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!! HL Chemistry 2015 - discussion, guesses, predictions, explosions, etc.

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245

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    #32
    iang198
    Registered Users Posts: 45 ✭iang198


    Do we need to know theory on prep of Ethanal and Ethanoic acid or just to test for them??


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    #33
    Gandhai
    Registered Users Posts: 7 ✭Gandhai


    iang198 wrote:
    Do we need to know theory on prep of Ethanal and Ethanoic acid or just to test for them??

    i read the syllabus and frm wat i cud make out of it i can almost guarantee that its just the tests


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    #34
    ThatsTheShtuff
    Closed Accounts Posts: 58 ✭✭ThatsTheShtuff


    My teacher is fairly accurate at predicting (even though i hate the word!),

    Ethyne or Esterification for Organic
    Iron tablet titration
    Test for anions and Flame Tests
    WATER!!! (people seem to forget about that, it should definitely be there)
    Equilibrium
    Rates
    Trends/Discoveries/Scientists
    Option


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    #35
    FoxScientist
    Closed Accounts Posts: 5 ✭FoxScientist


    Chemistry: Definitely water theory and probably a water experiment
    Also iron tablet titration is apparently a favourite as well as the two new experiments.
    Anions and Cations might come up as third experiment either...


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    #36
    MF290
    Registered Users Posts: 715 ✭✭✭MF290


    https ://imagizer. image shack .us/v2/320xq 90/r/ 661/jZHnOw. jpg


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    #37
    Magnate
    Closed Accounts Posts: 877 ✭✭✭Magnate


    MF290 wrote: »
    https ://imagizer. image shack .us/v2/320xq 90/r/ 661/jZHnOw. jpg

    I don't do chemistry but here's the link for anyone who does, https://imagizer.imageshack.us/v2/320xq90/r/661/jZHnOw.jpg


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    #38
    sdio
    Registered Users Posts: 49 ✭sdio


    I got 0.088875 g.


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    #39
    Dianabluex
    Closed Accounts Posts: 44 ✭Dianabluex


    Chromatography very dued simple marks as well


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    #40
    Gem957
    Registered Users Posts: 12 ✭Gem957


    What's your opinion on doing an extra question? Is it worth it or is it a waste of time?


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    #41
    d1234
    Registered Users Posts: 594 ✭✭✭d1234


    Think I'll do an extra. Usually I've loads of time over so I suppose it shouldn't impact that much on the others!


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    #42
    expiiplus1
    Closed Accounts Posts: 71 ✭✭expiiplus1


    Can you still use sodium dichromate as a test for ethanol (in the yeast experiment) on the biology syllabus if it has been banned for chemistry


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    #43
    sdio
    Registered Users Posts: 49 ✭sdio


    expiiplus1 wrote: »
    Can you still use sodium dichromate as a test for ethanol (in the yeast experiment) on the biology syllabus if it has been banned for chemistry

    Yes.. the marking scheme accepts either test.


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    #44
    Noire
    Registered Users Posts: 47 ✭Noire


    Anyone have an idea on exactly how strict they are when marking the exams? Like how bad is this negative marking thing ive been hearing about :O


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    #45
    expiiplus1
    Closed Accounts Posts: 71 ✭✭expiiplus1


    Not 100% sure about the exact case of chemistry, but negative marking only usually applies if you chance your arm, like if you were asked to state a use of benzoic acid and you gave both "food preservative" and "rocket fuel." The marking can be pretty damn horrid in easy years though. In 2007, they refused to accept "addition reaction" unless you qualified it with "ionic "


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    #46
    Noire
    Registered Users Posts: 47 ✭Noire


    Ah okay :( I'm mostly worried about the synonyms for words like if the marking schemes said 'make margarine' and I put down 'production of margarine' instead.


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    #47
    OMGeary
    Registered Users Posts: 251 ✭✭OMGeary


    What exactly is negative marking ?


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    #48
    Noire
    Registered Users Posts: 47 ✭Noire


    Say a question asks for three points worth three marks each. You put down two which are right and one which is wrong. Instead of getting 6/9 marks you get 3/9 as the wrong answer cancels out the right one :(

    I'm pretty sure that's how it goes but if im wrong someone correct me!


