Weather Unit
Investigation I:
Locating Matter
Lesson 1: Weather or Not
Lesson 2: Raindrops Keep Falling . . .
Lesson 3: Having a Melt Down
Lesson 4: It’s Sublime
Lesson 5: Water World
Weather Unit – Investigation I
Lesson 1:
Weather or Not
ChemCatalyst
Below are a picture and weather report
of a hurricane off the coast of Florida in
the United States.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
FORECAST FOR THE MIAMI AREA: The
tenth depression of the season in the Atlantic
has become Hurricane Jan. The center of Jan
is southeast of Florida. The maximum
sustained winds are near 120 miles per hour.
The estimated minimum central pressure is
28.5 inches. Skies over Miami are mostly
cloudy. The temperature is 35C / 95F with
(cont.)
90% humidity.
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
Jan is expected to drop as much as 10
inches of rain in the southern part of Florida
with rising temperature and humidity.
• What are hurricanes and what do you
think causes them?
• What is weather? What causes weather?
• How do meteorologists predict things like
hurricanes?
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
The Big Question
• What causes water to ‘cycle’ or move
around on the planet?
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
You will be able to:
• Explain what causes rain on the planet
Earth.
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Activity
Purpose: In this activity you will heat
and cool water in a flask with a balloon
attached. Your observations will help you
determine what makes the water “cycle.”
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
Materials: (for each team of two students)
250 mL Erlenmeyer flask
25 mL graduated cylinder
Medium sized party balloon
5 mL of water
Hot plate
Oven mitt
Bucket or large beaker with ice and water
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Making Sense
• Based on this experiment, explain
what causes water to “cycle” around
the planet?
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Notes
• Evaporation is the changing of a substance from
the liquid phase to the gas phase. Condensation
is the changing of a substance from the gas phase
to the liquid phase.
• Gas, liquid, and solid are three different phases of
matter. A phase change refers to the conversion
of a liquid to a gas or a solid, or vice versa.
• A physical change is one in which the form or
temperature of a substance is changed without
changing its chemical make-up.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Notes (cont.)
• Humidity is a measure of the amount
of water vapor (or gaseous water) in
the air.
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Check-In
Answer the following question:
• Using what you learned today about
the movement of water, explain what
causes rain on the planet Earth.
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Wrap-Up
• Weather is an interaction between the
sun (a heat source), the water on the
planet, the Earth’s surface, and the
Earth’s atmosphere.
• Water moves around through phase
changes.
• Phase changes affect the volume of
substances.
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Weather Unit – Investigation I
Lesson 2:
Raindrops Keep
Falling . . .
ChemCatalyst
Annual rainfall in the United States
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
• How much rain fell where you live?
• How is rainfall measured?
• What type of instrument or container is
used to measure rainfall?
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
The Big Question
• How do meteorologists keep track of
rainfall?
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
You will be able to:
• Relate volume of water to rainfall
amount.
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Activity
Purpose: This lesson introduces you to
precision in measurement and allows
you to explore measuring rainfall in
inches and milliliters.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
Materials: (per team of 2 students)
25 mL graduated cylinder
100 mL beaker
12 inch ruler
Water bottles (use plastic pipettes or
droppers if you do not have water
bottles)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Making Sense
Meteorologists can keep track of the
amount of rainfall by measuring either
the volume or the height of rainfall in a
rain gauge.
• If the amount of rainfall increases, do
both the volume and height of water in
the rain gauge keep track of this
increase? Explain your thinking.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
• What does the precision of measuring
height and volume depend on? Is there
a difference in the precision of
measuring height or volume? Explain
your thinking.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
Volume vs. Height of Water
25
Volume (mL)
20
15
10
5
0
0
0
1/0.52
11
11.5
1/2
22
22.5
1/ 2
3
3
33.5
1/2
44
Height (inches)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Notes
• Significant figures are the numbers one
can read off of an instrument or piece of
equipment, plus one more estimated
number. The glassware or instrument
being used in a measurement determines
how many significant figures can be
recorded.
55
50
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Notes (cont.)
Significant Figures
Glassware
Beaker
Erlenmeyer
Flask
Graduated
Cylinder
Graduated
Pipette
# of
decimal
places
0
0
reading: 10 number of
ml of liquid significant
figs
10 mL
2
10 mL
2
1
10.0 mL
3
2
10.00 mL
4
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Notes (cont.)
Measuring Rainfall Data
Height
(inches)
Volume
(milliliters)
0 in
7/8 in
1 7/8 in
2 7/8 in
3 7/8 in
0 mL
5 mL
10.0 mL 15.0 mL 20.0 mL
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Notes (cont.)
