Results are out! Find what you need...fast. Get quick advice or join the chat
Hey! Sign in to get help with your study questionsNew here? Join for free to post

Chemistry Practical HELP!!! urgent

Announcements Posted on
    • Thread Starter
    • 0 followers
    Offline

    ReputationRep:
    Motor vehicle environmental effects are judged on the grams of carbon dioxide emitted per kilometre of travel.
    The combustion equations for bioethanol and the alkane ethane and the energy liberated are:

    C2H5OH + 3O2 --> 2CO2 + 3H2O, delta H = -1371 kJ mol-1
    and
    C2H6 + 7/2O2 --> 2CO2 + 3H2O, delta H = -1560 kJ mol-1

    Bearing in mind that the car is driven by the energy liberated, state which fuel would be more environmentally friendly per mol on the basis of these results, giving your reason.

    There is however, another factor to be considered. Discuss this and state whether or not your initial conclusion should be altered.:eek:
    • 23 followers
    Offline

    ReputationRep:
    (Original post by SwatiL)
    Motor vehicle environmental effects are judged on the grams of carbon dioxide emitted per kilometre of travel.
    The combustion equations for bioethanol and the alkane ethane and the energy liberated are:

    C2H5OH + 3O2 --> 2CO2 + 3H2O, delta H = -1371 kJ mol-1
    and
    C2H6 + 7/2O2 --> 2CO2 + 3H2O, delta H = -1560 kJ mol-1

    Bearing in mind that the car is driven by the energy liberated, state which fuel would be more environmentally friendly per mol on the basis of these results, giving your reason.

    There is however, another factor to be considered. Discuss this and state whether or not your initial conclusion should be altered.:eek:
    You can see that both fuels produce 2 mol of carbon dioxide per mole of fuel burned.

    Also that ethane produces more energy by combustion.

    So which fuel produces more carbon dioxide per unit of energy?
    • Thread Starter
    • 0 followers
    Offline

    ReputationRep:
    (Original post by charco)
    You can see that both fuels produce 2 mol of carbon dioxide per mole of fuel burned.

    Also that ethane produces more energy by combustion.

    So which fuel produces more carbon dioxide per unit of energy?
    I know that ethane produces more energy, but it also requires more oxygen. do i say that for the second part of the question? if not, how do i word it?:confused:
    • 23 followers
    Offline

    ReputationRep:
    (Original post by SwatiL)
    I know that ethane produces more energy, but it also requires more oxygen. do i say that for the second part of the question? if not, how do i word it?:confused:
    Oxygen is irrelevant. Pollution is formation of carbon dioxide (greenhouse gas)

    You are looking for the fuel that produces more carbon dioxide per unit of energy - that will be the most polluting (from this data)
    • Thread Starter
    • 0 followers
    Offline

    ReputationRep:
    ok then thanks:headbang:

Reply

Submit reply

Register

Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?
  2. this can't be left blank
    this email is already registered. Forgotten your password?
  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. By joining you agree to our Ts and Cs, privacy policy and site rules

  2. Slide to join now Processing…

Updated: May 2, 2012
New on TSR

Exclusive Nick Clegg interview

Your questions answered by the deputy prime minister

Article updates
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.