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

2

Comments

  • Registered Users, Registered Users 2 Posts: 37 ko3p


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

    There's only one.


  • 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


  • 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?


  • 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


  • 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!!


  • 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


  • 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?


  • 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!!


  • 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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  • Registered Users, Registered Users 2 Posts: 712 ✭✭✭MmmPancakes


    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


  • Closed Accounts Posts: 58 ✭✭ThatsTheShtuff


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

    Me too!!
    I would definitely study the water chapter well also,
    and the experiments to go with it, since it wasn't up last year.


  • Registered Users Posts: 2 lorc43


    This is what i'm going to be studying over the next few days. if anyone can give me any extra tips or advice i'd really appreciate them!

    Section A EXPERIMENTS: in order of likelihood/ones which I will focus on most. As there are so many experiments, i just don't think SEC are going to bringup the same ones from 2014,2013,2012. But with their report on predictability in the LC, and whats already come up on my other exams, they might do just that.

    Q1 (tirations/volumetric analysis experiments)
    Iron tablet
    sodium thiosulfate,
    % ethanoic acid in water,
    hardness of water,
    in a sample percentage of hypochlorite in bleach. They are 2011,2010,2009,2008,2007. hoping the rest won't come up again.

    Q2 (organics) I am excluding 2014 (soap) and the new experiment, Will SEC really put it up the first year its on? I have never even seen it.
    Ethyne,
    extraction of clove oil
    chromatopgraphy,
    ethene (it is a possibility)


    Section B (6 questions) practicing the following questions and learning all definitions:
    1 Organic chemistry
    2 History Of Chem / Trends
    3 Rates of Reaction
    4 Equilibrium
    5 Water
    6. Mechanism


  • Registered Users, Registered Users 2 Posts: 594 ✭✭✭d1234


    Completely forget how to calculate Le Chateliers principle :( Any tips :)


  • Registered Users, Registered Users 2 Posts: 712 ✭✭✭MmmPancakes


    d1234 wrote: »
    Completely forget how to calculate Le Chateliers principle :( Any tips :)

    Calculate? Do you mean calculate the equillibrium constant? (Kc)


  • Closed Accounts Posts: 44 Dianabluex


    d1234 wrote: »
    Completely forget how to calculate Le Chateliers principle :( Any tips :)

    Kc=[products]over[reactants] must remember the brackets


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  • Registered Users Posts: 4 mikey00


    Probably the last exam for good few people so gonna be important. Anyone banking on stuff coming up? Anyone have any help they can give on equilibrium?


  • Registered Users Posts: 2 Notsolovely


    What's the exam technique here? I find it difficult to pick and choose questions. With biology I tried to just do the required number of questions but eventually felt so **** that I ended up doing them all. I have a feeling chemistry will be the same for me. Anyone else planning on doing this?


  • Registered Users, Registered Users 2 Posts: 594 ✭✭✭d1234


    Calculate? Do you mean calculate the equillibrium constant? (Kc)

    Yup, that's the one :) And then how do I answer a question like say what is the effect of adding more reactant / increasing heat / catalyst etc. Can never remember those bad boys :( Thanks :)


  • Registered Users Posts: 11 Bsd


    With new experiments brought in im not sure. What are the experiments we have to study from chapters 22 and 23 organic chemistry?


  • Registered Users Posts: 46 Iamtheduchess


    Guys am I still safe for the A1 if I leave out Electrochemistry and rates of reaction? I just didn't learn them as we were doing them and it's a lot of work when I could be revising stuff I'm good at at this stage!
    Thanks


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  • Registered Users Posts: 45 iang198


    Does anyone actually know for definite if we have to know the theory on preparation of Ethanal and Ethanoic acid for section B?
    The booklet on the changes by the Dept. doesn't say anything about us knowing the theory of them but my Revision says we do..


  • Registered Users Posts: 80 ✭✭gabsy


    Guys am I still safe for the A1 if I leave out Electrochemistry and rates of reaction? I just didn't learn them as we were doing them and it's a lot of work when I could be revising stuff I'm good at at this stage!
    Thanks

    I'm also hoping for an A and I'm definitely leaving out electrochemistry as it only comes up as a part of q10 or 11 and I'm hoping I'll be able to get my marks from the others.On the other hand rates of reaction is a very very important chapter in my opinion,it is very likely to come up in section A and if it's not there it will definitely be in Section B.It's an easy question If you know your stuff but I guess that's the same case with everything.But I highly recommend to leave out electrochemistry and don't waste your time :) good luck !


  • Registered Users Posts: 46 Iamtheduchess


    gabsy wrote: »
    I'm also hoping for an A and I'm definitely leaving out electrochemistry as it only comes up as a part of q10 or 11 and I'm hoping I'll be able to get my marks from the others.On the other hand rates of reaction is a very very important chapter in my opinion,it is very likely to come up in section A and if it's not there it will definitely be in Section B.It's an easy question If you know your stuff but I guess that's the same case with everything.But I highly recommend to leave out electrochemistry and don't waste your time :) good luck !

