Transcript cont. - High Point Regional School District

Weather Unit
Investigation II:
Heating Matter
Lesson 1: Hot Enough
Lesson 2: Full of Hot Air
Lesson 3: Absolute Zero
Lesson 4: It’s Only a Phase
Lesson 5: The Heat is On
Lesson 6: Hot Cement
Weather Unit – Investigation II
Lesson 1:
Hot Enough
ChemCatalyst
The weather forecast in Tokyo, Japan
calls for a 60% chance of precipitation
with highs reaching 30C, while in
Washington DC the weather forecast
calls for a 70% chance of precipitation
with highs reaching 50F.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
• Which city will be warmer? Explain
your thinking.
• Do you think it will rain or snow in
either of the two cities? Explain your
reasoning.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
The Big Question
• How is temperature measured?
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
You will be able to:
• Understand the relationship between
Celsius and Fahrenheit.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Activity
Purpose: In this lesson, you will
examine how changes in volume of a
liquid with temperature can be used to
create a thermometer.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
Materials: (for each pair of students)
Small glass vial (about 2-dram size)
Stopper with one hole to fit into the vial
(or a septum with a hole)
Clear plastic straw that fits into the hole
in the stopper
Small amount of Vaseline to lubricate the
stopper and the straw
3 250-mL beakers
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
Water at room temperature with food
coloring added
Hot plate
Ice
Sharpie® pens to mark the straw
Metric ruler – small
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Making Sense
• What is happening to the water in the
vial to make it move up and down the
straw at different temperatures?
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
Height vs. Temperature of a Liquid
Height in cm
8
7
6
5
0
50
100
150
200
250
Degrees Fahrenheit (°F)
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
Degrees Fahrenheit vs. Celsius
250
Degrees Fahrenheit (°F)
200
150
100
50
0
-50
-20
0
20
40
60
80
100
120
Degrees Celsius (°C)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Notes
°C vs. °F
The relationship between C and F is:
F = 9/5 (C) + 32
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Check-In
• The temperature is 37C in Spain in
July. How does this compare with body
temperature, which is 98.6F?
• Will 37°C feel warm or cold? Explain
your reasoning.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Wrap-Up
• Liquids expand upon heating and
contract upon cooling.
• The change in volume of a liquid can
be used to measure temperature
changes.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Weather Unit – Investigation II
Lesson 2:
Full of Hot Air
ChemCatalyst
Meteorologists recognize that warm air
rises. Use this observation to answer the
questions below.
• Which has a larger volume, warm air
or cold air? Assume equal masses.
Explain your thinking.
• Which is denser, warm air or cold air?
Explain your thinking.
• Which molecules are moving faster,
those in warm air or those in cold air?
Explain your thinking.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
The Big Question
• What is the relationship between the
volume and temperature of a fixed
amount of gas?
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
You will be able to:
• Describe the change in volume and
density as temperature increases.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Activity
Purpose: The purpose of this lesson is to
allow you to observe and record volume
changes in a gas as a result of temperature
changes.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
Part I: Qualitative observations
Materials: (per pair of students)
test tube
test tube holder
beaker of room temperature water with
food coloring added to the water
beaker with water to place on hot plate
and boil water
hot plate
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
Part II: Quantitative observations
Materials: (per pair of students)
thermometer
1.5 mm capillary tube closed on one end
2 small rubber bands
ruler
permanent marker
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
Materials: (to be shared by four students)
oil in a small vial or beaker - about 1/4 to
1/2 inch of liquid
hot plate
beaker with water to place on hot plate
and boil water
beaker of ice
small beaker with rock salt
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
Part II Data
Temperature
(°C)
80
Height (mm)
65
67
40
63
25
60
10
55
–5
53
Volume (mm3)
71
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Making Sense
• Explain why the oil plug was moving
up the capillary tube.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Notes
Volume of Air
Temperature
(°C)
80
Height (mm)
Volume (mm3)
71
141
65
67
134
40
63
126
25
60
120
10
55
109
-5
53
106
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Notes (cont.)
Volume vs. Temperature of a Gas
Volume (mm3)
150
140
130
120
110
100
-20
-10
0
10
20
30
40
50
60
70
80
90
100
Temperature (°C)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Check-In
• What happens to the volume of a gas
as it is heated?
• What happens to the density of the gas
upon heating?
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Wrap-Up
• The volume of a fixed amount of gas
increases as the temperature
increases.
• When the volume of a gas increases
its density decreases.
• Because warm air expands, it is less
dense, and it rises. Likewise, cool air
contracts, it is denser, and it sinks.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Weather Unit – Investigation II
Lesson 3:
Absolute Zero
ChemCatalyst
The lowest recorded temperature in the
solar system was on Triton, a moon of
Neptune, and was recorded to be –235C.
• Do you think carbon dioxide would be a
solid, liquid, or gas at this temperature?
Explain your reasoning.
• As the temperature gets lower and lower,
the volume of a gas gets smaller and
smaller. What do you think happens to
the motions of the molecules?
