Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie
Hi there,
There is an issue with role permissions that is being worked on at the moment.
If you are having trouble with access or permissions on regional forums please post here to get access: https://www.boards.ie/discussion/2058365403/you-do-not-have-permission-for-that#latest

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

1234568»

Comments

  • Registered Users Posts: 52 ✭✭booblefoop


    Actually, will I lose marks for writing "Bohr, Neils Bohr"?

    I was going to cross out the first Bohr after remembering his full name, but I thought it was quite amusing that way :pac:

    There's 0 chance an examiner would take marks off for that :P


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


    Just wondering what answers yee all put for the last 2 parts in q5:)

    I think I said something about more energy being required to remove an electron from a new shell. Can't remember exactly how I phrased it now .


    The last part I said that a line spectrum is evidence . Not sure if that's right or not though I just guessed


  • Registered Users Posts: 88 ✭✭Gabrielazap


    EoghanIRL wrote: »
    I think I said something about more energy being required to remove an electron from a new shell. Can't remember exactly how I phrased it now .


    The last part I said that a line spectrum is evidence . Not sure if that's right or not though I just guessed
    Thanks:) yeah I said about the same
    Thanks:) yeah I said about the same

    By any chance do u remember roughly what you said for why silicon has a Lowe first ionization energy value than carbon?;)
    By any chance do u remember roughly what you said for why silicon has a Lowe first ionization energy value than carbon?;)

    * lower


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


    Thanks:) yeah I said about the same

    Q3 (f) is the answer that the rate of reaction is decreased by 1/2 because sodium thiosulfate is the limiting reagent and rate of reaction is affected by concentration ?

    Q2(g) I said that c17h35 part of molecule is non polar and the coo Na part is polar and that like dissolves like. I.e polar dissolves polar

    Finally last part of 11(a)
    I said that the centre of gravity of the negative charge coincides with the centre of gravity of the positive charge .

    These ones were bugging me .
    * lower

    I think I said that silicon has a greater atomic radius than carbon so electrons are further away from nucleus . Requires less energy to remove them. Not sure if this is what they wanted .


  • Registered Users Posts: 88 ✭✭Gabrielazap


    EoghanIRL wrote: »
    I think I said that silicon has a greater atomic radius than carbon so electrons are further away from nucleus . Requires less energy to remove them. Not sure if this is what they wanted .

    I said the same:) thanks;)

    what did u say for q3 part d?;)

    Does anyone Remember what they said for q3 part d it was describe and explain the relationship of the graph


  • Registered Users Posts: 2 larkinitis


    Probably passed it, but I hated chemistry! :(:(

    Why do schools make you do a science subject when you have no interest in it?!


  • Registered Users, Registered Users 2 Posts: 15,392 ✭✭✭✭rainbowtrout


    larkinitis wrote: »
    Probably passed it, but I hated chemistry! :(:(

    Why do schools make you do a science subject when you have no interest in it?!

    That's the school's individual policy. Science subjects are not compulsory for the Leaving Cert.


  • Registered Users Posts: 160 ✭✭plmko


    larkinitis wrote: »
    Probably passed it, but I hated chemistry! :(:(

    Why do schools make you do a science subject when you have no interest in it?!

    Not all schools do that? That's horrible!


  • Registered Users Posts: 240 ✭✭Wanderer41


    I think I did the equilibrium question wrong as well :( I don't know how I did it wrong, after all the questions I had practised I would have to make a mistake in the exam :(


  • Advertisement
  • Registered Users, Registered Users 2 Posts: 86 ✭✭Caolan


    larkinitis wrote: »
    Probably passed it, but I hated chemistry! :(:(

    Why do schools make you do a science subject when you have no interest in it?!

    Same reason they make you do a foreign language - most of the 3rd level courses demand a science and european language (not all)

    it doesnt make sense when your 17/18 and are focused on something that doesnt need it- but as someone who didnt do a science at LC- it closes alot of doors later in life should you wish to apply for many courses.


  • Registered Users, Registered Users 2 Posts: 2,226 ✭✭✭robman60


    EoghanIRL wrote: »
    Q3 (f) is the answer that the rate of reaction is decreased by 1/2 because sodium thiosulfate is the limiting reagent and rate of reaction is affected by concentration ?

    I wasn't sure, but I said it reduced the rate of the reaction. I was going to say it halved it, but that would mean they were directly proportional (straight line through origin), but they were only proportional, not directly I think.


  • Registered Users, Registered Users 2 Posts: 9,599 ✭✭✭matthew8


    robman60 wrote: »
    I wasn't sure, but I said it reduced the rate of the reaction. I was going to say it halved it, but that would mean they were directly proportional (straight line through origin), but they were only proportional, not directly I think.

    For concentration it is a linear relationship so half would've been right.


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


    Caolan wrote: »
    Same reason they make you do a foreign language - most of the 3rd level courses demand a science and european language (not all)

    it doesnt make sense when your 17/18 and are focused on something that doesnt need it- but as someone who didnt do a science at LC- it closes alot of doors later in life should you wish to apply for many courses.
    In fairness, a large amount of courses in colleges DON'T require a science. A language requirement is more common, especially in the NUI.

    I agree with you that it closes some doors, but for a small minority of students those doors aren't a realistic prospect anyway ... they have no interest in or aptitude for sciences, and will struggle with them even at Junior Cert, let alone Leaving Cert.

    I would certainly agree with schools strongly encouraging students to keep on a science for LC, and to keep their options open, but a school making it completely mandatory to my mind is a step too far. It actually ends up disadvantaging those students with no aptitude for them when it comes to points etc., as they are carrying a subject that they constantly struggle with and which they never wanted in the first place.


  • Registered Users Posts: 28 Mahmoudsaid_1


    can anyone solve this equilibrium question?
    10 moles of nitrogen and 30 moles of hydrogen were mixed and allowed to come to equilibrium in a sealed 5 litre vessel. There were 15 moles of ammonia in the vessel at equilibrium. Find the number of moles of hydrogen and nitrogen present in equilibrium and hence find Kc
    N2 + 3H2 -> 2NH3


  • Registered Users, Registered Users 2 Posts: 37 ko3p


    can anyone solve this equilibrium question?
    10 moles of nitrogen and 30 moles of hydrogen were mixed and allowed to come to equilibrium in a sealed 5 litre vessel. There were 15 moles of ammonia in the vessel at equilibrium. Find the number of moles of hydrogen and nitrogen present in equilibrium and hence find Kc
    N2 + 3H2 -> 2NH3

    Here you are: i.imgur(dot)com/EkyU6hR.jpg?1


  • Advertisement
Advertisement