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**Chemistry...Before/After

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    #572
    TMCGY
    Registered Users Posts: 44 ✭TMCGY


    dmca93 wrote: »
    I said lead.

    SAme!!! but totally guess it!! :P


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    #573
    Nazata
    Registered Users Posts: 142 ✭✭Nazata


    TMCGY wrote: »
    Whats the substance that used to be added to petrol but now is stopped??

    Tetraethyl Lead was one such compound, but they might be accepting a few answers.


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    #574
    Dicksboro_man
    Registered Users Posts: 414 ✭✭Dicksboro_man


    TMCGY wrote: »
    Whats the substance that used to be added to petrol but now is stopped??

    lead


    yeah i said the same thing for PH3 and showed them eneg differences for all the molecules..a bit of a weird question if you ask me :)


    in the last part of q8, did we all say esther b (propane metanoate) the one that has a fruity smell? :)


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    #575
    Geo10
    Registered Users Posts: 1,545 ✭✭✭Geo10


    I didn't get a chance to revise fuels and heats of rxns in ages so I was unsure about part a.... I forgot what most of those processes were about.
    Can anyone tell me what they were?? I guessed:
    (i) dehydrocyclisation
    (ii) catalytic cracking
    (iii) isomerisation


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    #576
    finality
    Registered Users Posts: 1,763 ✭✭✭finality


    Geo10 wrote: »
    I didn't get a chance to revise fuels and heats of rxns in ages so I was unsure about part a.... I forgot what most of those processes were about.
    Can anyone tell me what they were?? I guessed:
    (i) dehydrocyclisation
    (ii) catalytic cracking
    (iii) isomerisation

    I think that's right.


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    #577
    Hermione Granger
    Registered Users Posts: 169 ✭✭Hermione Granger


    Very happy with that paper overall. Loved the experiment questions, question 4 was lovely as usual as were 6 and 8. Here are my maths answers and what I thought to be kind of tricky :p Feel free to correct me !

    1 e i .12 mol/l e ii 4.38 g/l
    2 e 8 test tubes
    3 d .010729 mol/l and rmm of 58.888
    4 a 5 and 9
    5 di polar covalent and non polar covalent
    6 3 -224kj/mol
    8a Propylmethanoate

    :)


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    #578
    TMCGY
    Registered Users Posts: 44 ✭TMCGY


    Geo10 wrote: »
    I didn't get a chance to revise fuels and heats of rxns in ages so I was unsure about part a.... I forgot what most of those processes were about.
    Can anyone tell me what they were?? I guessed:
    (i) dehydrocyclisation
    (ii) catalytic cracking
    (iii) isomerisation

    Yea think i said same.. will reforming do for (i) :confused:


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    #579
    leaveiton
    Closed Accounts Posts: 1,778 ✭✭✭leaveiton


    Geo10 wrote: »
    I didn't get a chance to revise fuels and heats of rxns in ages so I was unsure about part a.... I forgot what most of those processes were about.
    Can anyone tell me what they were?? I guessed:
    (i) dehydrocyclisation
    (ii) catalytic cracking
    (iii) isomerisation

    Yep that's right! Could not think of the word "isomerisation" in the exam, was very tempted to write something stupid like "branchifying" since I knew I couldn't remember it :P Wrote branching in the end in the hope of it somehow being right :pac:


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    #580
    Hayezer
    Registered Users Posts: 652 ✭✭✭Hayezer


    Would someone explain how you do the ethene test tube one?


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    #581
    hollingr
    Registered Users Posts: 486 ✭✭hollingr


    Geo10 wrote: »
    I said lead?

    lead tetra ethyl, if they decide to be picky! :P


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    #582
    TMCGY
    Registered Users Posts: 44 ✭TMCGY


    Might be marked hard cause it was a fairly do able paper....


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    #583
    xGraceTx
    Registered Users Posts: 4 ✭xGraceTx


    I said benzene for 6 c, the one about mtbe and what used to be added to fuel. And I said it was stopped cos it was carcinogenic... Any hope for me?


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    #584
    Dicksboro_man
    Registered Users Posts: 414 ✭✭Dicksboro_man


    TMCGY wrote: »
    Might be marked hard cause it was a fairly do able paper....

    be graand :)


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    #585
    Geo10
    Registered Users Posts: 1,545 ✭✭✭Geo10


    Did anyone else have a *dream question* on the paper lol?
    I loved 11 a and c! Rutherford and Nitrogen Fixation!
    I thought 7 was brilliant too! :D


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    #586
    finality
    Registered Users Posts: 1,763 ✭✭✭finality


    xGraceTx wrote: »
    I said benzene for 6 c, the one about mtbe and what used to be added to fuel. And I said it was stopped cos it was carcinogenic... Any hope for me?

