyle’s Law
Pressure Conversion
Equation
1 atm = 760 mm Hg = 101,325 Pa
Example: 2 atm = 1,520 mm Hg
2 atm = 202,650 Pa
(P1)(V1) = (P2)(V2)
P1 = Pressure 1
V1 = Volume 1
P2 = Pressure 2
V2 = Volume 2

41. Gas Law Problems – Boyle’s Law
Example 1:
A gas occupies 12.3 liters at a pressure of 40 mm Hg. What is the volume when the pressure is increased to 60 mm Hg?
(P1)(V1) = (P2)(V2)
(12.3)(40) = (60)(x)
492 = 60x
x = 8.2 liters

42. Gas Law Problems – Boyle’s Law
Example 2:
If a gas occupies 3.60 liters at a pressure of 1 atm, what will its volume be at a pressure of 2.50 atm?
(P1)(V1) = (P2)(V2)
(1)(3.60) = (2.50)(x)
3.60 = 2.50x
x = 1.44 liters

43. Gas Law Problems – Boyle’s Law
Example 3: Check for Understanding
If a gas occupies 1.56 liters at a pressure of 1 atm, what will its volume be at a pressure of 3 atm?
(P1)(V1) = (P2)(V2)
(1)(1.56) = (3)(x)
1.56 = 3x
x = .52 liters

44. Gas Law Problems – Boyle’s Law
Example 4: Check for Understanding
If a gas occupies 600 mL at a pressure of 8 atm, what will its volume be at a pressure of 2 atm?
(P1)(V1) = (P2)(V2)
(8)(600) = (2)(x)
4,800 = 2x
x = 2,400 mL

45. Pressure and Temperature
When a gas is heated, the particles move faster and collide more often with each other and with the walls of their container. The pressure of the gas increases.

46. Graphing Gas Behavior
In an experiment, the temperature of a gas at a constant volume was varied. Gas pressure (in kilopascals) was measured after each 5-kelvin change in temperature. The data from the experiment are shown in the table.

47. Graphing Gas Behavior Graphing
Use the data to make a line graph. Plot temperature on the horizontal axis with a scale from 270 K to 300 K. Plot pressure on the vertical axis with a scale from 0 kPa to 25 kPa. (1 kPa = 1,000 Pa)

48. Graphing Gas Behavior Interpreting Data
What was the manipulated variable in this experiment?
Changing the temperature of a gas at constant volume changes its pressure in a similar way.

49. Graphing Gas Behavior Interpreting Data
What kind of trend do the data show?
Pressure increases with temperature.

50. Graphing Gas Behavior Drawing Conclusions
What happens to the pressure of a gas when temperature is increased at constant volume?
Gas pressure increases.