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    #49
    OMGeary
    Registered Users Posts: 251 ✭✭OMGeary


    Noire wrote: »
    Say a question asks for three points worth three marks each. You put down two which are right and one which is wrong. Instead of getting 6/9 marks you get 3/9 as the wrong answer cancels out the right one :(

    I'm pretty sure that's how it goes but if im wrong someone correct me!


    That's encouraging :(


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    #50
    Blue giant
    Registered Users Posts: 1,336 ✭✭✭Blue giant


    I think it's more like if you gave four answers and three were correct. You would only get marked correct for two as the wrong answer would cancel out one of the correct ones. I don't think they apply it too often though.


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    #51
    dazzadazza
    Registered Users Posts: 117 ✭✭dazzadazza


    FoxScientist wrote: »
    Chemistry: Definitely water theory and probably a water experiment
    Also iron tablet titration is apparently a favourite as well as the two new experiments.
    Anions and Cations might come up as third experiment either...

    What's the other new experiment? I'm familiar with the oxidation on penylmethanol one.


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    #52
    ko3p
    Registered Users Posts: 37 ✭ko3p


    dazzadazza wrote: »
    What's the other new experiment? I'm familiar with the oxidation on penylmethanol one.

    There's only one.


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    #53
    OMGeary
    Registered Users Posts: 251 ✭✭OMGeary


    dazzadazza wrote: »
    What's the other new experiment? I'm familiar with the oxidation on penylmethanol one.

    For the clove oil one you have to be able to describe the extraction of eugonol


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    #54
    dazzadazza
    Registered Users Posts: 117 ✭✭dazzadazza


    OMGeary wrote: »
    For the clove oil one you have to be able to describe the extraction of eugonol

    Is that just shaking it in cyclohexane?


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    #55
    OMGeary
    Registered Users Posts: 251 ✭✭OMGeary


    dazzadazza wrote: »
    Is that just shaking it in cyclohexane?

    Think so, then you put it in a separating funnel and wait for it to split into the different layers


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    #56
    lc2015x
    Registered Users Posts: 44 ✭lc2015x


    Lads really struggling with what experiments to learn! Really just wanna break it down to the one's that are bound to be coming up! I know the new clove oil is one to watch for!
    Any good predictions please? Thanks a million!!


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    #57
    AlfaJack
    Registered Users Posts: 170 ✭✭AlfaJack


    Do we not have to know how to prepare ethanoic acid and ethanal anymore? Do we just have to test for them?
    http:// www .curriculumonline.ie/Curriculum/files/7b/7b6ba389-c779-4b17-a6a9-e26534f12a39. pdf


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    #58
    dazzadazza
    Registered Users Posts: 117 ✭✭dazzadazza


    lc2015x wrote: »
    Lads really struggling with what experiments to learn! Really just wanna break it down to the one's that are bound to be coming up! I know the new clove oil is one to watch for!
    Any good predictions please? Thanks a million!!

    You're joking right? What do you mean by "new" clove oil? Is it the one in the book or is there another clove oil experiment?


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    #59
    lc2015x
    Registered Users Posts: 44 ✭lc2015x


    dazzadazza wrote: »
    You're joking right? What do you mean by "new" clove oil? Is it the one in the book or is there another clove oil experiment?


    Sorry, didn't mean to write new :p yeah, one in the book!!


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    #60
    ThatsTheShtuff
    Closed Accounts Posts: 58 ✭✭ThatsTheShtuff


    dazzadazza wrote: »
    You're joking right? What do you mean by "new" clove oil? Is it the one in the book or is there another clove oil experiment?

    The clove oil one that was always there,
    as well as the extraction of eugenol - very likely!

    I think the iron tablet concentration one is also due,
    in terms of Organics, i'm thinking Ethyne.


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    #61
    MmmPancakes
    Registered Users Posts: 712 ✭✭✭MmmPancakes


    ThatsTheShtuff wrote: »
    The clove oil one that was always there,
    as well as the extraction of eugenol - very likely!

    I think the iron tablet concentration one is also due,
    in terms of Organics, i'm thinking Ethyne.

    If Iron Tablets, Ethyne and Benzoic Acid preparation come up I will probably cry with happiness


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