L Ab Thermal Energy Changes In Matter (Cloud Lab)

l ab: thermal energy changes in matter (cloud lab) objectives * to identify, explain, and graph thermal energy changes that oc

L ab: Thermal Energy Changes in Matter (Cloud Lab)
Objectives
*
To identify, explain, and graph thermal energy changes that occur
as matter goes through the solid, the liquid, and the gaseous
states
*
T o use the laboratory set up as a scientific model to
demonstrate and explain how clouds are formed
Question
How are clouds formed?
Hypothesize how clouds are formed. (Write the hypothesis in complete
sentences and do not use my, I, we, etc..)
Clouds are formed by…….
Materials
2 beakers
4 ring clamps with 2 wire mesh
Ring stand
Ice
Thermometer and thermometer clamp
Bunsen burner
Stop watch or clock
Lab & graph paper
Procedure

1.
Set up the equipment similar to Figure 1.
2.
F ill the lower beaker about halfway with ice and add about
100 ml of liquid water. Fill the upper beaker with ice.
3.
Gently heat the lower beaker. Every three minutes record
observations for both beakers and the temperature of the water in
the lower beaker in Table 1.
4.
After the ice in the lower beaker melts and the water begins to
boil, record observations for both beakers and record the
temperature of the water in the lower beaker every minute until
the same temperature is recorded 3 times in a row.
5.
Turn off the heat and let the system completely cool before
cleaning up. *CAUTION- HOT objects often look the same as cold
objects.*
Figure 1. Cloud Apparatus
Data Presentation
Table 1. Temperature Data
Time (minutes)
Temperature (degrees Celsius)
Observations
0
3
6
9
12
15
18
21
24
27
30
Data Analysis
1.
Draw a picture of the system used in this lab. Label (1) the state
the water started at in the lower beaker, (2) the state it changed
into the lower beaker, (3) the state above the lower beaker, and
(4) the state on the outside of the upper beaker.
2.
Find the location on the diagram where the water has (A) the
greatest thermal energy and (B) which has the least amount of
thermal energy,
3.
Graph the temperature of water as it goes from solid to a liquid
over time. (time (min) is the independent variable and is placed
on the x-axis, temperature (degrees Celsius) is the dependent
variable and is placed on the y-axis. Be sure to include a title
on the graph and the axes.
Conclusions
1.
Describe the slope of the temperature vs time graph. Be specific
about times and temperatures that were recorded while the water
was melting and boiling and what the slope of the graph looks like
at these areas; as well as, what the slope of the graph looks like
in between these areas.
2.
Was the outside of the top beaker wet or dry at the beginning of
the experiment? Was the outside of the top beaker wet or dry at
the end of the experiment? If it was wet, where did the water come
from?
3.
Use Kinetic Particle Theory to explain the changes that were
graphed while observing the water in the bottom beaker; as well
as, to explain changes that took place on the outside of the top
beaker.
4.
Explain if this lab demonstrates a chemical or a physical change.
5.
Explain how the lab set up can be used as a model to demonstrate
and explain how clouds are formed.
Lab Report should include:
1.
Hypothesis written in complete sentences.
2.
Data Presentation table.
3.
The graph and diagram of lab set-up with the labels from Data
Analysis questions.
4.
Conclusion questions answered in complete sentences.
5.
5 extra credit points for a computer generated graph!