Heat Of Combustion
Fuels are chemical compounds that release useful heat on demand. Some
release heat slowly, like iron (in mitten warmers) or coal. Others release
heat very quickly, like gasoline. In this experiment, we will determine
the amount of energy that a given mass of fuel (candle wax) releases.
To do this, we will measure the amount of energy that a known mass of water
absorbs. Groups will develop and carry out their own procedures.
Heat of combustion is measured with units of energy per mass, in"J/g" of the
Notes & Hints
- Decide what information you will need to record. Prepare a procedure and
blank data table in your notebook. You may not work at the lab bench until
I have signed your procedure and data table.
- You should perform at least three trials.
- Hint #1: What is the formula for calculating heat?
- Hint #2: How do you go about measuring heat? Refer to previous
labs and your text for specifics.
- Hint #3: Decide if it is better to heat the water for a specific
amount of time, or a specific temperature change.
- Record all data properly and carefully, and show all calculations clearly.
Don't forget to label them AND describe them.
- Is the heat absorbed by the water really the same as the heat given
off by the fuel? Is it reasonable to assume this? Explain your
- Is q(water) positive or negative?
- Is q(fuel) positive or negative?
- Is Dm(candle) positive
- Is Dm(fuel used) positive
of Combustion score sheet][Heat and Energy
notes][MHS Chem page]
This lab should include a title section, purpose, procedure, data,
calculations & results, and answers for the questions in the analysis section.
Don't forget: show the calculations for the first trial but show the
final results for all trials. Include an average result.