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****Leaving Certificate Chemistry [All Levels] Before and After Discussion****

245678

Comments

  • Registered Users Posts: 160 ✭✭plmko


    I'm trying to go through the course these days with a mindset that the questions may be asked differently or perhaps questions we've never seen before; it's very possible!

    I think if you prepare yourself for a surprise you might be able to handle that surprise in the exam better.


  • Registered Users, Registered Users 2 Posts: 901 ✭✭✭xLisaBx


    I'm dreading chemistry :/


  • Registered Users Posts: 240 ✭✭Wanderer41


    Chemistry is my last exam. Not looking forward to it! I need to get an A1 for a UK offer but I feel like this year will be a tough exam or that I will write something silly even though I know the answer!
    Does anyone have any mock papers they could share? Or does anyone have the DEB 2013 or 2014 mock solutions?
    Really hoping it goes well for us all and that they don't throw anything too bad at us :/


  • Closed Accounts Posts: 913 ✭✭✭MacBizzle


    Wanderer41 wrote: »
    Chemistry is my last exam. Not looking forward to it! I need to get an A1 for a UK offer but I feel like this year will be a tough exam or that I will write something silly even though I know the answer!
    Does anyone have any mock papers they could share? Or does anyone have the DEB 2013 or 2014 mock solutions?
    Really hoping it goes well for us all and that they don't throw anything too bad at us :/

    I could send you this year's DEB mock if it's any use?


  • Registered Users, Registered Users 2 Posts: 901 ✭✭✭xLisaBx


    I'm dreading chemistry :/


  • Registered Users Posts: 240 ✭✭Wanderer41


    MacBizzle wrote: »
    I could send you this year's DEB mock if it's any use?

    That would be great if you could! Are you able to send it by PM? I would really appreciate it but if it takes too long or anything it's fine :) Thanks :)


  • Closed Accounts Posts: 913 ✭✭✭MacBizzle


    Wanderer41 wrote: »
    That would be great if you could! Are you able to send it by PM? I would really appreciate it but if it takes too long or anything it's fine :) Thanks :)

    I'll go find it there and send it on :)


  • Registered Users Posts: 7 rocco123


    How leniant are correctors then marking, do answers have to be exactly the same as the marking scheme or how does it work, this is my only worry for chem


  • Registered Users Posts: 57 ✭✭eefah


    marno21 wrote: »
    xLisaBx wrote: »
    Anyone else here get an awful feeling they could do a biology with this paper this year?

    What happened with biology?

    ... I thought it went fairly well...


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  • Registered Users Posts: 240 ✭✭Wanderer41


    MacBizzle wrote: »
    I'll go find it there and send it on :)

    Thanks a million, I really appreciate it :)
    rocco123 wrote: »
    How leniant are correctors then marking, do answers have to be exactly the same as the marking scheme or how does it work, this is my only worry for chem

    I think it says in the marking schemes that other answers are acceptable if they are correct, as in not all answers are listed. However I think for definitions especially you have to have the bold text.


  • Registered Users Posts: 7 rocco123


    Wanderer41 wrote: »
    Thanks a million, I really appreciate it :)



    I think it says in the marking schemes that other answers are acceptable if they are correct, as in not all answers are listed. However I think for definitions especially you have to have the bold text.

    Yeah I suppose, but say for a question on rates of reaction on one of recent years, making schemes more collisions are effective if I say more effective collisions will I get the marks?


  • Closed Accounts Posts: 913 ✭✭✭MacBizzle


    Anyone else want the DEB paper?


  • Registered Users Posts: 240 ✭✭Wanderer41


    rocco123 wrote: »
    Yeah I suppose, but say for a question on rates of reaction on one of recent years, making schemes more collisions are effective if I say more effective collisions will I get the marks?

    I expect so, yes. Try not to worry about it. If you have the correct answer you will get the marks. At the beginning of the marking scheme it says that the answers provided are not the only answers acceptable. Just be careful for definitions but your example about rates should be fine.


  • Registered Users Posts: 7 Murky013


    For exp, it's either %water of crystallization, iron tablets or vinegar titration.

    For organic its either ethylene, ethanal or ethanoic acid one

    That's my gut feeling imho


  • Registered Users, Registered Users 2 Posts: 910 ✭✭✭little sis...


    I was feeling ok about chemistry before I read some of the posts here o_O
    Murky013 wrote: »
    For exp, it's either %water of crystallization, iron tablets or vinegar titration.

    For organic its either ethylene, ethanal or ethanoic acid one

    That's my gut feeling imho

    Ethylene?


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  • Registered Users Posts: 7 Murky013


    Ethylene?

