Unit 2- Practical Scientific Procedures and Techniques
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Introduction “and aim: In this experiment I used the calorimetry technique to study the
cooling curve of a solid substance” , in this case it would be salol and to find out the
accuracy of the thermometers.
Salol is a chemical substance that is produced by the interactivity between phenol and
salicylic acid. Salol is used as an ultraviolet filter, and it can be used in the making of waxes,
polishes, adhesives, polymers, lacquers, etc.
Obtaining data using different equipment to construct cooling curves and determining
the rate of cooling of substances using cooling curves-
There are liquid filled thermometers and electronic thermometers. The liquid filled
thermometers are alcohol in glass and mercury in glass. I am using an alcohol filled
thermometer because it responds quickly and gives accurate readings and is easy to use
and inexpensive, they are not harmful if they break but they only measure up to 78 ℃ and
are slow to respond. Infra-red thermometers are commonly used in hospitals to determine
the patient’s change in temperature by detecting wavelengths of infrared electromagnetic
radiation but they can only measure surface temperatures and can be affected by other
waves and ambient conditions. I did not use a mercury filled thermometer because it is
harmful if it breaks because mercury is toxic and I did not use an infrared thermometer
because they can only measure surface temperatures and also because they are affected by
ambient conditions including other electromagnetic waves.
PART B.P4
Method of calibration (ice):
1. Put ice and water on a beaker until it fills about ¾ of the beaker.
2. Put the stem of the thermometer in the beaker making sure that the sensor is
underwater and wait a couple of seconds until the reading of the thermometer
stays steady.
3. Adjust the thermometer so it reads 0℃.
4. Mark the position of the thermometer with a permanent marker.
Method of calibration at boiling point:
1. Boil water in a kettle, and pour it on a beaker.
2. Place the thermometer in the boiling water.
3. Make sure that the thermometer does not touch the sides or the base of the
beaker.
4. Read the thermometer for about 30 seconds and the reading should be at
100℃ and mark the position with a marker.
PART B.P3
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, Unit 2 LAB Calorimetry name
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Result table for liquid thermometer in boiling water:
Times the experiment has been done Temperature obtained (°C)
1st time 100°C
2nd time 100°C
3rd time 101°C
4th time 100°C
Average temperature 100.3°C
Result table for liquid thermometer in iced water:
Times the experiment has been done Temperature obtained (°C)
1st time 1°C
2nd time 0°C
3rd time 0°C
4th time 1°C
Average temperature 0.5°C
Result table for digital thermometer in boiling water:
Times the experiment has been done Temperature obtained (°C)
1st time 100°C
2nd time 100°C
3rd time 100°C
4th time 101°C
Average temperature 100.3°C
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