Calorimetry - Cooling curve of paraffin wax
Calorimetry is a form of scientific investigation, requiring the use of a calorimeter
to measure the state, phase, and heat changes of chemical reactions. The
calorimeter is a container that can be used with the thermometer, like a beaker
The thermometer measures the temperature during the reaction and the heat
exchanges heat with the surrounding environment. Several common uses include
monitoring endothermic reactions,and monitoring physical phase changes, for
example on freezing liquid turns solid and melts, in which solid turns liquid. is also
used to measure specific heat. In the study,
the substance used in this experiment is paraffin wax. Paraffin is a colorless, soft,
flammable solid made from petroleum, or coal. It is made up of a mixture of
hydrocarbon molecules twenty to forty carbon atoms. It is a solid at room
temperature, melting point is about 37 ° C (99 ° F), and its boiling point is above
370 ° C (698 ° F). melting point between about 46 and 68 °C (115 and 154 °F) and
a density of around 900 kg/m3.It is insoluble in water the chemical formula for
paraffin wax is is CnH2N + 2
Risks assessment
The use of glass tube boiling and the use of liquid thermometer has risk of
accident of glass break which can cause wounds and injuries in the laboratory so
we can prevent this by wearing protective clothing and be extra careful when
handling glass.
risks of substance paraffin wax include: if paraffin get in contact with the skin
while hot it can cause burns, so its best to wear gloves when handling melted
paraffin wax. Inhalation of paraffin base may irritate the eyes and respiratory
tract. So it is best for the safety to wear goggles.
Risk of burns by hot boiling water when in contact with skin the person handling
the water and any other hot substances should be extremely carful and it is
essential to wear PPE and laboratory clothes.
, Equipment:
boiling tube
thermometer to measure heat
20 grams of paraffin
heating equipment (boiling water)
200ml beaker and 100ml water
timer
clamp
Method
First, we put 20 grams of paraffin wax into the boiling tube, then we pour 100 ml
of water into the beaker, then we hold the boiling tube and put it into the beaker,
and then we used the clamp for this . We first calibrate the digital thermometer
and the alcohol thermometer in boiling water. First, we boiled a pot of distilled
water. Once the water boiled, we dipped the thermometer into the water and
made sure it didn't touch the side or bottom of the glass. Therefore, since the side
surface of the beaker may be affected by the surrounding temperature, the result
will not be abnormal. Once the temperature reaches 100 degrees Celsius, we will
record the difference between the two thermometers and notice that the digital
thermometer is more accurate than the alcohol thermometer we used a digital
thermometer because it is more accurate, because boiling water has the closest
reading to 100 ° C and the lowest reading on ice as shown in table below