• Two quantities are proportional if a
graph of the two variables results in a
straight line that passes through the
origin (0, 0).
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Notes (cont.)
Volume vs. Height of Water
25
Volume (mL)
20
15
10
5
0
000
1/2
1/0.5
2
1 11 1 1/2
2
11.5
1 /2
2221/2 22.5
31/ 23 1/2
3
3
4 33.5
1 /2
44
Height (inches)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Check-In
Answer the following question:
• Suppose you find that 1.0 inch of
rainfall in a graduated cylinder has a
volume of 4.0 mL. What volume would
you measure for 2.0 inches of rainfall?
A) 4 mL B) 4.0 mL C) 4.00 mL
D) 8 mL E) 8.0 mL F) 8.00 mL
Explain your thinking.
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Wrap-Up
• Precision differences in measurements are a
result of the glassware or instrument that is
used.
• Significant figures are defined as all of the
numbers that can be read directly from an
instrument, plus one estimated number.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
• The volume of water in a cylindrical
container is directly proportional to the
height of the water.
• Graphs of two variables that are
proportional always lead to a straight
line through the origin.
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Weather Unit – Investigation I
Lesson 3:
Having a Melt Down
ChemCatalyst
• Meteorologists measure the snowpack
in the mountains to predict the amount
of water that will fill the lakes and
reservoirs. Do you think that 3
milliliters of snow is the same as 3
milliliters of rain? Explain your
reasoning.
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
The Big Question
• How can you convert from volume of
snowfall to volume of liquid water?
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
You will be able to:
• Understand the relationship between
density, mass and volume.
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Notes
• The density of a substance is the
slope of the line for a graph of mass
vs. volume.
Density = Mass/Volume
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Notes (cont.)
• The slope of a line is the change in y
divided by the change in x.
• For a line that goes through the origin
(0, 0), the slope is simply any value of
y divided by the corresponding value of
x.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Notes (cont.)
Slope = Density
Mass vs. Volume of Snow
100
Mass (g)
80
60
40
20
0
0
20
40
60
80
100
Volume (mL)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Activity
Purpose: This activity allows you to
relate volume of snowfall with volume of
rainfall by using the density of snowfall
and rainfall.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
Materials: (for each team of four students)
25 mL graduated cylinder
Scale
Water bottle (small dropper or plastic
pipette if water bottles are not available)
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
Mass of the graduated cylinder empty: ______
Measured
Mass of
water plus
graduated
cylinder (g)
Mass of
water (g)
Calculated
Volume of Mass/volume
water (mL)
(g/mL)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Making Sense
• Explain how you can relate volume of
snow to volume of rain.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
Mass vs. Volume of Water
25
Mass (g)
20
water
ice
15
10
snow
5
0
0
5
10
15
20
25
Volum e (mL)
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
m1 / V1 = slope = m2 / V2
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
Example Problem I:
Imagine you have a box that is 5.0 mL in
volume. What mass of ice will just fit this box?
Proportional Analysis
0.92 g = _ x __
1 mL
5.0 mL
Dimensional Analysis
5.0 mL
0.92 g = 4.6 g
1 mL
x = (0.92)(5.0) = 4.6 g
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
Example Problem II:
You have 20 grams of snow with a density of
0.50 g/mL. What volume does this snow
occupy (how many milliliters)?
Proportional Analysis
0.5 g
1 mL
=
20 g
x mL
Dimensional Analysis
20 g
1 mL
= 40 mL
0.5 g
x = (20)   = 40 mL
1
 
0.5 
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
Example Problem III:
If you have 100 mL of snow, what
volume of water do you have? (You must
first find out what mass of snow you
have and then convert that to volume of
water.)
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
Step 1: Proportional Analsysis
0.5 g
=
1 mL
x g
100 mL
x = (0.5)(100 mL) = 50 grams
Step 2: Proportional Analsysis
1g
1 mL
=
50 g
x mL
x = (1)(50) = 50 mL
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
Step 1: Dimensional Analysis
100 mL
0.5 g
= 50 grams
1 mL
Step 2: Dimensional Analysis
50 mL
1g
= 50 mL
1 mL
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Check-In
• You have equal masses of snow and
rain. Which has a greater volume?
Explain your thinking.
• What is the mass of 14 mL of
rainwater?
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Wrap-Up
• Density is a measure of the mass of
a substance per unit of volume.
• If the ratio between two quantities is
constant then a graph of these two
quantities will be a line that passes
through the origin.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
• Water can have different densities
depending on whether it is snow, ice or
liquid (rain).
• When a substance changes phase
(from solid to liquid to gas) it changes
density.
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Weather Unit – Investigation I
Lesson 4:
It’s Sublime
ChemCatalyst
• Describe the differences between the
two.
