Models Worksheet – Part 1
essential to life on earth and totally dominates the chemical composition
of all organisms. The characteristics of water regulate a lake's metabolism.
Its unique thermal-density
heat, and freezing point allow the formation of a stratified
environment which controls the chemical and biological properties of
lakes. In Part 1 of this lesson you create summer and winter lake models.
student reading on the Unique Properties of Water.
You need to
create summer and winter lake models based on temperature density stratification.
The following materials are necessary.
- two 5-10 gallon aquaria
- plastic ruler
- red food coloring
- 2 gallon carboy with valve/tygon tube/U-tube assembly
- Pasteur pipettes
- 5 gallons of refrigerated tap water (4-5°C)
- Winter Lake Model
Fill one aquarium
2/3 full with pre-chilled water and add crushed ice to surface. Complete
your Data Collection, Data Management and Analysis for the winter lake
model, and Interpretation of Results question 1 before beginning the summer
Fill the aquarium
2/3 full with pre-chilled water. Using the carboy, tape the U-tube to
a side wall so that the opening is just below the surface.
Slowly add a layer of warm tap water which has been colored with red food
at 2 cm intervals.
at 2 cm intervals.
of the temperature data. Remember to label axes and legends and title
Fill a jar
with hot water (from faucet) and add enough food coloring to make it very
red. Forcefully inject it as deep as possible into the winter lake model
and observe how the water behaves. After you have recorded your observations
for the winter lake model, fill another jar with hot water and add food
coloring to make it very red. Forcefully inject it as deep as possible
into the summer lake model and observe how the water behaves.
1. How does
the water in the winter lake model respond after the hot water is injected?
2. How does
the water in the summer lake model respond after the hot water is injected?
Make up several
jars of different temperature water (ice water, 10-15°C, hot, and hot
plus a tablespoon of salt), and inject each at different depths and
observe the behavior of the water.
to share your results with the class and to explain any discrepancies
in results. Turn your worksheet in to your teacher.
Temperature Density Stratification
in WOW Lake Worksheet – Part 2
Consider what you have learned about
the properties of water from the student reading
and the lake models laboratory exercise. What WOW data might replicate
your lab models?
to use WOW temperature data and the Profile
Plotter to determine if the results from your lab lake models apply
in an actual lake environment.
1. What data might verify your results?
Collect temperature data for Ice Lake
on January 2, 1999 and July 2, 1999.
Create a graph of the temperature profiles
for Ice Lake. Remember to label your axes and legends and title your
the Ice Lake Profile Plotter when does the lake become isothermic?
3. What environmental conditions contributed
to making the lake isothermic?
4. Does your analysis verify your lab
results? If not, what additional data are required?
Be prepared to present your results
to the class. Be prepared to explain any discrepancies in the data.
Turn your worksheet in to your teacher.