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Ethanol can be used as a liquid fuel - Edexcel - GCSE Chemistry - Question 4 - 2018 - Paper 1
Question 4
Ethanol can be used as a liquid fuel. A student investigates how much heat energy is released when a known mass of ethanol is burned. The apparatus is set up as sh... show full transcript
Worked Solution & Example Answer:Ethanol can be used as a liquid fuel - Edexcel - GCSE Chemistry - Question 4 - 2018 - Paper 1
Step 1
Give a reason why, even if the ethanol burns completely, the actual temperature rise is much less than the theoretical value.
Answer
Even if the ethanol burns completely, heat energy can be lost to the surroundings, including the metal can and air, rather than being fully transferred to the water. Additional factors like heat being absorbed by the can also contribute to the lower temperature rise.
Step 2
Explain how the method described above could be improved to give a temperature rise closer to the theoretical value.
Answer
To improve the method, one can use a draught shield around the apparatus to reduce heat loss to the surrounding air, or ensure that the flame directly touches the beaker for a longer duration. Increasing the amount of ethanol or using a more efficient burner could also help maximize heat transfer.
Step 3
Step 4
Give three reasons why ethanol, propanol and butanol are members of the same homologous series.
Answer
- They all have the same functional group, which is the hydroxyl group (-OH).
- They each differ by a -CH₂ unit in their molecular formula.
- They exhibit similar chemical properties, such as undergoing combustion and oxidation reactions.
Step 5
Step 6