Chemistry- Assignment Unit 2: Practical Scientific Procedures and Techniques
EVALUATING THE ACCURACY OF THE COOLING CURVE EXPERIMENT
Cooling curve- The cooling curve is a line graph that depicts the transition of matter from one phase
to another, typically from a gas to a solid or from a liquid to a solid.
Aims
To study the cooling curve of stearic acid and its rate of cooling
To study the cooling curve of paraffin wax
To find the accuracy of the thermometers
CALIBRATION OF THERMOMETERS
Results From Calibration of Liquid Thermometer in Iced Water
Temperature
1st test 0.7
2nd test 1
3rd test 3
Average 1.6
Results From Calibration of Liquid Thermometer in Boiling Water
Temperature
1st test 94
2nd test 85
3rd test 78
Average 85.7
Results From Calibration of Digital Thermometer in Iced Water
Temperature
1st test 1.1
2nd test 1.7
3rd test 2.0
Average 1.6
, Results From Calibration of Digital Thermometer in Boiling Water
Temperature
1st test 95.5
2nd test 88.8
3rd test 83.9
Average 89.4
Equipment
Digital thermometer
Liquid thermometer
200ml beakers
Ice
Boiling water
Digital timer
Risk Assessment
The boiling water posed a risk of burns. This was avoided by wearing lab coats and exercising
caution when using hot water.
If any burns did occur during the experiment, the injured person would have poured water
on the affected area and emergency care would be given to the injured experimenter.
There was also a possibility of cuts if the glass equipment managed to break, which has been
mitigated by using lab coats (to protect the outerwear) and googles (to protect the
investigators eyes).
If there’s any breaks, the mentor guiding was immediately notified to avoid the risk of cuts.
If cuts had took place during the practical, the injured investigator would have received
medical attention immediately.
Method
Using Ice
1. A beaker was filled with ice cubes, then water was placed in the beaker.
2. The water was stirred and was then left to sit for 30 minutes.
3. The ice was stirred again, and then thermometers (digital and liquid) was placed.
EVALUATING THE ACCURACY OF THE COOLING CURVE EXPERIMENT
Cooling curve- The cooling curve is a line graph that depicts the transition of matter from one phase
to another, typically from a gas to a solid or from a liquid to a solid.
Aims
To study the cooling curve of stearic acid and its rate of cooling
To study the cooling curve of paraffin wax
To find the accuracy of the thermometers
CALIBRATION OF THERMOMETERS
Results From Calibration of Liquid Thermometer in Iced Water
Temperature
1st test 0.7
2nd test 1
3rd test 3
Average 1.6
Results From Calibration of Liquid Thermometer in Boiling Water
Temperature
1st test 94
2nd test 85
3rd test 78
Average 85.7
Results From Calibration of Digital Thermometer in Iced Water
Temperature
1st test 1.1
2nd test 1.7
3rd test 2.0
Average 1.6
, Results From Calibration of Digital Thermometer in Boiling Water
Temperature
1st test 95.5
2nd test 88.8
3rd test 83.9
Average 89.4
Equipment
Digital thermometer
Liquid thermometer
200ml beakers
Ice
Boiling water
Digital timer
Risk Assessment
The boiling water posed a risk of burns. This was avoided by wearing lab coats and exercising
caution when using hot water.
If any burns did occur during the experiment, the injured person would have poured water
on the affected area and emergency care would be given to the injured experimenter.
There was also a possibility of cuts if the glass equipment managed to break, which has been
mitigated by using lab coats (to protect the outerwear) and googles (to protect the
investigators eyes).
If there’s any breaks, the mentor guiding was immediately notified to avoid the risk of cuts.
If cuts had took place during the practical, the injured investigator would have received
medical attention immediately.
Method
Using Ice
1. A beaker was filled with ice cubes, then water was placed in the beaker.
2. The water was stirred and was then left to sit for 30 minutes.
3. The ice was stirred again, and then thermometers (digital and liquid) was placed.
