Hey there! Sign in to join this conversationNew here? Join for free
x Turn on thread page Beta

OCR A2 CHEMISTRY F324 and F325- 14th and 22nd June 2016- OFFICIAL THREAD watch

    Offline

    1
    ReputationRep:
    (Original post by alow)
    I assigned them all when I did F324.
    It's not necessary and doesn't feature in any F324 mark schemes.
    Offline

    19
    ReputationRep:
    (Original post by itsConnor_)
    https://gyazo.com/4466d9845c0fed137c580d4085972d86

    how are they "fairly distinct and assignable" ?
    Looks like a doublet on the RHS, a triplet slightly left of centre and something else overlapped with them.
    Offline

    19
    ReputationRep:
    (Original post by Chem1stry101)
    It's not necessary and doesn't feature in any F324 mark schemes.
    I never said it did, but it is correct.
    Offline

    11
    ReputationRep:
    (Original post by alow)
    Looks like a doublet on the RHS, a triplet slightly left of centre and something else overlapped with them.
    If you want to show off, please do it elsewhere because I am getting seriously stressed out now!
    Offline

    1
    ReputationRep:
    (Original post by itsConnor_)
    https://gyazo.com/4466d9845c0fed137c580d4085972d86

    how are they "fairly distinct and assignable" ?
    They're not. And any F324 mark scheme will just expect to state 5H on a benzene ring
    Offline

    10
    ReputationRep:
    (Original post by alow)
    I don't know if I was taught it but I did it, because it's the correct way.
    so for this compound here,

    the aromatic proton splitting would be doublets for 10,11,4,5 each with 1H and singlet for 2 with 1H.
    Offline

    11
    ReputationRep:
    (Original post by Chem1stry101)
    They're not. And any F324 mark scheme will just expect to state 5H on a benzene ring
    Thank you. Going to need to check things with my teacher tomorrow as alow has given me a panic attack!
    Offline

    1
    ReputationRep:
    (Original post by lai812matthew)
    so for this compound here,

    the aromatic proton splitting would be triplet, triplet, triplet, triplet and singlet??
    H on C2 would be a singlet

    H on C4 - a doublet

    H on C5 - a doublet

    H on C10 a doublet

    H on C11 a doublet

    But unlikely you would see these! It was integrated as 7H on the spectrum in the 2015 paper
    Offline

    10
    ReputationRep:
    (Original post by Chem1stry101)
    H on C2 would be a singlet

    H on C4 - a doublet

    H on C5 - a doublet

    H on C10 a doublet

    H on C11 a doublet

    But unlikely you would see these! It was integrated as 7H on the spectrum in the 2015 paper
    yeah realise i got in wrong edited it already.
    Offline

    1
    ReputationRep:
    (Original post by itsConnor_)
    Thank you. Going to need to check things with my teacher tomorrow as alow has given me a panic attack!
    I think alow is doing a Chemistry degree!
    Offline

    0
    ReputationRep:
    (Original post by anndz3007)
    has anyone got the markscheme for f324 june 15 ???
    https://www.dropbox.com/sh/kwj0elokp...S-r2mI-Pa?dl=0
    Offline

    15
    ReputationRep:
    (Original post by itsConnor_)
    Sorry but please don't stress me out the night before the exam unnecessarily...in proton NMR for benzene rings we only look at one splitting pattern right......?
    yo for benzene rings they have some crazy splitting just identify that its a benzene peak and state integration value, dont interpret the splitting.
    Offline

    1
    ReputationRep:
    (Original post by lai812matthew)
    yeah realise i got in wrong edited it already.
    You're a faster typer than me!
    Offline

    10
    ReputationRep:
    (Original post by Chem1stry101)
    You're a faster typer than me!
    i use computer in exams......
    Offline

    19
    ReputationRep:
    (Original post by itsConnor_)
    If you want to show off, please do it elsewhere because I am getting seriously stressed out now!
    Calm down dear. There's nothing wrong with learning a bit more chemistry.

    (Original post by lai812matthew)
    so for this compound here,

    the aromatic proton splitting would be triplet, triplet, triplet, triplet and singlet??
    For aromatic systems there is usually coupling between "neighbouring protons" with a relatively large splitting, and then coupling across the ring with smaller splitting (this is not always seen if the NMR is not taken at high enough resolution).

    For that I would say:

    2- Singlet (nothing close)
    4- Doublet (couples with 5)
    5- Doublet (couples with 4)

    (these may display cross-ring coupling to make 2 a doublet and 4/5 doublets of doublets).

    10- Doublet (couples with 11)
    11- Doublet (couples with 10)

    (these may also be doublets of doublets due to small cross-ring coupling).
    Offline

    1
    ReputationRep:
    The only useful spitting pattern you might see is 2 doublets for benzene with an integration of 4, which indicates a 1,4 substituted benzene ring.
    Offline

    10
    ReputationRep:
    (Original post by Chem1stry101)
    I think alow is doing a Chemistry degree!
    check his profile, saw him at cambridge threads before
    Offline

    5
    ReputationRep:
    (Original post by Chem1stry101)
    H on C2 would be a singlet

    H on C4 - a doublet

    H on C5 - a doublet

    H on C10 a doublet

    H on C11 a doublet

    But unlikely you would see these! It was integrated as 7H on the spectrum in the 2015 paper
    Wouldn't the peaks for C11 and C10 both be triplets? Because there are 2 H in each environment and both are adjacent to a H?
    Offline

    1
    ReputationRep:
    (Original post by lai812matthew)
    i use computer in exams......
    I'm typing on my phone so slow!
    Offline

    3
    ReputationRep:
    Guys question!! For proton NMR, can the H in the aldehyde group be split?? Cos I've heard from certain sources that it always remains as a singlet, but the last question on the June 2014 paper seems to suggest otherwise??

    Thank you!
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: September 26, 2016
Poll
Do you agree with the proposed ban on plastic straws and cotton buds?

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

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