Lab: 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
To use the laboratory set up as a scientific model to demonstrate and explain how clouds are formed
Question
How are clouds formed?
Research: Gather Information
Prelab questions:
1.) Explain how many beakers will be used in the set up and what will be put in each beaker.
2.) How often will temperature be recorded?
3.) Why should the thermometer not touch the bottom or sides of the beaker?
4.) During experiment – observations, how many labels will be placed on the diagram?
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
2 ring clamps with 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. Fill the lower beaker with ice and ½ fill the upper beaker with
ice.
2. Gently heat the ice in the lower beaker. Every three
minutes record the observations and the temperature of the
water in the bottom container in Table 1. Do not touch the
thermometer to the bottom or sides of container.
3. After the ice in the beaker melts and the water begins to
boil, observe the system for several more minutes and
record observations in Table 1.
4. Turn off the heat and let the system completely cool before
cleaning up.
Figure 1. Cloud Apparatus
Data Presentation
Table 1. Temperature Data
Time (minutes)
0
3
6
9
12
15
18
21
24
27
30
Temperature (degrees Celsius)
Observations
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.
Typed Lab Report should include:
1. Pre-lab questions 1-4 answered in complete sentences.
2. Hypothesis written in complete sentences.
3. Data Presentation table.
4. The graph and diagram of lab set-up with the labels from Data Analysis questions.
5. Conclusion questions answered in complete sentences.
6. 5 extra credit points for a computer generated graph!