• Why do you think one is called “dry”
ice?
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
The Big Question
• How different are the densities of a
solid and a gas of the same
substance?
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
You will be able to:
• Understand the change in density as a
substance goes from a solid to a gas.
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Activity
Materials:
5-20 grams of dry ice per team of students
Styrofoam cooler or ice chest
Scale
Medium plastic garbage bags—five-gallon
size
Twist tie
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
2 Oven mitts
Five gallon bucket or other cylindrical
receptacle (Note: 5 gallons ~19 liters)
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
Copy this table into your notebook.
Mass of CO2(s)
(g)
Volume of CO2 solid
(mL)
Volume of CO2 gas
(mL)
Note: This table is different than the one
in your book.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Safety Note: Use gloves – dry ice can
cause frostbite.
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Making Sense
• If you sublime 1 mL of CO2 (s), what
volume will the gas occupy?
• How many times larger than the
volume of the solid carbon dioxide is
the volume of the carbon dioxide gas?
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
Mass vs. Volume of Gaseous Carbon Dioxide
100
CO2 (s)
1.56 g/mL
Mass (g)
80
60
40
CO2 (g)
0.0019 g/mL
20
0
0
20
40
60
Volume (mL)
80
100
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)

Solid CO2
Gas Model A
Gas Model B
Gas Model C
Which model is correct?
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
How do we find the volume of the solid?
• D = m/V or V = m/D
• We know
m = g (from our data table)
•
D = 1.56 g/mL (from graph)
• So do the math . . .
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Sample Data
Mass of CO2(s)
(g)
Volume of CO2 solid
(mL)
Volume of CO2 gas
(mL)
5.0 g
2500 mL
8.2 g
4200 mL
12.7 g
6500 mL
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Wrap-Up
• Sublimation occurs when a substance
goes directly from a solid phase to a
gas phase (or vice versa).
• The density of a gas is about 1/1000
the density of the same solid.
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Weather Unit – Investigation I
Lesson 5:
Water World
ChemCatalyst
Suppose a quantity of rainwater
occupies a volume of 1 mL.
• What volume do you think the
rainwater occupies as water vapor?
Explain your thinking.
• When water changes phase what other
changes take place? Name at least
three changes.
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
The Big Question
• How are volume, density, and phase of
water related to weather?
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
You will be able to:
• Explain the increase in volume as
1 mL of water goes from a liquid to a
gas.
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Activity
Purpose: The purpose of this lesson is
to explore how phase changes are
related to volume changes, density
changes, and the water cycle in
general.
Part I: Comparing densities
Densities of various substances have
been labeled in the Density Landscape
handout.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
snow
H2O (s), 0.92
g/mL
water vapor
subliming from
snow, H2O (g),
0.0006 g/mL
helium blimp
0.00016 g/mL
cloud
air at 3000 m above
sea level
0.00091 g/mL
molten lava
2.2 g/mL
rain
H2O (l),
1.00 g/mL
solid lava
2.4 g/mL
mine shaft leading
to gold, Au (s),
19.32 g/mL
ice
H2O (s),
0.92 g/mL
lake
H2O (l),
1.00 g/mL
oil
0.92 g/mL
pine log
0.5 g/mL
air at sea level
0.0012 g/mL
happy
bear
iron anchor
Fe (s), 7.87 g/mL
fire extinguisher
carbon dioxide
aluminum cooler
dry ice to
containing liquid carbon
subliming from dry ice,
Al (s),
preserve fish
dioxide
2.70 g/mL
CO2 (s),
1.56 CO2 (g), 0.0019 g/mL
CO2 (g), 1.2 g/mL
g/mL
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
Part II: Average rainfall
A map of average rainfall in the United
States (in inches/yr) is shown below.
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Making Sense
• How are volume, density, and phase of
water related to the weather?
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Notes
Phase Change
• Drives the water cycle and weather
• Results in changes in volume and
density
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Check-In
As water moves around the water cycle,
its volume changes.
• If rainwater occupies a volume of 1
mL, what volume will it occupy when it
forms water vapor?
• What is the main reason for the
increase in volume during this phase
change?
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
Wrap-Up
• The density of a substance in the solid phase
is nearly the same as its density in the liquid
phase.
• The density of a substance in the gaseous
phase will be much lower than its densities in
the liquid and solid phases. Gases are about
1000 times less dense than liquids and solids.
(cont.)
© 2004 Key Curriculum Press.
Unit 3 • Investigation I
(cont.)
• The density of a substance has a great
deal to do with where that substance
can be found on the planet in
relationship to other substances.
© 2004 Key Curriculum Press.
Unit 3 • Investigation I