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    (Original post by zirak46)
    Oh great. Pls f325 dont be hard.
    Hahaha hopefully they'll be nice this year seeing as its the last exams of this spec I think...
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    (Original post by Heisenberg___)
    Hahaha hopefully they'll be nice this year seeing as its the last exams of this spec I think...
    I would have thought that's all the reason not to be nice this year. Ah well, we'll find out soon I guess...
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    (Original post by Heisenberg___)
    How is everyone feeling about the two exams?? After last years papers, I reckon f324 will be slightly easier and f325 marginally harder
    I'm worried a massive NMR question on F324 and a horrendous redox titration question on F325 will trip me up :cry2:
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    (Original post by Kamara7)
    I'm worried a massive NMR question on F324 and a horrendous redox titration question on F325 will trip me up :cry2:
    They are literally the worst type of question in each paper!!!

    For NMR questions, I just always state the chemical environments, number of protons/carbon atoms in that environment and number of adjacent protons - that always seems to pick up loads of the marks! But I'm really worried that I'll just panic under the pressure
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    I've attached part of F325 June 2013 Question 8. Please can someone explain to me the last part? I've correctly solved some of it, but I don't understand the rest. Thanks!
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    someone pls tell me what t.m colours we need to know, i learn the ones given but then i find out there r more, its endless!


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    Purple green pink green brown purple green blue

    All respective to

    Ti, Cr, Mn, Fe 2+, Fe3+, Co, Ni, Cu

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    Hey can someone please explain two things from this question:

    1) how to know which acid with pka would have ph 3.55

    2) what does it mean by relative concentrations? How would the final answer be written?

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    (Original post by Heisenberg___)
    They are literally the worst type of question in each paper!!!

    For NMR questions, I just always state the chemical environments, number of protons/carbon atoms in that environment and number of adjacent protons - that always seems to pick up loads of the marks! But I'm really worried that I'll just panic under the pressure
    This is exactly what I do! It's just annoying that I can't get the last 1 or 2 marks for the structure as I usually don't have enough time I don't like the titration ones as well because they give you a page to read then there's a question saying "find the mass of X" or something for 6 or more marks :eek: They give you tons of blank space and I just look at it like:

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    Scared of a2 chemistry exams the most.

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    (Original post by Hunnybeebee)
    Scared of a2 chemistry exams the most.

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    You're not the only one :/


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    Anyone got tips on how to do and answer nmr questions? (Ocr)

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    guys difference between polypeptides and polyamides? besides the linkage what else i different really, its just the same thing reacting together so how come one produces a polypeptide and another an amide linkage?


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    (Original post by ranz)
    guys difference between polypeptides and polyamides? besides the linkage what else i different really, its just the same thing reacting together so how come one produces a polypeptide and another an amide linkage?


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    Polypeptides are just a type of polyamide - but polypeptides are specifically made of amino acids.
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    (Original post by ranz)
    guys difference between polypeptides and polyamides? besides the linkage what else i different really, its just the same thing reacting together so how come one produces a polypeptide and another an amide linkage?


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    Aren't they the same thing? I thought a peptide bond is an amide bond. Polyamide is an umbrella term which polypeptide comes under, I think polypeptide specifically refers to a polymer of amino acids
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    (Original post by med456)
    Does anyone have the f325 2015 past paper & mark scheme? I really need it for revision!
    Did you find them?
    Pls send pm 😅


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    Please anyone send me 2015 papers f321 f322 f324 f325
    I'm external so can't ask teacher and I've finished all of the others 😭😭
    Pls help me and God will bless you and give you good results


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    (Original post by Kamara7)
    Aren't they the same thing? I thought a peptide bond is an amide bond. Polyamide is an umbrella term which polypeptide comes under, I think polypeptide specifically refers to a polymer of amino acids
    Can't polyamides be made from a carboxylic acid and an amine? Whereas polypeptides are made from lots of amino acids specifically, not lots of carboxylic acids and amines.
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    Why does the equilibrium of a weak acid lie well to the left ie

    CH3COOH <---> H+ CH3COO-

    I thought it's because there's less moles on the left but my book says that there's a small conc of dissociated ions compared to the conc of undissociated?

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    (Original post by Hunnybeebee)
    Why does the equilibrium of a weak acid lie well to the left ie

    CH3COOH <---> H+ CH3COO-

    I thought it's because there's less moles on the left but my book says that there's a small conc of dissociated ions compared to the conc of undissociated?

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    In weak acids, eq lies more to left due to PARTIAL dissociation.

    If not everything dissociated (partial), then obvs equilibirium will be more to left

    Get me?
 
 
 
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