Unit: 2 Practical Scientific Procedures and Techniques
Cooling
Calorimetry
Introduction
Calorimetry is an experiment where the temperature of different substances is accurately measured
and recorded, while cooling down as they lose heat energy to their surroundings, causing the
temperature to fall. The different temperatures of the substance that would be recorded while
cooling down, would be used to plot a graph against time taken to discuss the cooling rate. In this
experiment, the aim is to precisely measure the time taken and temperature for stearic acid and
paraffin wax to cool down until room temperature would be reached. Consequently, using the
discovered values, a graph would be plotted and then analysed correctly and skilfully.
Calibration
Calibration is a process that ensures pieces of equipment used for measuring are portraying a
precise measurement. This is a very important procedure because if the equipment is displaying
inaccurate values, it can make the whole experiment erroneous and imprecise. Additionally, there
are many different methods that can be used to calibrate pieces of equipment such using accurate
masses and by using water.
In the experimentation, there is only 1 piece of equipment that needs to be calibrated and that is the
thermometer, which would be done twice as the temperature will be calculated for 2 substances.
Thermometer
The calibration of the thermometer is performed using hot water and to find out whether an
electronic thermometer is faster at showing an accurate temperature or a liquid-filled thermometer.
Equipment List
▪ Electronic thermometer – Being calibrated to see if it is faster compared to the liquid-filled
thermometer
▪ Liquid-filled thermometer – Being calibrated to see if it is faster compared to the electrical
thermometer
▪ 2 × beaker – Used as containers for the ice water and the hot water
▪ Water
▪ Ice All placed in a beaker to test the thermometers
▪ Salt
▪ Kettle with water – Placed in another beaker to test the thermometers
Method
1. Firstly, some ice, water and salt were placed in a beaker and the electrical thermometer was
placed inside until it reached 0 °C or below
2. While the thermometer was inside the beaker and was reaching the 0 °C or below, some
boiling water from the kettle was poured inside the other beaker.
3. As soon as the water was poured into the beaker, the thermometer from the ice water
beaker was moved into the beaker with the hot water.
4. A timer was turned on as soon the thermometer was moved into the beaker with the boiling
water to observe how much time it takes the thermometer to move from 0 °C or below to
, 100°C or below, which was to compare the time later once the liquid-filled thermometer
would also be calibrated.
5. Once the time was recorded, the boiling water was poured down the sink slowly as the
calibration process was going to be repeated but by the time the other thermometer
reached 0 °C or below, the water may cool down making the process inaccurate.
6. The liquid-filled thermometer was placed inside the beaker with the ice water, until it
reached 0 °C or below.
7. While the thermometer was inside the beaker and was reaching the 0 °C or below, some
boiling water from the kettle was poured inside the other beaker again because the
previously poured water was poured down the sink as it would cool down by the time this
step would be reached.
8. As soon as the water was poured into the beaker, the thermometer from the ice water
beaker was moved into the beaker with the hot water.
9. A timer was turned on as soon the thermometer was moved into the beaker with the boiling
water to observe how much time it takes the thermometer to move from 0 °C or below to
100°C or below, which was to compare the time later with the electrical thermometer.
10. Using the 2 values that written down, the more precise thermometer was going to be picked
to be used when the temperature of the substances would be utilized.
Paraffin Wax
The temperature of the paraffin wax was accurately measured using one of the calibrated
thermometers as it was cooling down, which was caused by the loss of heat energy to its
surrounding. The values that were recorded were then used to plot a graph of temperature against
time to discover the cooling rate of the paraffin wax as well as the melting point by drawing a series
of tangents.
Equipment List
▪ Resting rack – This is where the boiling tube will be placed to avoid it from rolling off the
table but also to avoid it from burning hands as it will be warm
▪ Boiling tube – Acts like a container for the paraffin wax
▪ Thermometer (that was selected as the better thermometer when being calibrated
previously) – To measure the temperature of the paraffin wax while it cools down
▪ Timer – To measure how much time it takes for the temperature of the paraffin wax to fall
by 1 °C
▪ 5g of Paraffin wax – The substance whose temperature will be measured as it cools down
▪ Water bath – Used to completely melt the paraffin wax while it is in the boiling tube
Method
1. Firstly, 5g of paraffin wax was measured using a weighing scale and placed into a boiling
tube. Only 5g were used because using too much substance would affect the cooling, which
would ultimately cause the melting point that was found out to be inaccurate.
2. The boiling tube was sealed with a rubber bung and placed inside a water bath. The boiling
tube was sealed with a rubber bung while the substances were being melted in a water bath
to deter the air from affecting the temperature of the substances. Additionally, boiling tube
was utilized as the container for the paraffin wax because it can also affect the rate of
cooling. This is because, for example, if the paraffin wax would be cooled in a tray, it would
have a faster cooling rate whereas if placed in a mug, only the top will be cooled down
faster, and the bottom would cool down very slowly. Therefore, the boiling tube was the
container used so that the cooling process would be uniformly completed.
