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Edexcel - Chemistry Unit 2 - 4 June 2013 Watch

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    nice I am on in topic 2.7 hahah, so scared earlier, but got alot done today, it was really easy, I love chemistry...but I hate edexcel lol.
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    I don't think fecked quite describes my situation for unit 2. Anyone else really nervous?
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    (Original post by adi19956)
    I don't think fecked quite describes my situation for unit 2. Anyone else really nervous?
    Yep, but thats only because Edexcel can spew up any old topic and try to pass it off as chemistry - ref. baking soda in Unit 1 exam.
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    These questions are from the June 2010 paper. Could someone explain them please?
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    This Q19 (f)(i) 2nd Titre value = 27.95cm3
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    (Original post by SKK94)
    These questions are from the June 2010 paper. Could someone explain them please?
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    This Q19 (f)(i) 2nd Titre value = 27.95cm3
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    The first one is B I think. As the reaction progresses, the amount of product Y increases, and the amount of reactant X decreases untill equilibrium is reached. After this point the amount of both reactants and products remains the same. Also, the rate of decrease of X and the rate of increase of Y are not constant.

    The second one should be 27.85-28.05. The total error is 2 (0.05) which is 0.1. Add and subtract 0.1 to 27.95 to get the range.

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    Guys I have noticed the specification does not mention many points that are in the Facer book, such as the diagram of the shape of ice and how it is different in density to water, it is not mentioned in the spec but its in the book. should I cover that ?
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    (Original post by Baraf)
    Guys I have noticed the specification does not mention many points that are in the Facer book, such as the diagram of the shape of ice and how it is different in density to water, it is not mentioned in the spec but its in the book. should I cover that ?
    The George Facer book has far too much information on in relation to the specification - if it isn't in the spec, then by all means read over it and get a general idea, but dont prioritise it over explicitly mentioned material.
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    what topic does everyone find the hardest?
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    has anyone got a table or something with all the different reactions we need to know?? if you have that'd be great and i'd really appreciate it if you could upload it because oh my god there is a lot to remember
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    (Original post by charlieejobson)
    has anyone got a table or something with all the different reactions we need to know?? if you have that'd be great and i'd really appreciate it if you could upload it because oh my god there is a lot to remember
    This is something I knocked up to help me memorize the reaction pathways, you obviously have to fill in the details.

    The main ones to remember is the Amine - Haloalkane - Alcohol pathway, that seems to be a favorite to test.

    **DISCLAIMER** This is for Unit 4/5 too, so fyou can ignore the Nitriles/Acyl Chlorides/Esters etc. **DISCLAIMER**
    Attached Files
  1. File Type: docx Reaction Pathways.docx (78.6 KB, 187 views)
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    Im confused, why can HF only form one H bond per molecule if it has 3 lone pairs of electrons?
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    (Original post by Relaxedexams)
    The first one is B I think. As the reaction progresses, the amount of product Y increases, and the amount of reactant X decreases untill equilibrium is reached. After this point the amount of both reactants and products remains the same. Also, the rate of decrease of X and the rate of increase of Y are not constant.

    The second one should be 27.85-28.05. The total error is 2 (0.05) which is 0.1. Add and subtract 0.1 to 27.95 to get the range.

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    Thanks!!
    Regarding the first question, how would the graph differ if the reaction was 2X <--> Y ?
    Will the line for X just be higher?
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    (Original post by Lili94)
    Im confused, why can HF only form one H bond per molecule if it has 3 lone pairs of electrons?
    There's no lone pair of electrons... I think you may be forgetting that 1st/1s shell in hydrogen can only hold 2 electrons
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    (Original post by posthumus)
    There's no lone pair of electrons... I think you may be forgetting that 1st/1s shell in hydrogen can only hold 2 electrons
    but i thought there are three lone pairs on the fluorine? why can't there be a hydrogen bond to each one?
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    (Original post by Lili94)
    but i thought there are three lone pairs on the fluorine? why can't there be a hydrogen bond to each one?
    I'm pretty sure they can only be bonded dative covalently as they are lone pairs, not unpaired electrons
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    (Original post by Lili94)
    but i thought there are three lone pairs on the fluorine? why can't there be a hydrogen bond to each one?
    Oh damn I'm such a moron I think because there aren't enough hydrogens to bond to the Fluorine, so I would say on average there can be only 1 hydrogen bond between HF molecules.
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    (Original post by Locked_box)
    I'm pretty sure they can only be bonded dative covalently as they are lone pairs, not unpaired electrons
    (Original post by posthumus)
    Oh damn I'm such a moron I think because there aren't enough hydrogens to bond to the Fluorine, so I would say on average there can be only 1 hydrogen bond between HF molecules.
    oh i see thanks
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    POP Q!
    ~~~~~~

    What reagent (and in what?) would you use to reduce a Ketone back to an Alcohol?
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    (Original post by HarryMWilliams)
    POP Q!
    ~~~~~~

    What reagent (and in what?) would you use to reduce a Ketone back to an Alcohol?
    LiAlH4, in dry ether.
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    In QWC (*) questions are we allowed to write in bullet points?
 
 
 
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