Photo AI
4. Ethanol can be used as a liquid fuel - Edexcel - GCSE Chemistry - Question 4 - 2018 - Paper 1
Question 4
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... show full transcript
Worked Solution & Example Answer:4. 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
The actual temperature rise is much less than the theoretical value due to heat loss to the surroundings, such as the beaker and air. Even in a perfect system where ethanol burns completely, some energy is lost as heat that does not transfer to the water.
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, using a draught shield could help to minimize heat loss to the environment. Additionally, ensuring the flame is directly underneath the beaker and using more efficient burners can help maximize heat transfer to the water.
Step 3
Step 4
Give three reasons why ethanol, propanol and butanol are members of the same homologous series.
Answer
-
They all contain a hydroxyl (-OH) functional group, indicating they are alcohols.
-
Each subsequent compound differs by a -CH₂- group in its molecular formula, maintaining a consistent structure throughout the series.
-
They share similar chemical properties, such as undergo similar reactions, including combustion and oxidation.
Step 5
Step 6