Undertake calorimetry to study cooling curves
Introduction
I am a newly appointed technical assistant at a large chemical plant, Chemcalequip.
For this assignment I will demonstrate my practical procedures and techniques, I will
use calorimetry to do so. Making sure I calibrate all the equipment and that they’re
safely checked to avoid any risks. My skills will be shown throughout the assignment
as my calculations, results, diagrams, and evaluation containing the improvements I
could’ve made during the experiments will be provided.
Aim
Using calorimetry to determine the changes in temperature of cooling curves using
stearin acid and paraffin acid.
Key words:
- Calorimetry: the term used to describe investigations which use a calorimeter
to measure heat transfer in relation to changes in state, phase and chemical
reactions.
- Intermolecular forces: forces of attraction which exist between molecules.
Thermometers
- Liquid-filled thermometer (resolution = 1°C)
- digital thermometer (resolution = 0.1°C)
LEARNER ASSESSMENT SUBMISSION AND DECLARATION
, The functioning of a thermometer is based on the principle that both liquids and solids
have a tendency to expand as their temperature rises. (byjus, n.d.)
Aim
To calibrate two different types of thermometers, to help identify which one is more
accurate, reliable, and easier to use.
Liquid-filled thermometer (Pearson BTEC National, 2016)
- Alcohol in glass: a scientific amount of alcohol is tinted and introduced into a
glass tube under pressurised conditions. As the temperature increases, the
alcohol undergoes expansion with a temperature rise, although it is slow to
respond, and can only be measured up to a maximum of +78°C. In the event of
the glass breaking the alcohol isn’t hazardous to humans. The primary
applications of alcohol in glass thermometers include clinical usage, such as in
hospitals; industrial complexes, schools, and colleges; and domestic use.
- Mercury in glass: a small quantity of mercury is sealed within a glass tube.
The metal exhibits rapid responses to temperature change. These are the two
fundamental designs, a straight tube and another that features a slight bend at
the base to prevent liquid from dropping quickly when removed from the
mouth. Mercury is a toxic and hazardous substance, and interpreting the
readings can be found to be challenging for some people. The principal areas of
application of mercury thermometers are clinical usage, particularly in
hospitals; as well as general industrial use, educational institutions such as
schools and colleges; and practical scientific investigation.
Electronic thermometer (Pearson BTEC National, 2016)
- Thermistor: a thermistor is a semiconductor component that exhibits a
decrease in electrical resistance within a circuit as the temperature increases,
resulting in an increase in current flow. The display of the thermistor may be
digital. Due to their high sensitivity to temperature changes and their ability to
link temperature measurements to electrical circuit resistance, thermistors are
commonly used in switching circuits for heating systems with a ranging
temperature of -250°C to 700°C and fire alarms. In addition, digital
thermometers are frequently used in hospitals for patient care, schools and
working environments in conjunction with “thermometer skin strips”.
- Resistance: a temperature dependent and conductive wire which is integrated
within the thermometer, its electrical resistance increases as its temperature
starts to rise. This type of thermometer is well suited for high temperature
measurements. Although expensive and susceptible to ‘drift’, this type of
thermometer offers an easy-to-read display. Resistance thermometers are
mostly used in industry as it can record high temperatures of up to 1000°C.
- Thermocouple: a thermocouple is formed by joining two wires of different
metals, creating two junctions that produced a potential difference with
changes in temperature. This highly sensitive device is capable of taking short
distance measurements but can be challenging to accurately calibrate the
thermometer. Due to its ability to measure a wide range of temperatures from -
250°C to 1600°C, thermocouples are frequently used in industry as they’re able
to record temperatures up to 1600°C.
- Rotary: the coiled bimetallic strip principle is employed to enable thermal
expansion of the strip when subjected to increased temperatures, resulting in
contact with a calibrated pointer. This principle is characterised by a
straightforward design, which allows general usage such as in greenhouses or
fridge freezers.
- Infrared: this particular type of thermometer works by detecting multiple
wavelengths of infrared electromagnetic radiation, providing a high degree
precision. However, it is limited to measuring surface temperatures and can be
LEARNER ASSESSMENT SUBMISSION AND DECLARATION
Introduction
I am a newly appointed technical assistant at a large chemical plant, Chemcalequip.