Cooling
Calorimetry
Introduction
Calorimetry is an experiment where the temperature of different substances is accurately measured
and recorded, while cooling down as they lose heat energy to their surroundings, causing the
temperature to fall. The different temperatures of the substance that would be recorded while
cooling down, would be used to plot a graph against time taken to discuss the cooling rate. In this
experiment, the aim is to precisely measure the time taken and temperature for stearic acid and
paraffin wax to cool down until room temperature would be reached. Consequently, using the
discovered values, a graph would be plotted and then analysed correctly and skilfully.
Calibration
Calibration is a process that ensures pieces of equipment used for measuring are portraying a
precise measurement. This is a very important procedure because if the equipment is displaying
inaccurate values, it can make the whole experiment erroneous and imprecise. Additionally, there
are many different methods that can be used to calibrate pieces of equipment such using accurate
masses and by using water.
In the experimentation, there is only 1 piece of equipment that needs to be calibrated and that is the
thermometer, which would be done twice as the temperature will be calculated for 2 substances.
Thermometer
The calibration of the thermometer is performed using hot water and to find out whether an
electronic thermometer is faster at showing an accurate temperature or a liquid-filled thermometer.
Equipment List
▪ Electronic thermometer – Being calibrated to see if it is faster compared to the liquid-filled
thermometer
▪ Liquid-filled thermometer – Being calibrated to see if it is faster compared to the electrical
thermometer
▪ 2 × beaker – Used as containers for the ice water and the hot water
▪ Water
▪ Ice All placed in a beaker to test the thermometers
▪ Salt
▪ Kettle with water – Placed in another beaker to test the thermometers
Method
1. Firstly, some ice, water and salt were placed in a beaker and the electrical thermometer was
placed inside until it reached 0 °C or below
2. While the thermometer was inside the beaker and was reaching the 0 °C or below, some
boiling water from the kettle was poured inside the other beaker.
3. As soon as the water was poured into the beaker, the thermometer from the ice water
beaker was moved into the beaker with the hot water.
4. A timer was turned on as soon the thermometer was moved into the beaker with the boiling
water to observe how much time it takes the thermometer to move from 0 °C or below to
, 100°C or below, which was to compare the time later once the liquid-filled thermometer
would also be calibrated.
5. Once the time was recorded, the boiling water was poured down the sink slowly as the
calibration process was going to be repeated but by the time the other thermometer
reached 0 °C or below, the water may cool down making the process inaccurate.
6. The liquid-filled thermometer was placed inside the beaker with the ice water, until it
reached 0 °C or below.
7. While the thermometer was inside the beaker and was reaching the 0 °C or below, some
boiling water from the kettle was poured inside the other beaker again because the
previously poured water was poured down the sink as it would cool down by the time this
step would be reached.
8. As soon as the water was poured into the beaker, the thermometer from the ice water
beaker was moved into the beaker with the hot water.
9. A timer was turned on as soon the thermometer was moved into the beaker with the boiling
water to observe how much time it takes the thermometer to move from 0 °C or below to
100°C or below, which was to compare the time later with the electrical thermometer.
10. Using the 2 values that written down, the more precise thermometer was going to be picked
to be used when the temperature of the substances would be utilized.
Paraffin Wax
The temperature of the paraffin wax was accurately measured using one of the calibrated
thermometers as it was cooling down, which was caused by the loss of heat energy to its
surrounding. The values that were recorded were then used to plot a graph of temperature against
time to discover the cooling rate of the paraffin wax as well as the melting point by drawing a series
of tangents.
Equipment List
▪ Resting rack – This is where the boiling tube will be placed to avoid it from rolling off the
table but also to avoid it from burning hands as it will be warm
▪ Boiling tube – Acts like a container for the paraffin wax
▪ Thermometer (that was selected as the better thermometer when being calibrated
previously) – To measure the temperature of the paraffin wax while it cools down
▪ Timer – To measure how much time it takes for the temperature of the paraffin wax to fall
by 1 °C
▪ 5g of Paraffin wax – The substance whose temperature will be measured as it cools down
▪ Water bath – Used to completely melt the paraffin wax while it is in the boiling tube
Method
1. Firstly, 5g of paraffin wax was measured using a weighing scale and placed into a boiling
tube. Only 5g were used because using too much substance would affect the cooling, which
would ultimately cause the melting point that was found out to be inaccurate.
2. The boiling tube was sealed with a rubber bung and placed inside a water bath. The boiling
tube was sealed with a rubber bung while the substances were being melted in a water bath
to deter the air from affecting the temperature of the substances. Additionally, boiling tube
was utilized as the container for the paraffin wax because it can also affect the rate of
cooling. This is because, for example, if the paraffin wax would be cooled in a tray, it would
have a faster cooling rate whereas if placed in a mug, only the top will be cooled down
faster, and the bottom would cool down very slowly. Therefore, the boiling tube was the
container used so that the cooling process would be uniformly completed.
