Unit 2: Assignment 2: Melting and boiling point
In this assignment the cooling curve will be used to determine the rate of cooling substances,
obtain data using different equipment to construct cooling curves, analyse the rate of the cooling
of substances from the recorded data using the cooling curves to draw conclusions and evaluate
the accuracy of practical work in calorimetry in relation to the analysis of the cooling curves.
Aim
Be able to calibrate different types of thermometers and as well be able to determine the melting
point of the stearic acid and paraffin wax to find the cooling point using the cooling curve graphs.
Calibration of the thermometers
The calibration of the mercury and alcohol based thermometers was done using cold and hot water.
The method was to start with filling a large beaker (250 cm 3) with crushed ice and topped it up with
a small account of tap water. The crushed ice was then stirred with glass rod then left it to stand for
around 2-3 minutes. The thermometer was then placed into the beaker and then I took the reading
every minute for 11 min and recorded the results on a suitable table which is shown below.
Then the calibration of the thermometers was done with hot water where the water inside the
beaker was boiled which indicates that the temperature has reached 100 °C. The thermometer was
then placed inside the boiling water and the readings was taken every minute for 11 min and the
results was recorded on the table below.
Time in minutes Mercury Mercury based Alcohol Alcohol Digital Digital
temp°C (hot based based based based
Based
H2O) temp. °C temp. °C temp. °C
Temp.
Temp.
(cold H2O) (hot H2O) Hot H2O °C
°C
Cold
(cold
H2O
H2O)
1 3.0 87 3.0 87 97 2.3
2 2.5 85 3.0 83 91.5 1.3
3 2.5 80 3.0 79 85.7 1.2
4 1.0 76 1.5 75 82.6 0.9
5 1.0 74 1.5 72 79.2 0.9
6 1.0 73 1.5 70 76.2 0.7
7 1.0 69 1.0 67 74.2 0.7
8 1.0 67 1.0 65 73.3 0.6
9 1.0 65 1.0 63 71.2 0.6
10 1.0 64 1.0 59 68.6 0.5
11 1.0 63 0.5 59 67.4 0.5
,Initial 20 89 23.5 88 98 23
Temperature
(°C)
Cooling curve for water in Styrofoam cup
Aim
Be able to construct the cooling curve of water in Styrofoam cup
Introduction
In this experiment the calorimeter technique will be used to measure the cooling curve of solvents.
The calorimeter is basically a container either as glass beaker or polystyrene cup that can be used
with a thermometer to measure the temperature during a reaction in which heat is exchanged with
the immediate outer environment. The calorimeter has a general uses such as monitoring
endothermic or exothermic reactions, monitoring change of physical phases such as freezing (liquid
turns to solid) and melting (solid turns to liquid) and finally its use in measuring specific heat
capacity. So simply said the process of measurement of the heat transferred is called calorimetry.
There are two different types of thermometers, liquid - filled such as alcohol based thermometer,
mercury based thermometer and there is the electronic such as thermistor, resistance one,
thermocouple, rotary and infra-red. Each one of the thermometers has its own principle of
operation and main applications.
Diagram 1: Digital thermometer Diagram 2: Alcohol based thermometer
https://www.amazon.co.uk/Thermometers-Kitchen-Home/b?ie=UTF8&node=10707731
http://www.allafrance.com/products/precision-alla-france-r-thermometers-red-liquid-c-11_17.html
Apparatus
● Retort stand and clamp
● Alcohol based thermometer
● Wood lid
● Styrofoam cup
● Bunsen Burner
● Tripod
, ● Heat resistant mat
● Beaker (250 cm3)
● Boiling water (solvent)
● Gauze
● Stop clock
http://schoolworkhelper.net/temperature-of-hot-water-and-cooling-rate-lab/
Diagram 3: Apparatus setup for producing the cooling curve for water
Health and safety
▪ Do not enter a laboratory without any teacher or tutor
▪ Not eating and drinking in a laboratory
▪ No running or playing in the laboratory
▪ Report any injuries to the tutor
▪ Report any damaged equipment to the tutor
▪ Wear proper lab gear such as lab coat, googles and gloves before starting the experiment
▪ Make sure your hair is tied up as Bunsen burner will be used
▪ Handle the glassware very carefully
▪ Read the instructions before starting the experiment
Risk assessment
Equipment / Risk Prevention Treatment
chemical
hazard
Boiling water Burns Wear proper lab gear such lab Wash the burned area with
coat, googles and lab coat plenty of cold water and seek
medical help if the case is very
serious
Bunsen burner Burns Wear proper lab gear such lab Seek medical help and wash the
coat, googles and gloves, follow burned area with plenty of cold
the instructions with great care water
glassware Cut and Wear gloves and proper lab gear Get the first aid and plaster the
In this assignment the cooling curve will be used to determine the rate of cooling substances,
obtain data using different equipment to construct cooling curves, analyse the rate of the cooling
of substances from the recorded data using the cooling curves to draw conclusions and evaluate
the accuracy of practical work in calorimetry in relation to the analysis of the cooling curves.