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Notes
• Conversion between degrees Kelvin
and degrees Celsius:
K= 273 + °C
• Absolute zero is the temperature at
which the volume of a gas and its
temperature are both zero. Absolute
zero is only found on the Kelvin scale
and is equivalent to –273 ˚C.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
The Big Question
• Why is the Kelvin scale useful when
working with gases?
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
You will be able to:
• Use Charles’s Law.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Activity
Part I: A quantity of gas was heated to
various temperatures. Each time the
temperature changed, the volume of the
gas was measured in milliliters. The
temperature was sometimes measured
in degrees Celsius and sometimes in
degrees Kelvin. Note that V represents
volume in the table and T represents
temperature.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Copy the following table into your notebook.
Fill in the remainder of the table:
Trial Temperature Temperature Volume Ratio: V/T Ratio: V/T
(C)
(K)
(mL) (for T in C) (for T in K)
1
10.0
500
2
50.0
570
3
100.0
660
4
200.0
840
5
556
1000
6
1111
2000
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
Part II: Imagine there are two hot air
balloons ready for launch. One hot air
balloon (balloon A) is large and the other
(balloon B) is small. The air in each
balloon is heated and the temperature
and volume of the gas is recorded. The
following graph shows the data for each
balloon.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
Balloon Volume vs. Temperature
Two Different Balloons
1000
Volume in mL
800
Container A
600
Container B
400
200
0
0
200
400
600
800
1000
Temperature (K)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Making Sense
• What is the volume of the balloon
described in Part III when the
temperature is 50°C? (Be sure to use
Kelvin.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Notes
Charles’s Law
• For a given mass, the volume of gas is
directly proportional to its Kelvin
temperature, if the pressure is kept
constant.
• In symbols, Charles’s Law states that if
P is constant, V/T stays constant as
long as T is measured in Kelvin.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Notes (cont.)
Balloon Volume vs. Temperature
Two Different Balloons
1000
Volume in mL
800
Container A
600
Container B
400
200
0
0
200
400
600
Temperature (K)
800
1000
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Notes (cont.)
Proportional analysis
V1/T1 = V2/T2
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Check-In
• What change in volume results if 60.0
mL of gas is cooled from 27.0C to
2.0C?
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Wrap-Up
• Charles’s Law can be described by the
formula V1/T1 = V2/T2 (provided the
temperature is measured in Kelvin)
• Absolute zero is the temperature at
which the volume of a gas is 0.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Weather Unit – Investigation II
Lesson 4:
It’s Only a Phase
ChemCatalyst
Suppose you put a pot of water on the
stove on “high” (about 350°F or 170C).
After the water boils for about ten
minutes, the temperature of the water
is 212°F.
• What is happening to the water?
• Why is the temperature of the water
212°F and not 350°F like the stove?
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
The Big Question
• What happens to the temperature of
water as it is heated?
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
You will be able to:
• Describe what happens to water as it
is heated.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Activity
Purpose: This lesson allows you to track
the temperature of water over time as
heat is going into the system.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
Materials:
250 mL beaker
Ice cubes
Thermometers
Oven mitts or hot pads
Hot plate
Ring stand and clamp to hold the
thermometer (optional)
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
Remember:
• During this experiment do not let the
thermometer touch the glass while you
are measuring the temperature of the
water, otherwise you will be measuring
the temperature of the glass and not
the water. You may use a clamp to
hold the thermometer if this is helpful.
• Use the mitts to avoid getting burned
once the water starts to boil.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
Record every minute for 30 minutes
Temperature
Time
Phase
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
Heating curve of Water: Temperature vs. Time
120
Temperature (°C)
100
80
60
40
20
0
-20
0
2
4
6
8
10
12
14
16
18
20
Time (minutes)
Use a separate piece of graph paper.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Making Sense
• Why do you think the graph is not a
straight line?
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
Heating Curve of Water
120
“bo ili ng po int”
or boili ng
temperature
Temperature (°C)
100
80
60
40
“melti ng po int”
or melti ng
temperature
20
0
-20
0
2
4
6
8
10
12
14
16
18
20
Time (minutes)
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
SUBLIMATION
SOLID
MELTING
FREEZING
BOILING / EVAPORATION
LIQUID
GAS
CONDENSATION
SOLIDIFICATION
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Notes
Fixed temperatures for a given substance:
• Melting/ Freezing point is a fixed
temperature where solid and liquid
coexist
• Boiling point is a fixed temperature
where liquid and gas coexist
• Sublimation / Solidification point is a
fixed temperature where solid and gas
coexist
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Notes (cont.)
Processes that occur at various
temperatures:
• Evaporation / Condensation is a
change from liquid to gas or gas to liquid
at temperatures below the boiling point.
• Precipitation is the term meteorologists
use to describe the condensation of
water vapor to form snow, sleet, or rain.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Check-In
• How long was the water in your beaker
at 100°C?
• Describe what was happening to the
water during this time.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Wrap-Up
• The heating curve of water beginning
with ice and ending with boiling water
shows a sloped line, a plateau, another
sloped line, and another plateau.
