Introduction
The accuracy of the instruments we use to measure the physical quantities around us is crucial in today's
society. Accurate measurements are essential when drawing conclusions in a variety of fields, including
weather, medicine, the automotive industry, and agriculture. In these practical experiments will be
conducted to see if a normal and electric thermometer can give us theorized values of the melting and
boiling points of water and using the knowledge of cooling curves to draw and compare if the
thermometers allowed to draw a smooth cooling curve. Then the graph will be studied to show all
stages of state change presents on the graph.
Chapter 1: Calibration
Section 1: Calibration
During the calibration assessment of the two thermometers (Digital Thermometer and Normal
Thermometer), we utilized the known theoretical vales of water, this included the boiling point and the
melting point. So therefore, the accuracy of the thermometers can be determined by how close the
value for boiling point of water is to 100° and how close the value on the thermometer is to the melting
point of water which is 0°.
Equipment
• Normal thermometer
• Digital Thermometer
• Boiling water
• Freezing water
Risk Assessment
It was crucial to conduct the operations carefully throughout this practical, especially when using
chemicals and any glass equipment. It was crucial to adhere to CLEAPSS Hazards requirements as well as
lab rules. It was crucial to know what to do in potentially dangerous situations.
Any physical risks that can occur include cuts from glass equipment or broken bones. This can happen as
a result of malfunctioning equipment, obstructions inside the lab, or slips or trips from spills. It is crucial
to look for spills and clean them up right once to reduce this risk. Underneath benches, bags, coats, and
stools should be kept out of sight. Before using glass equipment, it should be managed gently and
examined for cracks or breakage. Equipment made of glass that has any breaks should not be utilised.
These dangers have a medium level of severity, but there is a high likelihood that they will materialise. If
any of these hazards actually materialise, a lab supervisor needs to be notified right away. These
experiments also make use of a Bunsen burner. When working with flames, risks that can occur include
burns, and things igniting. At all times, it is crucial to wear safety eyewear and a lab coat. When not in
use, the Bunsen burner must be on a safety flame so that it can be seen clearly. Hair must be held back
to prevent it from catching fire. Additionally, it is crucial that the lab has adequate ventilation. An
instructor must be informed right away if any flame-related accidents happen so that they can take the
appropriate measurements. For these kinds of investigations, chemical hazards pose a considerable
danger and have a comparatively high likelihood of occurring. There are dangers associated with several
substances. If consumed, stearic acid is poisonous. It could irritate your eyes, skin, and respiratory
, system in addition to your skin and skin tissue. While less dangerous than stearic acid, paraffin wax can
nevertheless burn the skin severely and harm the eyes when it is molten. It is critical to become familiar
with the chemical hazard signals for any substances containing chemicals. Wearing personal safety
equipment (PPE) such a lab coat, eye protection, and gloves is crucial when conducting the practical.
Hair must be tied back at all times. It may also cause eye injury. In order to prevent cross contamination,
it is important to dispose of chemicals in the proper, labelled trash containers and use clean test tubes
for each new practical. Hands should be carefully cleansed with soap and water after each experiment
to remove any chemicals. When chemicals spill, it is crucial to make sure no skin is touched and to clean
it up very after. If the substance gets in someone's eye, they should immediately seek medical attention
and clean their eye out with water for at least 15 minutes. It is crucial to seek medical attention if it is
consumed, and if it is aggravating the person, try to encourage them to drink some milk or water to
dilute the toxin. Fresh air must be rapidly found after inhaling a chemical, and if any symptoms like
coughing or wheezing appear, immediate medical attention must be sought.
Procedure
1. Put a normal thermometer into the beaker with freezing cold water
2. Record the temperature of the cold water (theoretically zero)
3. Get hot boiling water through a kettle and pour it into a beaker carefully
4. Put a normal thermometer into the beaker with hot boiling water
5. Repeat steps 1-5 using an electric thermometer
6. Follow the calibration techniques below
Results
Boiling point Boiling point Melting point Melting point
Digital Thermometer 100 100.4 0 0.4
Normal Thermometer 100 94 0 -6
The results indicate that both thermometers are not accurate in correlation of theoretical values of the
boiling and melting point of water. This also let us identify the value by which the thermometer
inaccurate by. For the digital thermometer being (Value identified – 0.4) and for a normal thermometer
being (Value identified + 6). However, this helped us identify the most accurate one between the two
and after examining the results the conclusion portrays the digital thermometer to be more accurate
compared to the normal thermometer. Therefore, now the experiments of heating two substances can
be conducted with the digital thermometer, which will help us produce a cooling curve of the
substances.
Chapter 2: Cooling curve of substances
Introduction
We used a digital thermometer to take temperature measurements every 0.5 minutes for a total of 15
minutes while heating up both compounds. The temperature of both compounds was measured with a
regular thermometer. The results are shown in the graph below.
