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Edexcel - Chemistry Unit 2 - 4 June 2013 Watch

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    (Original post by geor)
    That doesn't prove your point haha! Energy released is not the same thing as amount of fuel burned AT ALL.
    Yes, geor, is right.

    There can be carbon emissions from production of fertiliser.
    Also, energy can be generated without carbon emissions.

    So the answer is C.
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    (Original post by geor)
    That doesn't prove your point haha! Energy released is not the same thing as amount of fuel burned AT ALL.
    Yes it does because how much energy is released tells u how much fuel is burnt
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    (Original post by Al_Chemist)
    Yes, geor, is right.

    There can be carbon emissions from production of fertiliser.
    Also, energy can be generated without carbon emissions.

    So the answer is C.
    Then, I'm safe. :cool:
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    What was the answer to the last two questions about mechanism for global warming and anthropogenic climate change
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    Yeah hopefully not, jan 13 was realllyyyyyyyyyyyyy harsh
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    Also isn't the answer to number 7, C not A?
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    (Original post by Al_Chemist)
    Yes, geor, is right.

    There can be carbon emissions from production of fertiliser.
    Also, energy can be generated without carbon emissions.

    So the answer is C.
    C = Energy released per tonne of biofuel. (Not per tonne of biofuel burned)

    I get it now.
    Thanks geor. :cool:
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    (Original post by Sciencefella)
    Yes it does because how much energy is released tells u how much fuel is burnt
    Mate, you're wrong.

    You lost 1 mark, stop thinking you're gonna get the mark for that question.
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    (Original post by geor)
    That doesn't prove your point haha! Energy released is not the same thing as amount of fuel burned AT ALL.
    Also if u look at the yhings neede d for the growth of sugar cane phosphorus is used, where is the carbon in phosphurus??
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    (Original post by will210296)
    What was the answer to the last two questions about mechanism for global warming and anthropogenic climate change
    Global warming: *greenhouse gases can absorb IR radiation re-radiated by the earth back into the atmosphere. *The energy of the IR radiation is absorbed by the shifting dipoles causing the bonds to vibrate more. This means that energy in trapped in the atmosphere as heat (kinetic energy of particles). I think the stared ones are the major points THINK!

    Anthropogenic:Natural changes in atmosphere occur without human intervention for instance CO2 dissolving in sea water. Water vapour is a green house gas but it is natural and Human actions cause very little variation in its levels. If we tried to remove water vapour from the atmosphere is could cause dramatic climate issues and lead to famine and drought. Green house gases like CO2 are released in ever higher levels due to human actions such as the burning of fossil fuels. Anthropogenic change is caused as a direct action of human society. Therefore scientists focus much more on examples of Greenhouse gases like CO2 rather than water vapour because our actions have an impact on its levels in the atmosphere. Scientists are trying to prevent deforestation and burning of fossil fuels as well as encouraging processes like carbon capture to reduce human impact on the environment due to anthropological changes.

    Thats pretty much what i wrote, slightly less coherently as i never think as well during exams. I think that mentions most of the key points
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    (Original post by Goods)
    Global warming: *greenhouse gases can absorb IR radiation re-radiated by the earth back into the atmosphere. *The energy of the IR radiation is absorbed by the shifting dipoles causing the bonds to vibrate more. This means that energy in trapped in the atmosphere as heat (kinetic energy of particles). I think the stared ones are the major points THINK!

    Anthropogenic:Natural changes in atmosphere occur without human intervention for instance CO2 dissolving in sea water. Water vapour is a green house gas but it is natural and Human actions cause very little variation in its levels. If we tried to remove water vapour from the atmosphere is could cause dramatic climate issues and lead to famine and drought. Green house gases like CO2 are released in ever higher levels due to human actions such as the burning of fossil fuels. Anthropogenic change is caused as a direct action of human society. Therefore scientists focus much more on examples of Greenhouse gases like CO2 rather than water vapour because our actions have an impact on its levels in the atmosphere. Scientists are trying to prevent deforestation and burning of fossil fuels as well as encouraging processes like carbon capture to reduce human impact on the environment due to anthropological changes.

    Thats pretty much what i wrote, slightly less coherently as i never think as well during exams. I think that mentions most of the key points


    Thankyou, I wrote about the c02 absorbing the Ir and becoming unstable so either collide with other molecules to release the or or release it so they both reradiate it back to earth, what do you think il get? Also isn't number 7 C not A?
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    (Original post by geor)
    It was awful! 65 for an A. I thought the answers were a lot more obvious for that one though, plus almost every single question had come up before on a past paper, unlike this one. We shall see.


    Biofuels will produce CO2 when burned.
    Yes maybe but the pesticides and fertilliser dont play a role in that
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    (Original post by will210296)
    Thankyou, I wrote about the c02 absorbing the Ir and becoming unstable so either collide with other molecules to release the or or release it so they both reradiate it back to earth, what do you think il get? Also isn't number 7 C not A?
    The answer to 7 is indeed C. A is true but unrelated.
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    (Original post by Sciencefella)
    Yes maybe but the pesticides and fertilliser dont play a role in that
    Also i personally think people think they did better then they actually did because it was a very calculation and equation based papers so without a mark scheme people just assume they got the equations all correct so i would say the grade boundries would be around 60, simply because i dont think people did as well as they have anticipated
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    (Original post by geor)
    It was awful! 65 for an A. I thought the answers were a lot more obvious for that one though, plus almost every single question had come up before on a past paper, unlike this one. We shall see.


    Biofuels will produce CO2 when burned.
    do u think think the grade boundaries for this one will be higher that 61 or the same?
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    I imagine for unit one it'll be around 61 for an A and 62 for an A in unit 2
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    (Original post by will210296)
    I imagine for unit one it'll be around 61 for an A and 62 for an A in unit 2
    How much for a B for unit 2?

    Posted from TSR Mobile
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    I have completed the unofficial mark scheme for this exam (Unit 2 Edexcel Chemistry).

    You can view it here:

    http://www.thestudentroom.co.uk/show....php?t=2372956
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    Booooooom 76/80
    120 in Chem 2 and Unit 1 physics now :P
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    I think I dropped a maximum of 22 marks according to the unofficial mark scheme...what grade would 58/80 be?
 
 
 
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