Introduction
This report outlines the results of an experiment conducted to
measure the rate at which paraffin wax cools when placed in a
beaker. The experiment was conducted to determine how quickly
the water would cool in the can, in comparison to cooling in an
open container. The experiment was conducted in a controlled
environment and the data was collected over a period.
Apparatus
- Bunsen Burner
- Tripod
- Heat resistant mat
- Beaker (250 cm3)
- Thermometer
- Boiling water (solvent)
- Gauze
- Stopwatch
- Boiling tube
Calibrate a beaker
1. Fill the beaker to the brim with water.
2. Mark the water level with a marker or pencil.
3. Empty the beaker and measure the water level on the
outside of the beaker.
4. Subtract this measurement from the original water level to
determine the volume of the beaker.
5. Record the beaker’s volume, use this measurement every
time you make measurements in the beaker.
Calibrate the thermometer:
Start by preparing a calibration bath of a known temperature. This
should be done using either a temperature standard that has been
,accurately calibrated or by making a mixture of two known
temperatures.
Place the thermometer into the calibration bath and wait for the
temperature to stabilize.
Record the temperature displayed on the thermometer.
Compare the value to the known temperature of the bath.
If the thermometer does not display the correct temperature,
adjust the calibration setting on the thermometer until the
displayed temperature matches the known temperature.
Repeat steps 2-5 for different temperatures, if desired.
Once the calibration is complete, be sure to label the thermometer
with its new calibration setting.
Calibrate the temperature probe:
1. Begin by cooling the probe to a low temperature.
2. Place the probe in a sealed container with a known temperature
of ice water.
3. Monitor the reading from the probe and adjust the reading until
it matches the ice water temperature.
4. Now heat the probe to a high temperature.
5. Place the probe into a sealed container with a known
temperature of boiling water.
6. Monitor the reading from the probe and adjust the reading until
it matches the boiling water temperature.
,7. Once the probe is calibrated to the two known temperatures, it
should be able to accurately measure temperatures between the
two.
Once the calibration is complete, be sure to label the thermometer
with its new calibration setting.
Calibration is the done to ensure that its predictions are as close as
possible to the true values. This helps us to ensure that our results
are accurate and reliable. Calibration is an important step in data
analysis, as it can help to improve the accuracy of predictions,
reduce bias, and improve model performance. Calibration is
usually done using specialized equipment such as thermometers
and mass balances. This ensures that the results obtained are
precise and consistent. If calibration is not done correctly, the
results obtained may be inaccurate and unreliable. Therefore, it is
important to ensure that the equipment used for calibration is
accurate and up to date. Additionally, any results obtained should
not be altered as this could lead to inaccurate results.
Methodology
Fill the beaker with water at a temperature of 100°C.
A thermometer is placed in the can. This instrument must
have been calibrated previously.
Start the timer.
Measure the initial temperature of the paraffin wax/stearic
acid
Place the paraffin wax/stearic acid in another beaker to start
measuring the cooling rate.
Measure the temperature of the paraffin wax/stearic acid at
regular intervals over the duration of the experiment (every
30 seconds for a period of 30 min).
Record all the temperature readings for the duration of the
experiment.
, Calculate the cooling rate by subtracting the initial
temperature from the final temperature and dividing by the
total time elapsed.
Record the temperature of the water every 30 seconds using
the thermometer and a stopwatch for a period of 30 minutes.
Risks Assesment
The two risks in the experiment are: hot water and glass. To
control these risks, we must stand while doing the experiment,
this is in case the water spills and we need to prevent from falling
to the ground or our laps.
Risk Assessment for Paraffin Wax
1. Fire/Burn Hazard: Paraffin wax is highly flammable and can be
easily ignited. If the wax is spilled, it can easily catch fire and
cause burns.
2. Inhalation Hazard: Paraffin wax fumes can be inhaled, leading
to dizziness, nausea, headaches, and respiratory irritation.
3. Skin Contact Hazard: Prolonged contact with paraffin wax can
cause skin irritation.
4. Eye Contact Hazard: Direct contact with paraffin wax can
cause severe eye irritation and injury.
Control Measures:
1. Store paraffin wax away from sources of heat and flame.
2. Ensure proper ventilation while melting and handling paraffin
wax.
,3. Wear protective clothing, goggles, and face masks while
working with paraffin wax
4. Clean up any spills immediately.
5. Do not eat, drink, or smoke while working with paraffin wax.
Risk Assessment for stearic acid
Stearic acid is a skin and eye irritant and can cause respiratory
irritation and difficulty breathing when inhaled. Inhalation of
concentrated stearic acid dust may also cause bronchitis and
asthma. Prolonged contact with stearic acid can cause skin and
eye irritation, and may be toxic upon ingestion. Long-term
exposure to stearic acid may also lead to cancer.The ingestion of
stearic acid is generally considered to be safe and non-toxic, but it
can cause gastrointestinal and skin irritation if ingested in large
amounts. Prolonged inhalation of stearic acid fumes can also
cause respiratory irritation.
Control Measures:
Stearic acid should be handled with care and stored in a well-
ventilated area. It should be kept away from sources of heat and
ignition, and it should be kept away from food products and other
materials that may be contaminated with stearic acid. In the event
of a spill, it is important to promptly clean up spills in order to
minimize the risk of exposure. Appropriate protective clothing,
such as goggles, a face mask and gloves
Results
Table 1- Water Cooling in a can
Error is equal to piece of equipment/2
Error for thermometer is 1/2: ±0.5
, Time(min) Temp(ºC)
7.5 81.0
8.0 80.0
8.5 80.0
9.0 78.5
9.5 79.0
10.0 77.5
10.5 77.0
11.0 77.0
11.5 77.0
12.0 77.0
12.5 76.5
13.0 74.0
13.5 74.0
14.0 72.0
14.5 72.0
45.0 71.5
15.5 71.0
16.0 71.0
16.5 70.0
17.0 69.5
17.5 69.0
18.0 68.0
18.5 68.0
19.0 67.5
19.5 67.0
20.0 66.0
20.5 66.0
24.0 65.5
22.0 65.0
22.5 65.0
23.0 64.0
23.5 63.5
24.0 63.5
24.5 62.5
25.0 62.0
