IAN AGUSTIN B. CARDAÑO
BSED SCIENCE 2B
MIDTERM EXAM IN THERMODYNAMICS (LAB)
LABORATORY ACTIVITY
THERMAL EXPANSION
I.
OVERVIEW
Thermal expansion is the tendency of matter to change its shape, area, volume
and density in response to a change in temperature. Temperature is a monotonic function of the
average molecular kinetic energy of a substance. When a substance is heated, molecules begin
to vibrate and move more, usually creating more distance between themselves. Substances
which contract with increasing temperature are unusual, and only occur within limited
temperature ranges (see examples below). The relative expansion (also called strain) divided
by the change in temperature is called the material's coefficient of linear thermal
expansion and generally varies with temperature. As energy in particles increases, they start
moving faster and faster, weakening the intermolecular forces between them and therefore
expanding the substance. To understand the concept of thermal expansion, consider first what
the temperature of a material signifies. The temperature of a material is associated with the
random motion of the material’s molecules; the material’s temperature is essentially a measure
of the kinetic energy of these moving molecules. Now, the faster the molecules move, the
greater the temperature of the material, and the greater is the space taken up by these
molecules. Thus, when heat is supplied to material, its temperature increases coupled with an
increase in the dimensions of the material, which is the thermal expansion of the material.
II.
OBJECTIVES
• explain why matter expands when heated
• understand why temperature is a factor to thermal expansion
• conduct an experiment related to how matter changes in response to temperature
• manifest the application of thermal expansion
III.
MATERIALS
ACTIVITY A
1. Alcohol Lamp (or bunsen burner w/natural gas) 6. Lighter or matches
2. Tripod Stand
7. Thermometer
3. 2 soda can container (325 mL)
4. Tap Water
5. Timer
ACTIVITY B (Linear Expansion)
1. 30 cm Steel bar (construction reinforcement bars or rebars)
2. 30 centimeters Aluminum steel
3. Timer
(This activity must be done under the sun)
IAN AGUSTIN B. CARDAÑO
IV.
BSED SCIENCE 2B
MIDTERM EXAM IN THERMODYNAMICS (LAB)
PROCEDURES
ACTIVITY A
• Prepare the stand and alcohol lamp for boiling of water in soda can
• Pour 320 mL of tap water in the soda can
• Record your initial observation
• Lit the alcohol lamp for boiling
• Set time for (no of minutes) and observe the water as it response to rise of
temperature in a span of time.
• After boiling record the final observation.
•Compare and Contrast
ACTIVITY B
• Place the two 30 cm materials (steel bar and aluminum steel) outside (w/natural light
from the sun).
• Determine the distinction of two materials (in terms of linear coefficient)
• Measure the initial temperature of an object and the surrounding temperature
• Set time and observe changes
• Record your data
V.
ANALYSIS
ACTIVITY A (TABLE)
INITIAL OBSERVATION
FINAL OBSERVATION
SODA CAN A
(BOILED)
Temperature 28°C
Water at still
SODA CAN B
(NOT HEATED)
Temperature 28°C
Water at still
Temperature 100°C
Water rises
Forms bubbles
Spills out of the can
Produces steam
Temperature 29°C
Water did not boil due to no
influence of heat
SODA CAN A.
∆T = Tf – Ti
= 100°C – 28°C
∆T = 72°C
SODA CAN B
∆T = Tf – Ti
= 29°C – 28°C
∆T = 1°C
IAN AGUSTIN B. CARDAÑO
BSED SCIENCE 2B
MIDTERM EXAM IN THERMODYNAMICS (LAB)
GRAPH
72°C
28°C
CAN A
1°
C
28°C
CAN B
INITIAL TEMPERATURE
FINAL TEMPERATURE
OBSERVATION
When water is heated it expands, when mercury is placed into the boiling water, the red
mercury in thermometer rises. Water expands when boiling because there is an increase in
temperature caused the water molecules to gain energy and move more rapidly which resulted
in water molecules that are farther apart and an increase in water volume.
Mercury contracts and expands. Mercury’s response to temperature change is fast.
IAN AGUSTIN B. CARDAÑO
BSED SCIENCE 2B
MIDTERM EXAM IN THERMODYNAMICS (LAB)
ACTIVITY B
TABLE: COMPARISON OF LINEAR EXPANSION
DATA:
30 cm (0.30m).
Final Temperature: NOON October 25, 2023 = 31°C
ALUMINUM: Final Temperature: 31°C.
Initial Temperature: 20°C
STEEL: Final Temperature: 31°C.
Initial Temperature: 26°C
COEFFICIENT OF LINEAR EXPANSION
ALUMINUM: 25 x 10(-6)
STEEL: 11 x 10(-6)
MATERIAL
INITIAL LENGTH
STEEL
ALUMINUM
30 cm (0.30m)
30 cm (0.30m)
CHANGE IN LENGTH AFTER 15 MINUTES
Al = 30.00825 cm
Steel = 30.00165 cm
CHANGE IN LENGTH DUE
TO CHANGE IN
TEMPERATURE
1.6 x 10 (-5) m
8.2 x 10 (-5) m
IAN AGUSTIN B. CARDAÑO
BSED SCIENCE 2B
MIDTERM EXAM IN THERMODYNAMICS (LAB)
OBSERVATION
Aluminum extends in length more than the steel bar. At different initial temperatures and
similar final temperature measured during noontime, thermal expansion was observed in
a span of short time. This means that an equal temperature change will produce twice as much
change in the length of a bar of aluminum as for a bar of steel. Thus, aluminum expands more than
steel bar.
LINEAR EXPANSION OF ALUMINUM
BAR AND REBARS
ALUMINUM
STEEL
VI. CONCLUSION
Thermal Expansion is the phenomenon observed in solids, liquid, and gases. In this
phenomena an object or body expands on the application of heat (temperature). The change
in temperature of a matter is mainly caused by heat and by direct contact and constant
response to the object, it expands which causes thermal expansion. A change in length due to
change in temperature is dependent upon the coefficient of an object response to heat.
Therefore, temperature is the monotonic function of thermal expansion. And, thermal
expansion occurs when an object expands or get larger due to an increase in its temperature.
IAN AGUSTIN B. CARDAÑO
BSED SCIENCE 2B
MIDTERM EXAM IN THERMODYNAMICS (LAB)
VII REFERENCES
https://study.com/academy/lesson/thermal-expansion-definition-equation-examples.html
https://en.m.wikipedia.org/wiki/Thermal_expansion
https://www.scientificamerican.com/article/curl-metals-with-heat/
https://www.sciencedirect.com/topics/chemistry/thermal-expansion
IMAGES
SOURCE: www.googleimages.com
SUBJECT: THERMODYNAMICS