Download Thermal Energy of Paraffin Wax

THERMAL ENERGY OF PARAFFIN WAX
IPC – Mr. Coburn
Introduction
Paraffin wax is a hydrocarbon compound (C20H42) that contains chemical energy
in the bonds between the atoms of carbon and hydrogen.
Your task will be to measure the amount of energy released during combustion
(a chemical reaction that releases the stored chemical energy) of paraffin, and to
quantify the amount of energy per gram of the wax.
Thermal Energy is the total amount of internal energy in a substance. It is
dependent on the type of matter (particles), quantity of particles (mass) and the
average kinetic energy of the particles (temperature). The relationship between
these factors and thermal energy is expressed in the following formula.
Q = c m ∆T
Where; Q = thermal energy (calories)
c = specific heat capacity* (cal/g oC)
m = mass (grams)
∆T = change in temperature (oC)
* The specific heat capacity of water is 1 cal.
g oC
Problem Definition
How much thermal energy is contained in one gram of paraffin wax?
Material List
Beaker or Flask
Water
Tongs
Paraffin Wax Candle
Graduated Cylinder
Timing Device
Thermometer
Procedure
WARNING: Hot glassware does not appear hot. Use tongs, eye protection
and caution!!
Step 1 – Place a known quantity of water into a flask and obtain its initial
temperature.
Step 2 – Determine the initial mass of the candle
Step 3 – Ignite the candle and heat the water in
the flask for five (5) minutes.
Step 4 – Record the change in temperature ( ΔT ).
Step 5 – Determine the final mass of the candle.
Observations
Data
Show the calculations of the amount of thermal energy gained by the water for
each trial. Assume that the Law of Conservation of Energy applies, and
therefore, this quantity of energy is equal to the chemical energy released by the
wax. Recall that the specific heat capacity for water is 1 cal./g oC.
Q = c m ∆T
Conclusions
Provide the value of energy in one (1) gram of paraffin wax by dividing the
number of calories gained by the water by the mass of the candle used.