Unit 2B
Investigating cooling curves
For this experiment I was required to measure the rate of cooling of paraffin wax and steric acid
and used the data gained to make graphs showing the cooling curve for both the substances.
The equipment I used for this were: Stearic acid, Paraffin wax, Bunsen burner, Tripod and
gauze, Liquid and Digital thermometer, 250cm3 Beaker, Clamp stand, Clamp and boss,
Heatproof mat, Stopwatch and Boiling tubes
Health and safety
Goggles & Lab coat were worn for this experiment.
Steric acid (solid) was put into a test tube. The test tube was put into a beaker that was filled
with 200ml of water prior. The water was then heated to 100°C. The test tubes were heated
using the boiling water as it was safer than using a naked flame to heat the test tubes. The
temperature of the steric acid was then measured using a liquid thermometer every 60 seconds
until it got to room temperature. The paraffin wax (solid) was also put in a test tube and heated
until it melted, and the temperature was recorded using a liquid thermometer every 60 seconds
until it reached room temperature.
The liquid thermometer and digital thermometer were calibrated to make sure the readings
were as accurate as possible. They were calibrated by being used to record temperature
change. They were put in ice cold water to see the accuracy at 0°C then I heated the water to
boiling point and checked if the thermometer recorded 100°C accurately. The liquid
thermometer was sometimes 0.5°C above the expected temperature so that amount was
subtracted from the final amount. The digital thermometer was calibrated by holding the ‘CAL’
button to self-calibrate the thermometer. It reads 0 in ice cold water and 100°C in boiling water.
The digital thermometer’s reading kept changing between 0.5c above the expected
temperature to 1c so I used the mean result before it was recorded.
Results
Time (s) Temperature of stearic acid (°C) Temperature of Paraffin Wax (°C)
0 71.6°C 80.1°C
60 65 .5°C 75.2°C
120 60.3°C 66.6°C
180 58.5°C 60.8°C
240 57.1°C 56.4°C
300 55.8°C 54.1°C
360 54.2°C 53.4°C
420 52.6°C 51.2°C
, 480 52.3°C 50.1°C
540 52.4°C 50.2°C
600 52.2°C 50.1°C
660 49.1°C 50.5°C
720 45.2°C 50.7°C
780 40.3°C 58.2°C
840 38.4°C 47.1°C
900 35.1°C 45.0°C
960 30.2°C 42.0°C
1,020 29.7°C 40.1°C
1,080 26.4°C 36.5°C
1,140 24.2°C 32.9°C
1,200 21.6°C 29.4°C
1,260 20.3°C 25.7°C
1,320 20.1°C 20.5°C
Classmates Results
Time (s) Paraffin Wax (C) Stearic Acid (C)
0 80.3°C 71.1°C
60 75.5°C 65.2°C
120 66.4°C 60.1°C
180 60.7°C 58.5°C
240 56.5°C 55.3°C
300 54.4°C 55.2°C
360 53.1°C 52.1°C
420 52.4°C 52.1°C
480 50.4°C 52.2°C
540 50.6°C 52.4°C
600 50.9°C 52.3°C
660 50.8°C 49.9°C
720 50.9°C 45.8°C
780 50.9°C 40.6°C
840 49.6°C 38.9°C
900 48.1°C 35.8°C
960 47.3°C 30.4°C
1,020 45.9°C 29.1°C
Investigating cooling curves
For this experiment I was required to measure the rate of cooling of paraffin wax and steric acid
and used the data gained to make graphs showing the cooling curve for both the substances.
The equipment I used for this were: Stearic acid, Paraffin wax, Bunsen burner, Tripod and
gauze, Liquid and Digital thermometer, 250cm3 Beaker, Clamp stand, Clamp and boss,
Heatproof mat, Stopwatch and Boiling tubes
Health and safety
Goggles & Lab coat were worn for this experiment.
Steric acid (solid) was put into a test tube. The test tube was put into a beaker that was filled
with 200ml of water prior. The water was then heated to 100°C. The test tubes were heated
using the boiling water as it was safer than using a naked flame to heat the test tubes. The
temperature of the steric acid was then measured using a liquid thermometer every 60 seconds
until it got to room temperature. The paraffin wax (solid) was also put in a test tube and heated
until it melted, and the temperature was recorded using a liquid thermometer every 60 seconds
until it reached room temperature.
The liquid thermometer and digital thermometer were calibrated to make sure the readings
were as accurate as possible. They were calibrated by being used to record temperature
change. They were put in ice cold water to see the accuracy at 0°C then I heated the water to
boiling point and checked if the thermometer recorded 100°C accurately. The liquid
thermometer was sometimes 0.5°C above the expected temperature so that amount was
subtracted from the final amount. The digital thermometer was calibrated by holding the ‘CAL’
button to self-calibrate the thermometer. It reads 0 in ice cold water and 100°C in boiling water.
The digital thermometer’s reading kept changing between 0.5c above the expected
temperature to 1c so I used the mean result before it was recorded.
Results
Time (s) Temperature of stearic acid (°C) Temperature of Paraffin Wax (°C)
0 71.6°C 80.1°C
60 65 .5°C 75.2°C
120 60.3°C 66.6°C
180 58.5°C 60.8°C
240 57.1°C 56.4°C
300 55.8°C 54.1°C
360 54.2°C 53.4°C
420 52.6°C 51.2°C
, 480 52.3°C 50.1°C
540 52.4°C 50.2°C
600 52.2°C 50.1°C
660 49.1°C 50.5°C
720 45.2°C 50.7°C
780 40.3°C 58.2°C
840 38.4°C 47.1°C
900 35.1°C 45.0°C
960 30.2°C 42.0°C
1,020 29.7°C 40.1°C
1,080 26.4°C 36.5°C
1,140 24.2°C 32.9°C
1,200 21.6°C 29.4°C
1,260 20.3°C 25.7°C
1,320 20.1°C 20.5°C
Classmates Results
Time (s) Paraffin Wax (C) Stearic Acid (C)
0 80.3°C 71.1°C
60 75.5°C 65.2°C
120 66.4°C 60.1°C
180 60.7°C 58.5°C
240 56.5°C 55.3°C
300 54.4°C 55.2°C
360 53.1°C 52.1°C
420 52.4°C 52.1°C
480 50.4°C 52.2°C
540 50.6°C 52.4°C
600 50.9°C 52.3°C
660 50.8°C 49.9°C
720 50.9°C 45.8°C
780 50.9°C 40.6°C
840 49.6°C 38.9°C
900 48.1°C 35.8°C
960 47.3°C 30.4°C
1,020 45.9°C 29.1°C