    I said that too but it's wrong :( Benzene is still present in petrol. So annoyed, I was going to write lead first :(


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    #587
    leaveiton
    Closed Accounts Posts: 1,778 ✭✭✭leaveiton


    Geo10 wrote: »
    Did anyone else have a *dream question* on the paper lol?
    I loved 11 a and c! Rutherford and Nitrogen Fixation!
    I thought 7 was brilliant too! :D

    Yes, Rutherford was lovely! :D I liked the b part of that question too! And fuels was a dream as always :P


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    #588
    ei.sderob
    Closed Accounts Posts: 108 ✭✭ei.sderob


    Could someone explain to me the heat of formation calculation? I just wrote out the heat of combustion equation for Octane and balanced it. Then did the products minus reactants and let it equal to the heat of combustion value, where did I go wrong???:P


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    #589
    TMCGY
    Registered Users Posts: 44 ✭TMCGY


    Geo10 wrote: »
    Did anyone else have a *dream question* on the paper lol?
    I loved 11 a and c! Rutherford and Nitrogen Fixation!
    I thought 7 was brilliant too! :D

    thought Q8 was a babe!! :pac:


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    #590
    mikechris1919
    Registered Users Posts: 6 ✭mikechris1919


    ivanh wrote: »
    Anyone get 1 test tube for Q2 (e) ?

    :P
    8


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    #591
    mikechris1919
    Registered Users Posts: 6 ✭mikechris1919


    Anyone get 63 for rmm in q3??


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    #592
    Helloxoxo
    Registered Users Posts: 49 ✭Helloxoxo


    Dicksboro_man wrote: »
    hollingr wrote: »
    Maths questions answers I got:

    1. b) 2.65 g Na2CO3 used

    e) i) 2.5 moles/L , ii) 91.25 g/L

    got totally different ans for those. 0.12 m/L and 4.38 g/L

    i could be wrong though

    Same!! Wooo


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    #593
    Sunny!!
    Registered Users Posts: 1,408 ✭✭✭Sunny!!


    mikechris1919 wrote: »
    Anyone get 63 for rmm in q3??

    i did!


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    #594
    ei.sderob
    Closed Accounts Posts: 108 ✭✭ei.sderob


    mikechris1919 wrote: »
    Anyone get 63 for rmm in q3??

    Think I got 59, can't really remember:/


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    #595
    xGraceTx
    Registered Users Posts: 4 ✭xGraceTx


    Oh, was the 9 (b) cobalt question on the type of catalysis Heterogenous? And I got Propan-2-ol for alcohol a in question 8. Anyone else?


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    #596
    FaoiSin
    Registered Users Posts: 789 ✭✭✭FaoiSin


    Lads it's best to stop thinking about it. Nothings gonna change :D


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    #597
    TMCGY
    Registered Users Posts: 44 ✭TMCGY


    xGraceTx wrote: »
    Oh, was the 9 (b) cobalt question on the type of catalysis Heterogenous? And I got Propan-1-ol for alcohol a in question 8. Anyone else?

    I said homogenous :? And propan-2-ol... uho...


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    #598
    iluvgreenday246
    Registered Users Posts: 46 ✭iluvgreenday246


    ei.sderob wrote: »
    I was soooo close to not seeing the fact that the marble chips weren't in excess!

    ..............what?


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    #599
    Hermione Granger
    Registered Users Posts: 169 ✭✭Hermione Granger


    1 e i .12 mol/l e ii 4.38 g/l
    2 e 8 test tubes
    3 d .010729 mol/l and rmm of 58.888
    4 a 5 and 9
    5 di polar covalent and non polar covalent
    6 3 -224kj/mol
    8a Propylmethanoate


    Anyone get the same


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    #600
    Dicksboro_man
    Registered Users Posts: 414 ✭✭Dicksboro_man


    TMCGY wrote: »
    I said homogenous :? And propan-2-ol... uho...
    same, homogenous all the way and i also threw in "which demonstrates intermediate compound theory" in case they were looking for it :)


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    #601
    Hayezer
    Registered Users Posts: 652 ✭✭✭Hayezer


    Why are alkenes more reactive than alkanes?
    And what was that weird indicator acid colour change thing in the pH question?


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