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    Can someone please explain how to draw polydentate complex ions?? such as EDTA
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    (Original post by MrPolish)
    did you resat biol unit 4 as well ? i really liked that paper compared to last years biology
    sorry what?? I was so time constrained and the questions were alright I guess but there was not much time to expand on points and elaborate on them. And nah last years biology had proper biology with immune system, dna profiling,photosynthesis not death, global warming and carbon cycle, GPP/NPP which are my weakest topics
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    (Original post by plshelpmylife)
    Can someone please explain how to draw polydentate complex ions?? such as EDTA
    You'll never need to learn to draw that, well according to my chem teacher last year
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    (Original post by Anonymous696061)
    Hello, this isn't complete, but this is just some generic answers I've made to some common Q's I've seen creep up -I just thought it might help some people struggling with revision! -Good luck!
    Hi thanks for this. Just noticed a small error so I thought it would be best to let you know. When discussing the electrode potentials, you have got it the wrong way round. It is the more negative standard electrode potential that is the stronger reducing agent, not the oxidising agent. The one with the more positive electrode potential is reduced and so is the stronger oxidising agent.
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    Can someone explain to me why the formula of the complex ion in june 2014 Q1 (d)(ii) is (Fe(C6H507))-??
    don't get the negative 1
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    (Original post by BrokenS0ulz)
    Hi thanks for this. Just noticed a small error so I thought it would be best to let you know. When discussing the electrode potentials, you have got it the wrong way round. It is the more negative standard electrode potential that is the stronger reducing agent, not the oxidising agent. The one with the more positive electrode potential is reduced and so is the stronger oxidising agent.
    Aaaahhh, thank you so much, I didn't even spot that!! -Will try & post a revised version if there's time! -Thanks again!!
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    (Original post by chococup123)
    Can someone explain to me why the formula of the complex ion in june 2014 Q1 (d)(ii) is (Fe(C6H507))-??
    don't get the negative 1
    The Fe is 2+ and the overall charge for C6H5O7 is said to be -3, so if you add them together you get a charge of -1
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    (Original post by MathsAddict)
    LOOOOOOL F334 June 2014 is total bull**** so many tricks. They really hated that year group xD
    That paper is the reason I am doing a third year lmfao

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    (Original post by MrPolish)
    The Fe is 2+ and the overall charge for C6H5O7 is said to be -3, so if you add them together you get a charge of -1
    oh it's just that. I was complicating things haha
    thank youu!!
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    When you draw the electrons in the sub shells do you draw all the arrows up in both the 4s and 3d sub shell OR do you draw the two electrons in the 4s sub shell and then fill the 3d sub shell first going one direction and then the other...if that makes sense?
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    (Original post by radhikagulati)
    When you draw the electrons in the sub shells do you draw all the arrows up in both the 4s and 3d sub shell OR do you draw the two electrons in the 4s sub shell and then fill the 3d sub shell first going one direction and then the other...if that makes sense?
    4s fills up first, apart from Cr and Cu, but yeah you first draw both arrows in 4s and then in the 3d block, if that makes sense
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    (Original post by MrPolish)
    4s fills up first, apart from Cr and Cu, but yeah you first draw both arrows in 4s and then in the 3d block, if that makes sense
    Thank you so much! I was so confused! x
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    (Original post by anni101)
    You'll never need to learn to draw that, well according to my chem teacher last year
    it's definitely come up in some papers i've been doing! EDTA seems to be a popular choice
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    (Original post by plshelpmylife)
    it's definitely come up in some papers i've been doing! EDTA seems to be a popular choice
    in the revision guide it says its an example you need to know about.
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    could i have help with the last part of this q
    i thought the rate of formation = rate of disappearance but apparently it is not :/
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    June 2009 , 5)d ) any idea why PCL cant form hydrogen bonds between chains as the O on the ends of the molecules will have a lone pair right?
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    (Original post by docdoc02)
    could i have help with the last part of this q
    i thought the rate of formation = rate of disappearance but apparently it is not :/
    Dont know what paper but isnt it first order with respect to I-? so it wouldnt be the same as rate of formation of iodine? Not sure,
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    (Original post by suyoof123)
    June 2009 , 5)d ) any idea why PCL cant form hydrogen bonds between chains as the O on the ends of the molecules will have a lone pair right?
    There are no delta positive atoms in line with them to form H bonds.
    As a general rule you should just remember that:
    Polyester polymer chains= pd-pd
    Polyamide polymer chains= H bonds
    and then for polymers like poly(ethene) they'll have id-id
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    I'm sitting this exam tomorrow!!
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    Dear Ocr salters B,
    I know I've said that I hate you many,many times over the past 2 years
    And that I wish I was doing Ocr A instead
    I didn't meant any of that
    Please be nice tomorrow (and I mean actually nice, not 'salters nice').
    Thanks

    On another note...can someone explain naming amines to me please!
    Because sometimes it's 'x'-yl amine, and other times it is -amino-'x'
 
 
 
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