    Sorry I meant ethyne. Feckin' autocorrect. :P


  • Moderators, Entertainment Moderators, Science, Health & Environment Moderators Posts: 14,460 Mod ✭✭✭✭marno21


    World Cup 2 - 0 Chemistry study :/

    What I meant abotu the biology is the biology paper was different to all the other years this year. None of the usual topics and strong emphasis on lesser stuff.

    Imagine a paper this year with no atomic theory as q5 etc. :/ (sorry for scaring some of ye)


  • Closed Accounts Posts: 913 ✭✭✭MacBizzle


    marno21 wrote: »
    World Cup 2 - 0 Chemistry study :/

    What I meant abotu the biology is the biology paper was different to all the other years this year. None of the usual topics and strong emphasis on lesser stuff.

    Imagine a paper this year with no atomic theory as q5 etc. :/ (sorry for scaring some of ye)

    Please stop.


  • Registered Users, Registered Users 2 Posts: 910 ✭✭✭little sis...


    Why does everyone think it will all go wrong THIS year?
    Who cares if another person is setting it? It's hardly going to have some dramatically different layout and question types.
    Why don't we all get excited about the fact it may well be a lovely paper :D


  • Moderators, Entertainment Moderators, Science, Health & Environment Moderators Posts: 14,460 Mod ✭✭✭✭marno21


    My apologies for the negativity :p

    I won't say what I was going to say next

    Easy experiment questions, 3 atomic theory, 2 fuels + heats of reaction + 2 water anyone? :D


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  • Registered Users, Registered Users 2 Posts: 95 ✭✭accountname


    MacBizzle wrote: »
    Anyone else want the DEB paper?

    If you don't mind? :rolleyes:


  • Registered Users Posts: 98 ✭✭WoolyAbyss


    Do we need to know the diagrams for the organic experiments or do they always give them?
    The ethanal and ethanoic acid ones would be horrible to draw.


  • Registered Users Posts: 2 Soapndglory


    WoolyAbyss wrote: »
    Do we need to know the diagrams for the organic experiments or do they always give them?
    The ethanal and ethanoic acid ones would be horrible to draw.

    Yes you have to be able to draw all the apparatus cus they can ask on it and it'll be worth a fair few marks! My teacher has drilled us to be able to draw them in under 4 minutes!!


  • Registered Users Posts: 160 ✭✭plmko


    Could anyone explain the heat of neutralisation experiment with HCl and NaOH please? I know it came up last year but just incase it appears in Section B.

    What's the timing for Chemistry? Twenty mins per question or..?


  • Closed Accounts Posts: 913 ✭✭✭MacBizzle


    plmko wrote: »
    What's the timing for Chemistry? Twenty mins per question or..?

    22 and a half minutes per question if you want to get 8 done.

    20 per question and you'll get 9 done, which I'll be doing because I'm bound to mess up one question :p


  • Registered Users, Registered Users 2 Posts: 95 ✭✭accountname


    plmko wrote: »
    What's the timing for Chemistry? Twenty mins per question or..?

    22 mins per question. You'll probably find you get them done quicker than this, so you should have plenty of time for an extra question :)

    For the HCl and NaOH, just know the formula for it and the units you have to convert the figures to. If they ask it in Section B I'd only see them asking a calculation for it


  • Registered Users Posts: 160 ✭✭plmko


    For the HCl and NaOH, just know the formula for it and the units you have to convert the figures to. If they ask it in Section B I'd only see them asking a calculation for it

    Thanks! And how do you do the calculations?


  • Registered Users, Registered Users 2 Posts: 95 ✭✭accountname


    plmko wrote: »
    Thanks! And how do you do the calculations?

    Formula is; heat= m * c * (t2-t1)
    where m = mass in kg
    c= specific heat capacity of solution given in the question
    and t2-t1 is the difference in the temperatures
    Just sub in all them and you'll get your heat in kJ/mol

    'Tis a dirty calculation but as you said, it came up last year so I wouldn't worry too much about it :P


  • Registered Users, Registered Users 2 Posts: 4,080 ✭✭✭EoghanIRL


    Formula is; heat= m * c * (t2-t1)
    where m = mass in kg
    c= specific heat capacity of solution given in the question
    and t2-t1 is the difference in the temperatures
    Just sub in all them and you'll get your heat in kJ/mol

    'Tis a dirty calculation but as you said, it came up last year so I wouldn't worry too much about it :P

    It was on pre for heats of reaction question . If you do physics then the mc delta t thing is so easy:P


  • Closed Accounts Posts: 913 ✭✭✭MacBizzle


    Are potassium iodate and potassium iodide the same thing? :confused:


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  • Registered Users, Registered Users 2 Posts: 906 ✭✭✭Ompala


