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    (Original post by krisshP)
    As an estimate for the average F332 how many marks out of the 100 are needed for an A
    Thanks
    I remember last year the grade boundaries shot quite significantly. I can't remember what they were though but it wasn't nice
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    (Original post by EstebanK0)
    I remember last year the grade boundaries shot quite significantly. I can't remember what they were though but it wasn't nice
    Yeah, on the whole it varies, has been as low as 60 before but as high as 80 (jan 12) and jan 13 was 72 (all for achieving an A). But your right, over the past few years the boundaries have risen.
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    reagents and conditions742]I remember last year the grade boundaries shot quite significantly. I can't remember what they were though but it wasn't nice [/QUOTE]

    How many marks out of 100 is it usually for an A?
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    Look at 3c in Jan 2010. Why do have to have a straight structure?
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    (Original post by krisshP)
    Look at 3c in Jan 2010. Why do have to have a straight structure?
    E/Z isomers are always straight chained
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    (Original post by cheetahs56)
    E/Z isomers are always straight chained
    No they are not
    http://www.chemguide.co.uk/basicorg/isomerism/ez.html
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    Maybe not then
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    (Original post by krisshP)
    Look at 3c in Jan 2010. Why do have to have a straight structure?
    They don't have to have a straight structure.
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    (Original post by super121)
    They don't have to have a straight structure.
    It says on the mark scheme for it
    A correct representation of but-2-energy scores 1.

    WTF is a wrong answer supposed to score 2 marks then?
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    They want 2 correct versions of it- an E isomer and a Z isomer
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    (Original post by krisshP)
    It says on the mark scheme for it
    A correct representation of but-2-energy scores 1.

    WTF is a wrong answer supposed to score 2 marks then?
    Key work is 'A'

    The mark scheme also says 'Diagrams do not have to show correct bond angles.' Suggesting that it doesn't have to be straight.
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    I do not for the life of me understand e/z isomers.
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    (Original post by tasniaa)
    I do not for the life of me understand e/z isomers.
    It's pretty simple. Just learn this generic answer:
    "E/Z or molecule X has 2 different groups attached to each carbon atom on the C=C bond. This C=C bond restricts rotation and gives rise to E/Z isomers"

    (worth like 2 or 3 marks)

    E = groups opposite
    Z = groups same side
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    (Original post by krisshP)
    One question

    What really is oxidation?

    It means loss of electrons in Redox. But what does it actually mean in organic chemistry, like saying alcohol oxidises to aldehyde then oxidises to carboxylic acid?
    Oxidation is the loss of electrons and usually means gaining an oxygen atom and losing a hydrogen atom. So when an aldehyde is oxidised to a carboxylic acid, and oxygen atom is gained. But the key part is to learn that oxidation is the loss of electrons.
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    (Original post by StephenNaulls)
    Not sure if this has tripped anyone else up, but I just did a past paper question that confused me a little.

    Normally, the reagents and conditions required for hydrogenation are: Hydrogen, high temperature and pressure and a hot nickel catalyst.

    However, the question stated that the reaction was carried about at room temperature. Therefore, a hot nickel catalyst couldn't be used. Instead you have to use platinum.

    So for hydrogenation at room temperature you need: Hydrogen and a Platinum catalyst.

    At my Sixth Form it wasn't really stressed that this was the case, so I thought I'd share in case anyone else had left it out of their revision
    Don't confuse the two:
    - Finely divided Nickel catalyst, 150 degrees, 5 atmospheres
    OR
    - Pt catalyst, RTP.

    Learn both
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    (Original post by StephenNaulls)
    I prefer to say more frequent collisions. Since f=1/T, where T is the time period, 'per unit time' would probably also be acceptable. So honestly I don't think it matters.
    The mark scheme is getting pickier and pickier I'd suggest putting 'per unit time' though I usually just add in both (i.e. more frequent collisions (per unit time))
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    (Original post by carla6600)
    It's pretty simple. Just learn this generic answer:
    "E/Z or molecule X has 2 different groups attached to each carbon atom on the C=C bond. This C=C bond restricts rotation and gives rise to E/Z isomers"

    (worth like 2 or 3 marks)

    E = groups opposite
    Z = groups same side
    Thank you so much <3
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    (Original post by booooomblastruin)
    The process used to boil volatile substances (such as alcohols) without the loss of reactants or products.

    Shown in detail on page 367 of Chemical Ideas
    thanks
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    I'm confused: do you make Halogenoalkanes from alcohols by:

    1. Shaking the ethanol with HCl at room temperature

    2. Reflux->separation->sodium hydrogen carbonate (to remove acid impurities)->separate again->anhydrous magnesium sulphate (to remove excess water->distill and collect Halogenoalkanes at around 45 degrees?

    Could someone also give me the reagents and conditions for the second one?
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    Gonna just stay up all night and do some past papers. Could somebody link me to the reagents + conditions PDF please? Idk what page in the thread it's buried in.
 
 
 
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