G9 Integrated Science Comparison of Fuels LAB

G9 Integrated Science – Comparison of fuels LAB

In your groups, perform the experiment outlined below. Try to repeat the experiment with as many different fuels as you can in the time allowed. Think carefully about how you will record your data.

Hypothesis:

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Procedure

HEALTH & SAFETY: Wear eye protection

Clamp the beaker at a suitable height to allow room for the spirit burner to be placed below. Allow a gap of around 2-5 cm between the base of the flask/can and the top of the spirit burner. This gap may need to be adjusted depending on the height of the flame.

Using the measuring cylinder, fill the beaker with 100 cm3 of water.

Using the thermometer, measure and record the initial temperature of the water.

Take the mass of the spirit burner (and cap) containing the fuel and record the initial mass and name of the fuel in a suitable table.

Place the spirit burner on the heat-resistant mat under the beaker, remove the cap, and light the wick.

Allow the fuel to heat the water for a fixed time of 5 minutes. Use a glass rod or the thermometer to stir the water gently whilst the fuel burns.

Replace the cap on the spirit burner to extinguish the flame.

Record the final temperature of the water using the thermometer. Work out the temperature change.

Reweigh the spirit burner and cap. Work out the mass of fuel used.

Repeat the experiment for different fuels using 100 cm3 of fresh cold water each time.

You will use the formula q = m x c x ΔT to calculate the amount of energy given off by each fuel. Here is a sample calculation:-

Initial temperature = 20°CInitial mass = 5.32g

Final temperature = 35°CFinal mass = 4.48g

Temperature change = 35 – 20 = 15°CMass change = 5.32 – 4.48 = 0.84g

Amount of energy given off:

q = mass of water x specific heat capacity of water xΔT

q = 50g x 4.2J/g/°C x 15°C

q = 50 x 4.2 x 15 = 3150J

This is the amount of energy in 0.84g. We need to find out the amount of energy in 1g.

Amount of energy in 1g = 3150J = 3750J

0.84g

Tasks

Data Collection and Processing

Draw a clear raw data table that includes initial temperature, final temperature, initial mass and final mass for each of the fuels you tested.
Don’t forget to state clearly in the column heading what that column represents, and remember the units.
Give a clear, descriptive title for your data table.
Draw a clear processed data table that includes the type of fuel, the temperature change, the mass change and the amount of energy given out.
Remember title, correct column headings and units.
Check your data is given to an appropriate and consistent level of accuracy.
Draw a bar graph, with type of fuel on the x-axis and amount of energy given off on the y-axis.
Make sure your graph has a suitable title and that the axes are correctly labeled with units.

Conclusion

Write a clear and detailed conclusion that is based on the correct interpretation of your results.
State whether your data supports your hypothesis or not.
Try to explain why some fuels are better than others for giving out heat energy.
Look up energy content per gram for each of the types of fuels you tested. How does your data compare to these values?

Evaluation

List all the weaknesses and sources of error in your experiment.
For each weakness, discuss how it might have had an impact on your data, and whether it was a major or relatively minor error.
For each weakness suggest a specific and realistic improvement that would improve this experiment next time.