    Ok thanks so much, I just find it difficult but I'll try give it a go!


  • Registered Users Posts: 11 Bsd


    Chapter 22 and 23 experiments?


  • Closed Accounts Posts: 894 ✭✭✭Corkgirl18


    d1234 wrote: »
    Yup, that's the one :) And then how do I answer a question like say what is the effect of adding more reactant / increasing heat / catalyst etc. Can never remember those bad boys :( Thanks :)

    Increasing pressure shifts the equilibrium to the side with the least amount of molecules. e.g. in 3H2 + N2 --> 2NH3 an increase in pressure will result in more ammonia being formed. This only works in an equation is in gaseous form

    A catalyst doesn't change the position of the equilibrium, just comes to equilibrium faster.

    Temperature depends on if the reaction is endothermic or exothermic. If the forward reaction is exothermic, cold temperatures will drive the reaction forward and vice versa.
    Guys am I still safe for the A1 if I leave out Electrochemistry and rates of reaction? I just didn't learn them as we were doing them and it's a lot of work when I could be revising stuff I'm good at at this stage!
    Thanks

    I'd also recommend studying rates. Just be able to draw your graph and calculate instantaneous rate, learn your nature of reactants and types of catalysis. You're most of the way there then! Use studyclix to practice previous questions as they are very repetitive.


  • Registered Users Posts: 46 Iamtheduchess


    Corkgirl18 wrote: »
    I'd also recommend studying rates. Just be able to draw your graph and calculate instantaneous rate, learn your nature of reactants and types of catalysis. You're most of the way there then! Use studyclix to practice previous questions as they are very repetitive.

    Thanks so much and yeah had a look at a question and it seems to be common sense kind of so I'll give it a go 😊


  • Registered Users Posts: 2 genna8


    Hey guys just wondering do we gave to learn Le Chateliers Principle experiments and if so is it all of them? Im just a btw confused cause the chemicals are banned but could they still come up?


  • Registered Users, Registered Users 2 Posts: 150 ✭✭EaSwe


    genna8 wrote: »
    Hey guys just wondering do we gave to learn Le Chateliers Principle experiments and if so is it all of them? Im just a btw confused cause the chemicals are banned but could they still come up?

    AFAIK No. I've been told we're only expected to know the experiment with Potassium Thiocynate.


  • Registered Users Posts: 27 evanbeaulieu


    EaSwe wrote: »
    AFAIK No. I've been told we're only expected to know the experiment with Potassium Thiocynate.

    which exp is that? iv never seen that


  • Registered Users Posts: 7 CyrilH_


    The new experiment is probably going to come up. Definitely the titrations too.

    Organic question has to be covered, it could even come up in 2 different questions but definitely one! Acid/bases would be nice too...... The 7 listed earlier are good bases to cover.
    Are those the only 7 probably guarenteed? I failed chemistry in the mocks but I've been getting help outside of school and studying it a fair bit so I hope I can get up towards a C :). Any help would be like hugely appreciated!


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  • Registered Users, Registered Users 2 Posts: 150 ✭✭EaSwe


    which exp is that? iv never seen that

    Mandatory Experiment 15: To investigate Le Chatelier's Principle using the reaction between iron (III) chloride and potassium thiocynate

    There are videos of all the experiements on Folens' website, if you sign up and add the chemistry live videos to your bag and checkout (it's free for everyone regardless of your book) https://www.folens.ie/digital-products/lc-chemistry-live-experiment-videos


  • Registered Users Posts: 27 evanbeaulieu


    EaSwe wrote: »
    Mandatory Experiment 15: To investigate Le Chatelier's Principle using the reaction between iron (III) chloride and potassium thiocynate

    There are videos of all the experiements on Folens' website, if you sign up and add the chemistry live videos to your bag and checkout (it's free for everyone regardless of your book)

    thanks


  • Registered Users Posts: 2 genna8


    EaSwe wrote: »
    AFAIK No. I've been told we're only expected to know the experiment with Potassium Thiocynate.

    Thank you! Saves a bit of learning :)


  • Registered Users Posts: 4 mikey00


    Does anyone know if we still have to know how to measure the melting point of benzoic acid or did that go with the new syllabus?


  • Registered Users, Registered Users 2 Posts: 150 ✭✭EaSwe


    mikey00 wrote: »
    Does anyone know if we still have to know how to measure the melting point of benzoic acid or did that go with the new syllabus?

