Turn on thread page Beta

Edexcel A2 Chemistry Exams -6CH04 (14th June) and 6CH05 (22nd June) Discussion Thread watch

    Offline

    2
    ReputationRep:
    (Original post by C0balt)
    You should get the mark

    That's right
    12.5 ans 37. 5 is half neutralisation point where pH=pKa
    25 and 50 is right or 12 and 37.5?
    Offline

    14
    ReputationRep:
    (Original post by Tomasio)
    25 and 50 is right or 12 and 37.5?
    25 and 50 are the equivalence points/vertical sections
    Offline

    2
    ReputationRep:
    (Original post by C0balt)
    25 and 50 are the equivalence points/vertical sections
    yeah, agreed that the vertical sections are at 25 and 50. pka is not 12.5, 37.5?
    Offline

    2
    ReputationRep:
    It was harder overall I thought...
    Offline

    14
    ReputationRep:
    (Original post by Tomasio)
    yeah, agreed that the vertical sections are at 25 and 50. pka is not 12.5, 37.5?
    pKa are same as pH at half neutralisation points ie at 12.5 and 37.5 indeed
    Offline

    2
    ReputationRep:
    (Original post by C0balt)
    pKa are same as pH at half neutralisation points ie at 12.5 and 37.5 indeed
    omds cheers
    I got a mark
    Offline

    1
    ReputationRep:
    I think it was the third multiple choice or so, but the question was about 2 mechanisms. Were the answers: bond broken bond formed, racemic mixture ?
    Offline

    5
    ReputationRep:
    (Original post by shazza.kk)
    I think it was the third multiple choice or so, but the question was about 2 mechanisms. Were the answers: bond broken bond formed, racemic mixture ?
    Bonds broken


    Posted from TSR Mobile
    Offline

    0
    ReputationRep:
    (Original post by C0balt)
    pKa are same as pH at half neutralisation points ie at 12.5 and 37.5 indeed
    Being super harsh, I think I got 76 at worst.. Do you think this will be an A* 🙏🏻
    Offline

    14
    ReputationRep:
    (Original post by Tomasio)
    omds cheers
    I got a mark
    Yay
    (Original post by shazza.kk)
    I think it was the third multiple choice or so, but the question was about 2 mechanisms. Were the answers: bond broken bond formed, racemic mixture ?
    Iirc i think so
    (Original post by Hdb)
    Being super harsh, I think I got 76 at worst.. Do you think this will be an A* 🙏🏻
    Should be
    Offline

    2
    ReputationRep:
    (Original post by C0balt)
    pKa are same as pH at half neutralisation points ie at 12.5 and 37.5 indeed
    Oh I said pka=ph at the first equivalence point/neutralisation :/ btw did you have a clear vertical section for the first equivalence point? I found it difficult cos the starting ph (1.5) and ph of the first neutralisation (1.9) were too close


    Posted from TSR Mobile
    Offline

    14
    ReputationRep:
    (Original post by sayshay)
    Oh I said pka=ph at the first equivalence point/neutralisation :/ btw did you have a clear vertical section for the first equivalence point? I found it difficult cos the starting ph (1.5) and ph of the first neutralisation (1.9) were too close


    Posted from TSR Mobile
    Well if you think about it
    Ka=[H+][A-]/[HA] and at half neutralisation [A-] =[HA] so the fraction cancels and you get Ka=[H+] so pKa=pH at half neutralisation.
    I did, I don't think it was too difficult because it was supposed to be a really gradual rise anyway due to buffer effect
    Offline

    1
    ReputationRep:
    (Original post by chemica)
    Do you unit 4 is harder than unit 5 ? swear down last years unit 5 was piss easy
    I got the grade boundaries wrong we're not IAL so its more like 70 for an A i reckon :'( personally unit 4 vs 5 neither is more difficult just depends on the year.
    Offline

    9
    ReputationRep:
    (Original post by Hdb)
    Being super harsh, I think I got 76 at worst.. Do you think this will be an A* 🙏🏻
    Wish I was in a position where 76 was my worst case scenario lol...
    Offline

    2
    ReputationRep:
    lads , that multiple chooice question when it was like only one of the mechanisms does this . Was it forms a racemic mixture or was it the one about only one of them leads to elimination . For the tms one i put there are many (12 ) hydrogens , i didnt say they were in the same environment. Would i lose the mark?
    Offline

    1
    ReputationRep:
    (Original post by Hdb)
    Being super harsh, I think I got 76 at worst.. Do you think this will be an A* 🙏🏻
    Think it was 78 last year so seeing as response has been less positive you're probably gonna be very close, just need to do well in Unit 5 too
    Offline

    1
    ReputationRep:
    What was the pH question about H2S I can't remember it for the life of me?
    Offline

    0
    ReputationRep:
    (Original post by Science&Despair)
    Think it was 78 last year so seeing as response has been less positive you're probably gonna be very close, just need to do well in Unit 5 too
    Thanks bro, really need to do well in unit 5 since I've only scraped an A* in practical too :/
    Offline

    8
    ReputationRep:
    I made so many stupid mistakes
    Offline

    2
    ReputationRep:
    you know for that question about what is bad in the equilibrium with barium chloride, could you have said the ammonia because it is toxic
 
 
 
Poll
Cats or dogs?

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.