AQA chemistry exam question help
07.3. Table 2 shows the enthalpies of combustion of the three fuels from the fermentation
of silverskin.
Table 2
Fuel Standard enthalpy of
combustion / kJ mol–1
Energy released per mole
of CO2 produced / kJ
ethanol, C2H5OH(l) –1371
butan-1-ol, C4H9OH(l) –2673
propanone, C3H6O(l) –1786
One way to measure a fuel’s environmental impact is to measure the amount of
energy released per mole of CO2 produced.
Complete Table 2
(From AS paper 2 2022)
I am not sure how to work out the energery released per mole of CO2 produced/kJ for each fuel
of silverskin.
Table 2
Fuel Standard enthalpy of
combustion / kJ mol–1
Energy released per mole
of CO2 produced / kJ
ethanol, C2H5OH(l) –1371
butan-1-ol, C4H9OH(l) –2673
propanone, C3H6O(l) –1786
One way to measure a fuel’s environmental impact is to measure the amount of
energy released per mole of CO2 produced.
Complete Table 2
(From AS paper 2 2022)
I am not sure how to work out the energery released per mole of CO2 produced/kJ for each fuel
Reply 1
Original post
by Slugzie(:07.3. Table 2 shows the enthalpies of combustion of the three fuels from the fermentation
of silverskin.
Table 2
Fuel Standard enthalpy of
combustion / kJ mol–1
Energy released per mole
of CO2 produced / kJ
ethanol, C2H5OH(l) –1371
butan-1-ol, C4H9OH(l) –2673
propanone, C3H6O(l) –1786
One way to measure a fuel’s environmental impact is to measure the amount of
energy released per mole of CO2 produced.
Complete Table 2
(From AS paper 2 2022)
I am not sure how to work out the energery released per mole of CO2 produced/kJ for each fuel
of silverskin.
Table 2
Fuel Standard enthalpy of
combustion / kJ mol–1
Energy released per mole
of CO2 produced / kJ
ethanol, C2H5OH(l) –1371
butan-1-ol, C4H9OH(l) –2673
propanone, C3H6O(l) –1786
One way to measure a fuel’s environmental impact is to measure the amount of
energy released per mole of CO2 produced.
Complete Table 2
(From AS paper 2 2022)
I am not sure how to work out the energery released per mole of CO2 produced/kJ for each fuel
It tells you the energy per mole of fuel burnt for each alcohol and so now you need to work out how many moles of CO2 each fuel makes.
There are two carbon atoms per molecule of ethanol, so there must be two moles of CO2 produced per mole of ethanol:
(1371 kJ per mol of C2H5OH) / (2 mol of CO2 per mol of C2H5OH) ≈ 686 kJ per mol of CO2
Can you now repeat this process for the other fuels?
(edited 1 year ago)
Reply 2
11
So for C4H9OH it would be 668kJ and for C3H6O it would be 595
Thank you,
Thank you,
Reply 3
Original post
by Slugzie(:So for C4H9OH it would be 668kJ and for C3H6O it would be 595
Thank you,
Thank you,
Those numbers sound correct. Well done.
Quick Reply
Related discussions
- aqa alevel chem
- ACC to AAA
- revision/learning resources for alevels
- 2024 A level chemistry paper
- Loreto College or Laurus Ryecroft Sixth Form
- Do to B in 2 months. Help !!
- Chemistry mocks
- A-Level Chemistry Study Group | 2025-2026
- chemistry
- chemistry vs psychology
- Are the CGP books good for these A level subjects?
- Help with grades needed asap
- Chemistry a level flashcards
- Year 10 study buddy!
- ppl who have bought exam predictions before, were they good?
- a level bio chem maths help
- AQA Biology A2 A* Revision notes
- A level revision
- How do i achieve an A* in AQA A-Level Chemistry as an A/B student
- year 11 gyg 💙
Latest
Trending
Last reply 3 hours ago
AQA A level chemistry synthetic routes map - what is the best one to memorise?Last reply 3 months ago
AQA Chemistry Electrode Potentials Conventional Representation QuestionLast reply 5 months ago
OCR B Salters A Level Chemistry 2025 Advanced ArticleLast reply 6 months ago
Help with this chemistry question? (A2, acid-base equilibria)
How The Student Room is moderated
To keep The Student Room safe for everyone, we moderate posts that are added to the site.