    Still on

    There's no "new syllabus". Just any experiments which needed Cobalt, or Dichromate were taken off the course, because apparently they magically became dangerous now than they were before 2011:pac: and an extra step was added on to the benzoic acid experiment and clove oil experiment

    The theory of the course is the same AFAIK

    http://www.curriculumonline.ie/Curriculum/files/7b/7b6ba389-c779-4b17-a6a9-e26534f12a39.pdf


  • Registered Users Posts: 26 Chocolalla


    Do people think anion test will come up as an experiment questions???


  • Registered Users Posts: 251 ✭✭OMGeary


    Chocolalla wrote: »
    Do people think anion test will come up as an experiment questions???

    Doubt it as a full question but definitely somewhere


  • Registered Users Posts: 26 Chocolalla


    OMGeary wrote: »
    Doubt it as a full question but definitely somewhere

    Yea true I think it's too easy , they love there complex ones


  • Registered Users Posts: 117 ✭✭dazzadazza


    Chocolalla wrote: »
    Yea true I think it's too easy , they love there complex ones

    Did you call test for anions too easy? Haha I'm aiming for an A1 and I'm leaving it out completely because I can NEVER remember them. I'm also leaving out electrochemistry.


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  • Registered Users Posts: 26 Chocolalla


    dazzadazza wrote: »
    Did you call test for anions too easy? Haha I'm aiming for an A1 and I'm leaving it out completely because I can NEVER remember them. I'm also leaving out electrochemistry.

    I really want an a1 as well favourite subject what experiment and chapters you focusing on?


  • Registered Users Posts: 34 Johnjoeboy


    Do we have to learn preparartion of ethanal and ethanoic acid or have they been removed from syllabus??


  • Registered Users Posts: 117 ✭✭dazzadazza


    Chocolalla wrote: »
    I really want an a1 as well favourite subject what experiment and chapters you focusing on?

    I need the A1 for my ego since I'm pretty sure I didn't get it in biology. I did the 2009 paper today and got 91.25% in it so Theres little room for error.

    I'm focusin on the redox titrations since its been water and acid base the last two years. I still more or less know them though. For organic experiment I've gone through them all today apart from the new one. I might do that tonight or tomorrow morning.

    For the other questions I've put emphasis on atomic theory (q5) the organic questions (q6, 8 or 9) and I'm going to study my option really well tonight. The only thing I'm worried about is experiments coming up as part of long questions because I only know titrations and organic experiments.

    What are you focusing on?


  • Closed Accounts Posts: 133 ✭✭Gryffindor


    I've just spent the last hour scrolling through a chemistry jokes page on Facebook instead of actually studying. Productive as always, I am :rolleyes:
    Honestly it was worth it for coming across 'Technically vodka is always a solution' :pac:


  • Registered Users Posts: 26 Chocolalla


    Johnjoeboy wrote: »
    Do we have to learn preparartion of ethanal and ethanoic acid or have they been removed from syllabus??

    I heard there were remov d I'm only learning Ethyne , clove oil , chromatography for question 2


  • Registered Users Posts: 117 ✭✭dazzadazza


    Chocolalla wrote: »
    I heard there were remov d I'm only learning Ethyne , clove oil , chromatography for question 2

    Well only the preparation of ethanal and ethanoic acid were removed from section a.


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  • Registered Users, Registered Users 2 Posts: 103 ✭✭Cheerios


    Does anyone have a copy of the DEBS/Examcraft papers for HL? Or anyone remember what topics came up in Section B?


  • Registered Users Posts: 26 Chocolalla


    dazzadazza wrote: »
    I need the A1 for my ego since I'm pretty sure I didn't get it in biology. I did the 2009 paper today and got 91.25% in it so Theres little room for error.

    I'm focusin on the redox titrations since its been water and acid base the last two years. I still more or less know them though. For organic experiment I've gone through them all today apart from the new one. I might do that tonight or tomorrow morning.

    For the other questions I've put emphasis on atomic theory (q5) the organic questions (q6, 8 or 9) and I'm going to study my option really well tonight. The only thing I'm worried about is experiments coming up as part of long questions because I only know titrations and organic experiments.

    What are you focusing on?

    Thermochemistry, all water , trends , rates of reaction and ph hopefully the nice experiments come up like iron tablet , Ethyne, phenyl methanol , equilibrium


  • Registered Users Posts: 49 sdio


    I'm leaving out organic chemistry, I just don't have time to study it!


  • Registered Users Posts: 26 Chocolalla


    sdio wrote: »
    I'm leaving out organic chemistry, I just don't have time to study it!

    That's like the most important section of chemistry , don't give up just do the organic exam Ms questions!!


  • Registered Users Posts: 117 ✭✭dazzadazza


    sdio wrote: »
    I'm leaving out organic chemistry, I just don't have time to study it!

    You can do that. I did it for the mocks and I got 78% due to also not knowing any of the calculations. The only problem with leaving out organic though is that you have the know other topics really well.


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