    MacBizzle wrote: »
    Are potassium iodate and potassium iodide the same thing? :confused:

    Nope, Potassium Iodate is KI03 while potassium iodide is KI.
    -ate is used in the naming of things that contain oxygen e.g iron sulfate FeSO4


  • Closed Accounts Posts: 913 ✭✭✭MacBizzle


    Ompala wrote: »
    Nope, Potassium Iodate is KI03 while potassium iodide is KI.
    -ate is used in the naming of things that contain oxygen e.g iron sulfate FeSO4

    Think we must have skipped an experiment so, or else I just wasn't listening... :rolleyes:


  • Registered Users, Registered Users 2 Posts: 906 ✭✭✭Ompala


    MacBizzle wrote: »
    Think we must have skipped an experiment so, or else I just wasn't listening... :rolleyes:

    Off the top of my head, isn't potassium iodide used in the winkler method for determining dissolved oxygen?


  • Closed Accounts Posts: 913 ✭✭✭MacBizzle


    Ompala wrote: »
    Off the top of my head, isn't potassium iodide used in the winkler method for determining dissolved oxygen?

    Yep, alkaline KI and manganese sulfate I think :p


  • Registered Users Posts: 445 ✭✭JDOC1996


    Predictions ?


  • Closed Accounts Posts: 913 ✭✭✭MacBizzle


    JDOC1996 wrote: »
    Predictions ?

    What can we really predict? Chemistry doesn't change much, all I've heard is soap being tipped, and the Hach test kit.


  • Registered Users Posts: 17 wafture


    Hach test kit?


  • Closed Accounts Posts: 913 ✭✭✭MacBizzle


    wafture wrote: »
    Hach test kit?

    You might have done the colorimeter, it's the free chlorine experiment in the water chapter.


  • Registered Users Posts: 82 ✭✭TooMuchStudy


    What are the chances of a gas question coming up this year?


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  • Closed Accounts Posts: 913 ✭✭✭MacBizzle


    What are the chances of a gas question coming up this year?

    Don't they come up every year in some shape or form?


  • Registered Users Posts: 1 craig9614


    I'm doing ordinary level and was wondering what to study over the week end .. Any predictions let me know, cheers


  • Registered Users Posts: 82 ✭✭TooMuchStudy


    MacBizzle wrote: »
    Don't they come up every year in some shape or form?

    I have no idea, done no exam paper work and don't have my exam papers with me ðŸ˜


  • Registered Users Posts: 160 ✭✭plmko


    Could someone please clarify for me what is the colour change at the endpoint of the KMnO4 and ammonium iron II sulfate titration? My book is very confusing about it.

    First they say it's faint permanent pink to permanent pink (as in it got darker which makes sense as KMnO4 is a strong purple colour) and then they say it went faint permanent pink to faint pink.

    How did it suddenly change from permanent to non-permanent?


  • Registered Users Posts: 75 ✭✭jellytots95


    plmko wrote: »
    Could someone please clarify for me what is the colour change at the endpoint of the KMnO4 and ammonium iron II sulfate titration? My book is very confusing about it.

    First they say it's faint permanent pink to permanent pink (as in it got darker which makes sense as KMnO4 is a strong purple colour) and then they say it went faint permanent pink to faint pink.

    How did it suddenly change from permanent to non-permanent?

    Is it not colourless to faint permanent pink?:confused:


  • Closed Accounts Posts: 913 ✭✭✭MacBizzle


    Is it not colourless to faint permanent pink?:confused:

    That's what I thought.

    What book is it plmko? :p


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  • Registered Users, Registered Users 2 Posts: 29,509 ✭✭✭✭randylonghorn


    I have no idea, done no exam paper work and don't have my exam papers with me ðŸ˜
    They're on examinations.ie


  • Registered Users Posts: 82 ✭✭TooMuchStudy


    They're on examinations.ie

    I know but in the exam papers they have each year certain topics come up and I don't have time to be looking through the previous exams to see what came up and what havent :p


  • Registered Users Posts: 98 ✭✭WoolyAbyss


    Can someone tell me what chemical equations I actually have to learn?
    Like do I need to learn the one in the chapters themselves our just the experiments?


  • Registered Users Posts: 160 ✭✭plmko


    Is it not colourless to faint permanent pink?:confused:
    MacBizzle wrote: »
    That's what I thought.

    What book is it plmko? :p

    Chemistry Live by Kennedy


  • Closed Accounts Posts: 913 ✭✭✭MacBizzle


    plmko wrote: »
    Chemistry Live by Kennedy

    Deccie the mad man.


    Colourless to faint permanent pink is the answer. :p


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