C1.30a Investigating fuels: Student brief Practice Controlled Assessment This practice controlled assessment is about how different fuels heat water. Different hydrocarbon fuels have different numbers of carbon atoms in each molecule. Different hydrocarbons release different amounts of energy when they burn. You are going to test the hypothesis that when you heat water, the temperature rise you get for each gram of a fuel depends on the number of carbon atoms in the molecules of the fuel. Plan an investigation to test how much energy is released per gram of fuel when the fuels have different numbers of carbons atoms in each molecule.
Part A: Planning How to attempt the task: You must produce a plan. The plan must include:
•
an explanation of which equipment you need to complete the task. You may want to draw a diagram of how the equipment will be set up
• •
which variable (or variables) you will change and which you will keep the same
•
any risks linked to the practical task and how you can reduce these to make your practical task safer.
which measurements you should make to test the hypothesis, explaining how these will test the hypothesis, and including the number and range of measurements
You should check that your overall plan is clear and will produce a range of results that will test the hypothesis.
Part B: Observations You are going to test the hypothesis that when you heat water, the temperature rise you get for each gram of a fuel depends on the number of carbon atoms in the molecules of the fuel. You will test this hypothesis using your own method from Part A. You should also collect some secondary evidence on energy released by fuels.
How to attempt the task: You should decide on the number and range of measurements you will make Complete the practical task, recording your measurements clearly and accurately Collect some secondary evidence on this task Comment on the quality of the source of this secondary evidence.
Part C: Conclusions You will need your primary and secondary evidence from the Part B: Observations task and information about the method you used.
How to attempt the task: You must process your primary and secondary evidence from Part B and present these, using mathematical processes if relevant. You must produce a conclusion in which you:
• • • • •
review all of the primary and secondary evidence, then identify and deal with any anomalies draw conclusions from this processed evidence to prove or disprove a hypothesis show how the data supports the conclusion explain how you might change the method if you were going to repeat the investigation describe the primary and secondary evidence you might collect to extend your investigation and say why you would collect it.
© Pearson Education 2010. Edexcel GCSE Science Activity Pack This document may have been altered from the original.
C1.30b Investigating fuels: Observations Practice Controlled Assessment You are going to investigate how much energy is released per gram of fuel when the fuels have different numbers of carbons atoms in each molecule. You will be given the following equipment/resources: Thermometer, balance, measuring cylinder, different fuels in spirit burners, beakers, clamp and stand, heat proof mat, eye protection.
Health and Safety ●
Eye protection should be worn.
Follow these instructions when carrying out the practical: 1
Set up your heating equipment in the normal way.
2
Measure 100 cm3 of water into a beaker, and clamp the beaker above the spirit burner.
3
Take the water temperature and write it down. You are going to heat the water by 50°C, so work out what the final temperature of your water should be.
4
Select a fuel, and find the mass of the fuel and its container.
5
Place the fuel under your beaker and light the fuel.
6
Wait until the water temperature has risen by 50 °C, then put out the flame (safely!).
7
When cool, find the mass of the fuel and container again to see how much has been used up in burning
8
Calculate how much fuel was used to heat the water by 50 °C.
9
Calculate the temperature rise for each gram of fuel used.
10 Repeat the procedure for the other fuels you have available. 11 Record your observations and measurements in an appropriate way.
© Pearson Education 2010. Edexcel GCSE Science Activity Pack This document may have been altered from the original.
C1.30c Investigating fuels: Recording results Name
Practice Controlled Assessment
Class
Date
Carry out the investigation on Worksheet C1.30b Investigating fuels: Observations and use this sheet to record your results and draw a conclusion.
Recording your results 1
Record your data in this table. Fuel
Temperature of water (°C)
Mass of fuel (g)
Start
Start
End*
Mass of fuel used (g)
Temperature rise/gram of fuel (°C/g)**
End
*add 50°C to the starting temperature ** = mass of fuel used/50°C
Presenting data 2
Look at the masses of the different fuels used. What is the range of this data?
3
Draw a bar chart on the graph paper below. You will need to number the axes and label them. Use the range from question 2 to help you.
© Pearson Education 2010. Edexcel GCSE Science Activity Pack This document may have been altered from the original.
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C1.30c Investigating fuels: Recording results
Practice Controlled Assessment
Considering your results/conclusions 4
All fuels provided the same amount of heat, because they all heated the water by 50°C. Which fuel provided the most heat per gram of fuel?
5
a
Is there a relationship between the number of carbon atoms in a molecule of the fuel and the amount of heat released per gram of fuel?
b If there is a relationship, state what it is.
Evaluation 6
Was all the heat energy released by the burning fuels transferred to the water? Explain your answer.
7
Was your method good enough to compare the different fuels you tested? Explain your answer.
8
How could you improve the method to provide better quality data?
9
How could you find out how repeatable your results are?
Š Pearson Education Ltd 2010. Edexcel GCSE Science Activity Pack This document may have been altered from the original.
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