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OCR AS - Chemistry Unit F322 - Chains, energy and resource - REVISION! watch

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    (Original post by king1234)
    erm what did you get for that question a bout the atom aconomy ones
    You mean the one that asked what was better out of high atom economy or high percentage yield?
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    (Original post by StrawberryKoi)
    You mean the one that asked what was better out of high atom economy or high percentage yield?
    yh lol
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    Was the monomer butane or but-1-ene? I thought the monomer was but-1-ene. The original would have been but-1-ene if it had not gone through the process of polymerisation but it had.
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    (Original post by king1234)
    yh lol
    I chose higher atom economy because a low atom economy results in the formation of by-products which can be hard to dispose off, blah blah, the environment blah blah blah. What did you choose?
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    (Original post by king1234)
    could you draw it out here lol if you dont mind how it would look and how would the other two look when you add hbr
    I can't draw it, but i found a link to a picture:

    http://www.arb.ca.gov/db/solvents/so...yclohexane.gif

    I'm still not certain if its right, but here is the picture. I think adding hydrogen to this could make it straight chain, but its the opposite of reforming, and we don't need to now about it for unit 2.
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    (Original post by racheatworld)
    I already posted this answer quite a few pages up, let me find it..


    The equilibrium question was asking you why it took shorter time for the reaction to get into a dynamic equilibrium with pressure increase. Basically, this was rate of reaction increasing, more particles per unit volume, more frequent collisions, more successful collisions etc.

    Then it also said why does the composition of the mixture not change with an increase in pressure? This is because increase in pressure favours the side with the least gaseous moles, in the equation both sides had an equal number of gaseous moles (both had 2) so position of equilibrium did not change, there was no NET effect on composition.
    how many marks was the equilibrium question before the 5 mark one worth ?
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    HATED this paper. Some really vague 2 markers, that i feel i may have dropped too many marks on,
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    what did they ask u to define in the equation when they started u off with "sum of..." was it atom economy or percentage yield ?
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    (Original post by Yarpie)
    Was the monomer butane or but-1-ene? I thought the monomer was but-1-ene. The original would have been but-1-ene if it had not gone through the process of polymerisation but it had.
    I also said but-1-ene. If it was butane, you couldn't make a polymer as there are no double bonds. If is was but-2-ene, which was really the only other possibility, then there would have been a methyl group (CH3) attached to each carbon atom in the chain shown.

    (Original post by StrawberryKoi)
    I chose higher atom economy because a low atom economy results in the formation of by-products which can be hard to dispose off, blah blah, the environment blah blah blah. What did you choose?
    Same-high atom economy means less waste-with less waste to dispose of, its more economically viable and more sustainable.
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    (Original post by Jim Lee)
    I can't draw it, but i found a link to a picture:

    http://www.arb.ca.gov/db/solvents/so...yclohexane.gif

    I'm still not certain if its right, but here is the picture. I think adding hydrogen to this could make it straight chain, but its the opposite of reforming, and we don't need to now about it for unit 2.
    thanks thats what i got how about addition of hbr one
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    (Original post by kimmey)
    what did they ask u to define in the equation when they started u off with "sum of..." was it atom economy or percentage yield ?
    im an idiot i dropped a mark on that just did desired prodicts / total products didnt mentional mass will i have lost the mark
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    (Original post by king1234)
    im an idiot i dropped a mark on that just did desired prodicts / total products didnt mentional mass will i have lost the mark
    so did they want u to define atom economy ?
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    (Original post by kimmey)
    so did they want u to define atom economy ?
    the equation wasnt it
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    (Original post by king1234)
    the equation wasnt it
    yhh thts wat i meant
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    Does anyone know what full UMS is on these papers ?
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    Guys for the 'shape question'.

    Around carbon 1 was tetrahedral and is saying symmetrical as a reason enough to get you the second mark?
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    (Original post by Flint_09)
    Guys for the 'shape question'.

    Around carbon 1 was tetrahedral and is saying symmetrical as a reason enough to get you the second mark?
    might do what did you get for that question about the alcohol secondary i wrote 2metlypropan2ol will i gte the mark as i didnt but the dashes in
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    (Original post by king1234)
    might do what did you get for that question about the alcohol secondary i wrote 2metlypropan2ol will i gte the mark as i didnt but the dashes in
    2-methyl-propan-2-ol is the correct answer but I think you do have to put dashes in it because that is the correct way of writing it...
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    when will there be an unoffical mark scheme?
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    is there an unofficial mark scheme?
 
 
 
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