1. Melting Point and Freezing
Point of Naphthalene
SSI 3013 Information and Communication
Technology in Science
Name: Matric No.:
Chan Su Fang D 20101037450
Chang Pei Xian D 20101037455
Rochelle Tang Nga Ning D 20101037537
Group :A
Lecturer : En. Azmi Ibrahim
2. Data Logging
• Definition:
Is the measurement and recording of
physical or electrical parameters over
a period of time.
3. Components in Data Logger
1. Computer
2. Sensor
• Digital sensor
• Analogue sensor
3. Interface
4. Data logging software
4. Engage, Empower & Enhance
• Engage
–Involve the students in the activity
(set induction)
• Empower
–Give the students a sense of confidence or
self-esteem in term of education
(construct scientific ideas or concept)
• Enhance
–Increase the degree of details for the
concept
(guide students in reflecting their own ideas
related to the daily life)
5. Engage
What caused the changes in
the state of matter?
When a solid is heated
gradually, what will be
happened to the particles in
the solid?
When a liquid is cooled,
what will be happened to the
particles in the liquid?
6. Engage
When a solid is heated
gradually, what will be
happened to the particles in
the solid?
When a liquid is cooled,
what will be happened to the
particles in the liquid?
7. Engage
How to determine the
melting and freezing
point of Naphthalene?
8. Empower
Procedure
Figure 1: Heating of Naphthalene
Figure 1: Heating of Naphthalene
9. Empower
1. The apparatus is set up as shown in Figure 1.
2. The temperature probe (sensor) is connected
to the correct port on the interface. The
interface is then connected to the computer.
The powers to the interface and to the
computer are switched on.
3. A computer file is opened to record and
display the results as a graph of temperature
against time.
10. Empower
5. The program recording conditions is set to:
a) Recording time from 60 ºC until 90 ºC for
temperature of naphthalene
6. The naphthalene is placed in a boiling tube to
about one third of the depth of the tube.
7. The boiling tube is placed in a beaker under
Bunsen burner until all the naphthalene has
liquefied.
8. The data is recorded.
11. Empower
Result
Table 1: Heating of Naphthalene
13. Empower
Discussion
1. What are the states of naphthalene at Point A, from Point B
to C, and at Point D?
2. What is the melting point of naphthalene?
3. Why there is an increase from Point A to B and also from
Point C to D?
4. Why the temperatures from Point B to C remain constant?
14. Empower
1. At Point A, naphthalene exists as solid.
From Point B to C, naphthalene exists as solid and liquid.
At Point D, naphthalene exists as liquid.
2. The melting point of naphthalene is 80.0 C.
3. There is an increase from Point A to B and also from Point C
to D because when the matter is heated, heat energy is
absorbed. The particles gain more energy and vibrate faster.
4. The temperatures from Point B to C remain constant the heat
energy absorbed by the particles was used to overcome the
forces between the particles so that the solid can turn into
liquid.
16. Empower
1. The boiling tube is removed from the beaker.
2. The tube is clamped upright using a retort
stand.
3. The temperature probe (sensor) is placed in
the liquid naphthalene as shown in Figure 2.
4. The program recording conditions is set to
a) Recording time- until the temperature falls to
about 60 C.
17. Empower
5. Recording time- until the temperature falls to
about 60 C.
6. The data is recorded.
7. When the naphthalene has solidified, the
recording is stopped.
8. The boiling tube is removed from the clamp
and placed back into hot water. When the
naphthalene has liquefied, the temperature
probe is removed and it is rinsed with water.
18. Empower
Result
Table 2: Cooling of Naphthalene
20. Empower
Discussion
1. What are the states of naphthalene at Point E, from Point F
to G, and at Point H?
2. What is the freezing point of naphthalene?
3. Why there is an increase from Point E to F and also from
Point G to H?
4. Why the temperatures from Point F to G remain constant?
21. Empower
1. At Point E, naphthalene exists as liquid.
From Point F to G, naphthalene exists as liquid and solid.
At Point H, naphthalene exists as solid.
2. The freezing point of naphthalene is 80.0 C.
3. There is an increase from Point E to F and also from Point G to
H because when the matter is cooled, heat energy is released.
The particles lose their kinetic energy and vibrate slower.
4. The temperatures from Point F to G remain constant because
the heat loss to the surroundings is exactly balanced by the heat
energy liberated as the particles attract one another to form a
solid.
22. Enhance
Due to the unique characteristic of naphthalene,
with same melting and freezing points (80 C),
the mothball wouldn’t melt in room temperature.
23. Enhance
However, the
mothball is able to
sublime at room
temperature by the
way its melting point
is 80 C.
Explain how
naphthalene can be
melt and sublime.
24. Conclusion
Nowadays, the fast growing technology has
influences the direction of learning process
especially in science laboratory classes. We as a
future Science teacher should be able to
implement data logger in laboratory class. The
technology that available such as the data logger,
makes practical work becomes more efficient as
students do not have to spend more time to set up
the apparatus and recording the data.