For this assignment I will demonstrate my practical procedures and techniques, I will
use calorimetry to do so. Making sure I calibrate all the equipment and that they’re
safely checked to avoid any risks. My skills will be shown throughout the assignment
as my calculations, results, diagrams, and evaluation containing the improvements I
could’ve made during the experiments will be provided.
Aim
Using calorimetry to determine the changes in temperature of cooling curves using
stearin acid and paraffin acid.
Key words:
- Calorimetry: the term used to describe investigations which use a calorimeter
to measure heat transfer in relation to changes in state, phase and chemical
reactions.
- Intermolecular forces: forces of attraction which exist between molecules.
Thermometers
- Liquid-filled thermometer (resolution = 1°C)
- digital thermometer (resolution = 0.1°C)
LEARNER ASSESSMENT SUBMISSION AND DECLARATION
, The functioning of a thermometer is based on the principle that both liquids and solids
have a tendency to expand as their temperature rises. (byjus, n.d.)
Aim
To calibrate two different types of thermometers, to help identify which one is more
accurate, reliable, and easier to use.
Liquid-filled thermometer (Pearson BTEC National, 2016)
- Alcohol in glass: a scientific amount of alcohol is tinted and introduced into a
glass tube under pressurised conditions. As the temperature increases, the
alcohol undergoes expansion with a temperature rise, although it is slow to
respond, and can only be measured up to a maximum of +78°C. In the event of
the glass breaking the alcohol isn’t hazardous to humans. The primary
applications of alcohol in glass thermometers include clinical usage, such as in
hospitals; industrial complexes, schools, and colleges; and domestic use.
- Mercury in glass: a small quantity of mercury is sealed within a glass tube.
The metal exhibits rapid responses to temperature change. These are the two
fundamental designs, a straight tube and another that features a slight bend at
the base to prevent liquid from dropping quickly when removed from the
mouth. Mercury is a toxic and hazardous substance, and interpreting the
readings can be found to be challenging for some people. The principal areas of
application of mercury thermometers are clinical usage, particularly in
hospitals; as well as general industrial use, educational institutions such as
schools and colleges; and practical scientific investigation.
Electronic thermometer (Pearson BTEC National, 2016)
- Thermistor: a thermistor is a semiconductor component that exhibits a
decrease in electrical resistance within a circuit as the temperature increases,
resulting in an increase in current flow. The display of the thermistor may be
digital. Due to their high sensitivity to temperature changes and their ability to
link temperature measurements to electrical circuit resistance, thermistors are
commonly used in switching circuits for heating systems with a ranging
temperature of -250°C to 700°C and fire alarms. In addition, digital
thermometers are frequently used in hospitals for patient care, schools and
working environments in conjunction with “thermometer skin strips”.
- Resistance: a temperature dependent and conductive wire which is integrated
within the thermometer, its electrical resistance increases as its temperature
starts to rise. This type of thermometer is well suited for high temperature
measurements. Although expensive and susceptible to ‘drift’, this type of
thermometer offers an easy-to-read display. Resistance thermometers are
mostly used in industry as it can record high temperatures of up to 1000°C.
- Thermocouple: a thermocouple is formed by joining two wires of different
metals, creating two junctions that produced a potential difference with
changes in temperature. This highly sensitive device is capable of taking short
distance measurements but can be challenging to accurately calibrate the
thermometer. Due to its ability to measure a wide range of temperatures from -
250°C to 1600°C, thermocouples are frequently used in industry as they’re able
to record temperatures up to 1600°C.
- Rotary: the coiled bimetallic strip principle is employed to enable thermal
expansion of the strip when subjected to increased temperatures, resulting in
contact with a calibrated pointer. This principle is characterised by a
straightforward design, which allows general usage such as in greenhouses or
fridge freezers.
- Infrared: this particular type of thermometer works by detecting multiple
wavelengths of infrared electromagnetic radiation, providing a high degree
precision. However, it is limited to measuring surface temperatures and can be
LEARNER ASSESSMENT SUBMISSION AND DECLARATION