• The two plateaus show that the
temperature remains constant when
ice melts and water boils.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Weather Unit – Investigation II
Lesson 5:
The Heat is On
ChemCatalyst
Below is a graph showing the heating
curve of water.
• Describe what is happening during the
flat portions of the graph.
• How can heat be going into the system
and the temperature still stay the
same?
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
120
Temperature (°C)
100
80
60
40
20
0
-20
0
2
4
6
8
10
12
14
16
18
20
Time (minutes)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
The Big Question
• Why does the temperature stay the
same when you add heat to melting ice
or boiling water?
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
You will be able to:
• Explain why the temperature of ice
water does not immediately go up
when heated.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Activity
Purpose: This lesson processes the
heating curve of water in greater detail,
examining what is happening at each
stage.
Heating curve of water
A graph of the heating curve for water is
shown below. The graph is not to scale
but it is drawn to emphasize differences
in the amount of time required for each
of the 5 steps.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
120
100
ƒ
¦
boili ng temperature
80
¬
60
40
20
0
-20
¡
¿
0
melti ng temperature
Time
Copy this table into your notebook.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Making Sense
• Explain in your own words what you
think the difference is between heat
and temperature.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
Heating Curve of Water
120
100
80
boiling
¬
60
melting
40
warming
20
0
-20
ƒ
¦
¡
¿
0
Time
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Notes
• Heat is the transfer of energy between
two objects due to temperature
differences.
• Temperature is a scale that measures
the average kinetic energy (or speed)
of particles in a substance due to their
random motion.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Check-In
• If you heat a glass of ice water will its
temperature automatically go up?
• When will its temperature increase?
Explain.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Wrap-Up
• When ice is in the process of melting
(changing phase) the temperature
remains at 0°C. When water is in the
process of boiling (changing phase),
the temperature remains constant at
100°C.
• If only one phase of a substance is
present in a system that is being
heated, the temperature of that
substance increases.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
• Temperature is a measure of the
kinetic energy of the molecules of a
substance.
• Heat is a process of energy transfer,
the direction of which is determined by
temperature.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Weather Unit – Investigation II
Lesson 6:
Hot Cement
ChemCatalyst
Below are the average daily temperatures for
two cities in the United States:
San Francisco, California:
Winter: 50 ˚F
Spring: 56 ˚F
Summer: 59 ˚F
Fall: 61 ˚F
Average annual rainfall: 19 inches
Average annual snowfall: 0 inches
Wichita, Kansas:
Winter: 38 ˚F
Spring: 55 ˚F
Summer: 93 ˚F
Fall: 63 ˚F
30 inches
15.5 inches
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
• What differences do you notice about
the data for the two cities?
• What could account for the differences
in average temperature?
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
The Big Question
• How do the specific heat capacities of
water and soil affect the climate of the
earth?
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
You will be able to:
• Understand how heat capacity affects
climate.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Notes
• Water and soil are two of the most
common substances on the planet.
• Each substance will be heated for 15-20
minutes.
• At the end of that time you will compare
the temperature of the two substances.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Notes (cont.)
• The amount of heat needed to raise
the temperature of 1 gram of a
substance by 1˚Celsius is called the
specific heat capacity.
• Heat is measured in calories. It takes
one calorie to raise the temperature of
one gram of water 1˚C. Thus, the
specific heat capacity of water is 1.00
cal / gram ˚C.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Activity
Purpose: This activity allows you to
compare the specific heat capacities of
various substances.
Heating substances in the sun
The following table shows the
temperature after 10.0 g of four different
substances have been in direct sunlight
for up to 60 minutes.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
Time (min)
Air (°C)
25°C
Water
(°C)
25°C
Sand
(°C)
25°C
Metal
(°C)
25°C
0 (initial)
15.0
28.9°C
26.2°C
30°C
35°C
30.0
32.5°C
27.5°C
35°C
45°C
45.0
36.2°C
28.8°C
40°C
55°C
60.0
40°C
30°C
45°C
65°C
X axis
Y axis
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
Temperature vs Heating Time
70
Temperature (°C)
60
50
40
30
20
0
10
20
30
40
50
60
Time (minutes)
Use a separate piece of graph paper.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Making Sense
• Use specific heat capacity to explain
why some regions have very mild
climates and other regions have
severe climates with a wide range of
temperatures.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
(cont.)
70
metal
Temperature (°C)
60
50
sand
40
air
30
water
20
0
10
20
30
40
50
60
Time (minutes)
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Check-In
Consider the climate on the Hawaiian
Islands. The temperature is 37°C in July.
• Do you expect the temperature to be
different in January? Why or why not?
© 2004 Key Curriculum Press.
Unit 3 • Investigation II
Wrap-Up
• The specific heat capacity of a substance is
the heat required to raise the temperature of
one gram of that substance by one degree
Celsius.
• The high specific heat capacity of water has
an effect on the climate of the planet. Places
close to oceans will experience more
moderate ranges in temperature. Places far
from bodies of water will experience more
extreme fluctuations in temperature.
© 2004 Key Curriculum Press.
Unit 3 • Investigation II