Aim
Be able to calibrate different types of thermometers and as well be able to determine the melting
point of the stearic acid and paraffin wax to find the cooling point using the cooling curve graphs.
Calibration of the thermometers
The calibration of the mercury and alcohol based thermometers was done using cold and hot water.
The method was to start with filling a large beaker (250 cm 3) with crushed ice and topped it up with
a small account of tap water. The crushed ice was then stirred with glass rod then left it to stand for
around 2-3 minutes. The thermometer was then placed into the beaker and then I took the reading
every minute for 11 min and recorded the results on a suitable table which is shown below.
Then the calibration of the thermometers was done with hot water where the water inside the
beaker was boiled which indicates that the temperature has reached 100 °C. The thermometer was
then placed inside the boiling water and the readings was taken every minute for 11 min and the
results was recorded on the table below.
Time in minutes Mercury Mercury based Alcohol Alcohol Digital Digital
temp°C (hot based based based based
Based
H2O) temp. °C temp. °C temp. °C
Temp.
Temp.
(cold H2O) (hot H2O) Hot H2O °C
°C
Cold
(cold
H2O
H2O)
1 3.0 87 3.0 87 97 2.3
2 2.5 85 3.0 83 91.5 1.3
3 2.5 80 3.0 79 85.7 1.2
4 1.0 76 1.5 75 82.6 0.9
5 1.0 74 1.5 72 79.2 0.9
6 1.0 73 1.5 70 76.2 0.7
7 1.0 69 1.0 67 74.2 0.7
8 1.0 67 1.0 65 73.3 0.6
9 1.0 65 1.0 63 71.2 0.6
10 1.0 64 1.0 59 68.6 0.5
11 1.0 63 0.5 59 67.4 0.5
,Initial 20 89 23.5 88 98 23
Temperature
(°C)
Cooling curve for water in Styrofoam cup
Aim
Be able to construct the cooling curve of water in Styrofoam cup
Introduction
In this experiment the calorimeter technique will be used to measure the cooling curve of solvents.
The calorimeter is basically a container either as glass beaker or polystyrene cup that can be used
with a thermometer to measure the temperature during a reaction in which heat is exchanged with
the immediate outer environment. The calorimeter has a general uses such as monitoring
endothermic or exothermic reactions, monitoring change of physical phases such as freezing (liquid
turns to solid) and melting (solid turns to liquid) and finally its use in measuring specific heat
capacity. So simply said the process of measurement of the heat transferred is called calorimetry.
There are two different types of thermometers, liquid - filled such as alcohol based thermometer,
mercury based thermometer and there is the electronic such as thermistor, resistance one,
thermocouple, rotary and infra-red. Each one of the thermometers has its own principle of
operation and main applications.
Diagram 1: Digital thermometer Diagram 2: Alcohol based thermometer
https://www.amazon.co.uk/Thermometers-Kitchen-Home/b?ie=UTF8&node=10707731
http://www.allafrance.com/products/precision-alla-france-r-thermometers-red-liquid-c-11_17.html
Apparatus
● Retort stand and clamp
● Alcohol based thermometer
● Wood lid
● Styrofoam cup
● Bunsen Burner
● Tripod
, ● Heat resistant mat
● Beaker (250 cm3)
● Boiling water (solvent)
● Gauze
● Stop clock
http://schoolworkhelper.net/temperature-of-hot-water-and-cooling-rate-lab/
Diagram 3: Apparatus setup for producing the cooling curve for water
Health and safety
▪ Do not enter a laboratory without any teacher or tutor
▪ Not eating and drinking in a laboratory
▪ No running or playing in the laboratory
▪ Report any injuries to the tutor
▪ Report any damaged equipment to the tutor
▪ Wear proper lab gear such as lab coat, googles and gloves before starting the experiment
▪ Make sure your hair is tied up as Bunsen burner will be used
▪ Handle the glassware very carefully
▪ Read the instructions before starting the experiment
Risk assessment
Equipment / Risk Prevention Treatment
chemical
hazard
Boiling water Burns Wear proper lab gear such lab Wash the burned area with
coat, googles and lab coat plenty of cold water and seek
medical help if the case is very
serious
Bunsen burner Burns Wear proper lab gear such lab Seek medical help and wash the
coat, googles and gloves, follow burned area with plenty of cold
the instructions with great care water
glassware Cut and Wear gloves and proper lab gear Get the first aid and plaster the
