UNIT 2B
Undertake calorimetry to study cooling
curves
Calibration of thermometers
Before any experiment for calorimeter can be undertaken the thermometers
must be calibrated. Calibration is significant since it tests the accuracy of the
equipment being used in calorimetery in order to select the suitable one. In
addition it reduced uncertainty that arises. We calibrated a range of
thermometers ranging from alcohol, mercury and digital thermometers. The
accuracy of all 3 of these thermometers were assessed. Below is a table of
results for each thermometer in accordance to the freezing point and boiling
point.
After assessing the tabulated results I have come to the conclusion that the
best thermometer to use overall would be the digital thermometer since for
, the boiling point the mean recording is 90°C the readings were closer to
100°C which is the boiling point highlighting that in comparison to all the
thermometers the digital thermometer is the most accurate and has less
uncertainty. Therefore it is more suitable to use the digital thermometer for
calibration. The most least suitable thermometer to select would be the
alcohol thermometer since the mean for the boiling point is 79.5 making it
the least closest to the 100°C boiling point. Therefore The alcohol
thermometer is the least accurate and has the most uncertainty and less
accuracy in comparison to all the other thermometer’s therefore I would not
select the alcohol thermometer for this reason.
Cooling curve for stearic acid
The cooling curve is defined as the change of matter from solid, to liquid to
gas in other words it is the rate of cooling. The cooling curve for stearic acid
was determined by undertaking calorimetery and then producing a graph
based on the results obtained. The equipment used to undertake this is
experiment were as follows :
Boiling tube, two 250cm3 beakers, stop clock, mercury thermometer, clamp stand,
clamp and boss, kettle of hot water, heatproof mat, stearic acid
1) Boil the kettle with water and use this to add 150cm3 water into a
beaker
2) Clamp the boiling tube containing stearic acid into the clamp stand and
place the beaker underneath it until the boiling tube is placed into the
hot water
3) Once the stearic acid is visibly turned into a liquid place a
thermometer into the paraffin wax boiling tube. Check to see if the
temperature reading is near boiling point which is around 100°C
4) Once it is around 100°C promptly remove the beaker and start a 51
minute timer.
5) Record the temperature reading for each minute into a results table
with the headings : time (mins), temperature (°C). This will mean you
2
Undertake calorimetry to study cooling
curves
Calibration of thermometers
Before any experiment for calorimeter can be undertaken the thermometers
must be calibrated. Calibration is significant since it tests the accuracy of the
equipment being used in calorimetery in order to select the suitable one. In
addition it reduced uncertainty that arises. We calibrated a range of
thermometers ranging from alcohol, mercury and digital thermometers. The
accuracy of all 3 of these thermometers were assessed. Below is a table of
results for each thermometer in accordance to the freezing point and boiling
point.
After assessing the tabulated results I have come to the conclusion that the
best thermometer to use overall would be the digital thermometer since for
, the boiling point the mean recording is 90°C the readings were closer to
100°C which is the boiling point highlighting that in comparison to all the
thermometers the digital thermometer is the most accurate and has less
uncertainty. Therefore it is more suitable to use the digital thermometer for
calibration. The most least suitable thermometer to select would be the
alcohol thermometer since the mean for the boiling point is 79.5 making it
the least closest to the 100°C boiling point. Therefore The alcohol
thermometer is the least accurate and has the most uncertainty and less
accuracy in comparison to all the other thermometer’s therefore I would not
select the alcohol thermometer for this reason.
Cooling curve for stearic acid
The cooling curve is defined as the change of matter from solid, to liquid to
gas in other words it is the rate of cooling. The cooling curve for stearic acid
was determined by undertaking calorimetery and then producing a graph
based on the results obtained. The equipment used to undertake this is
experiment were as follows :
Boiling tube, two 250cm3 beakers, stop clock, mercury thermometer, clamp stand,
clamp and boss, kettle of hot water, heatproof mat, stearic acid
1) Boil the kettle with water and use this to add 150cm3 water into a
beaker
2) Clamp the boiling tube containing stearic acid into the clamp stand and
place the beaker underneath it until the boiling tube is placed into the
hot water
3) Once the stearic acid is visibly turned into a liquid place a
thermometer into the paraffin wax boiling tube. Check to see if the
temperature reading is near boiling point which is around 100°C
4) Once it is around 100°C promptly remove the beaker and start a 51
minute timer.
5) Record the temperature reading for each minute into a results table
with the headings : time (mins), temperature (°C). This will mean you
2
