Join TSR now and get all your revision questions answeredSign up now

OCR Chemistry F322~ 4th June 2013~ AS Chemistry Watch

  • View Poll Results: How did you find the exam
    Hard A= 72
    42
    15.22%
    It was okay A= 76
    99
    35.87%
    Easy A= 79
    75
    27.17%
    Very Easy A=82
    60
    21.74%

    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by needtosucceed=))
    this is what I was thinking. i'm pretty sure double bonds on the 1st carbon can still show e/z.
    You just should not have only one group of atoms attached to the double bond carbon, it always has to be two?


    Posted from TSR Mobile
    Offline

    2
    ReputationRep:
    (Original post by Jimmy20002012)
    You just should not have only one group of atoms attached to the double bond carbon, it always has to be two?


    Posted from TSR Mobile
    yep, so for example hclc=chcl would show e/z

    as would ClHC=CClCH3
    theres 3 carbons in that example, the double bond is on the first carbon but both carbons are still attached to 2 different atoms/groups of atoms
    Offline

    2
    ReputationRep:
    (Original post by carpe diem 123)
    Hey, where can I find this list of definitions?
    page 76 or 77
    Offline

    2
    ReputationRep:
    (Original post by Jonma)
    Can someone please explain this question?
    Attachment 222310
    I explained that to someone a few days ago, go back to somewhere between pages 60-70 and you should find it
    Offline

    0
    ReputationRep:
    (Original post by Jimmy20002012)
    Not sure that is completely right, as if you see the Jan 13 mechanism 12 marker the end product in nucleophillic substitution has an OH group as well as containingAttachment 222296 a double bond


    Posted from TSR Mobile
    that is not an alcohol though. It has an OH Group attacted ..does mean it is an alcohol . But yeah i understnad what the OP meant now :P sorryyy!
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by needtosucceed=))
    yep, so for example hclc=chcl would show e/z

    as would ClHC=CClCH3
    theres 3 carbons in that example, the double bond is on the first carbon but both carbons are still attached to 2 different atoms/groups of atoms
    How is hclc=chcl e/z isomerism as they are the same group of atoms on each carbon?


    Posted from TSR Mobile
    Offline

    0
    ReputationRep:
    (Original post by carpe diem 123)
    Hey, where can I find this list of definitions?
    Pg 76 post 1504
    Offline

    2
    ReputationRep:
    (Original post by Jimmy20002012)
    How is hclc=chcl e/z isomerism as they are the same group of atoms on each carbon?


    Posted from TSR Mobile
    each carbon has 1 hydrogen and 1 cl atom. definition of e/z is when each carbon is bonded to 2 different atoms.
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by needtosucceed=))
    each carbon has 1 hydrogen and 1 cl atom. definition of e/z is when each carbon is bonded to 2 different atoms.
    Ohhh okay, thanks for that how many exams you got next week then?


    Posted from TSR Mobile
    Offline

    2
    ReputationRep:
    (Original post by Jimmy20002012)
    Ohhh okay, thanks for that how many exams you got next week then?


    Posted from TSR Mobile
    its alright i've got 3, 2 on tuesday then 1 on thursday..you?
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by needtosucceed=))
    its alright i've got 3, 2 on tuesday then 1 on thursday..you?
    I have got 2 to tomorrow and then one everyday till Thursday


    Posted from TSR Mobile
    Offline

    2
    ReputationRep:
    (Original post by Jimmy20002012)
    I have got 2 to tomorrow and then one everyday till Thursday


    Posted from TSR Mobile
    ah that sucks what have u got tomorrow?
    Offline

    0
    ReputationRep:
    (Original post by Jonma)
    Can someone please explain this question?
    Attachment 222310
    Not sure if I'll be good at explaining this: you need to cancel out anything you have on both sides of the equations in the diagrams, then it will be one of the equations in the table so you put in the correspond enthalpy change. So for the bottom equation for example; you have CaCl2 and H2O on both sides so you can cancel them out and you're left with C + O2 --> CO2 which is the top equation in the table so for that oone in the diagram the enthalpy change is -393,, does that make sense? And then you add them up using Hess's law
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by needtosucceed=))
    ah that sucks what have u got tomorrow?
    Biology and IT


    Posted from TSR Mobile
    Offline

    0
    ReputationRep:
    Can someone please explain Q3bii on January 2012.
    It's the question about enthalpy of formation where they've drawn a cycle and you have to fill in the boxes.
    I got the top 3 correct, but I don't get the rest.
    Thanks
    Offline

    0
    ReputationRep:
    Hey could someone possibly explain how to do june 10 question 6 (c)(i)?
    Offline

    2
    ReputationRep:
    (Original post by Gotzz)
    Can someone please explain Q3bii on January 2012.
    It's the question about enthalpy of formation where they've drawn a cycle and you have to fill in the boxes.
    I got the top 3 correct, but I don't get the rest.
    Thanks
    if you've got 3 of them correct theres only 1 box left so just use the value you havent used yet?
    Offline

    0
    ReputationRep:
    Hi guys, there a question on the June 2009 Paper namely, 2c (ii) where it asks us to write the state symbols for an equation.
    The equation is 6C + 7H2 --> C6H14 (Hexane)
    Another piece of information we were given was that Hexane melts at -95 degrees Celsius and boils at 65 degrees Celsius

    Now Carbon is a solid in its standard state and hydrogen is a gas but how exactly are we supposed to know that Hexane is a liquid?
    Is that just something we should know or am I missing something :s
    Thanks
    Offline

    0
    ReputationRep:
    (Original post by Polypocus)
    Hi guys, there a question on the June 2009 Paper namely, 2c (ii) where it asks us to write the state symbols for an equation.
    The equation is 6C + 7H2 --> C6H14 (Hexane)
    Another piece of information we were given was that Hexane melts at -95 degrees Celsius and boils at 65 degrees Celsius

    Now Carbon is a solid in its standard state and hydrogen is a gas but how exactly are we supposed to know that Hexane is a liquid?
    Is that just something we should know or am I missing something :s
    Thanks
    I'm not sure but I think its because hexane is a component of crude oil which is a liquid?
    Offline

    2
    ReputationRep:
    (Original post by Polypocus)
    Hi guys, there a question on the June 2009 Paper namely, 2c (ii) where it asks us to write the state symbols for an equation.
    The equation is 6C + 7H2 --> C6H14 (Hexane)
    Another piece of information we were given was that Hexane melts at -95 degrees Celsius and boils at 65 degrees Celsius

    Now Carbon is a solid in its standard state and hydrogen is a gas but how exactly are we supposed to know that Hexane is a liquid?
    Is that just something we should know or am I missing something :s
    Thanks
    standard conditions are 25 degrees right, so if it boils 65, this temperature and above its a gas. it'll melt at -95 and anything above that. ie any value between -95 and 64 (as it boils at 65) therefore at 25degrees it would be melted and therefore a liquid. make sense?
 
 
 
Poll
Which web browser do you use?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Quick reply
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.