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    (Original post by smithy55)
    hi what did everyone get for the q=mcdt question, i got 503k

    also on the last question i got a 2:1 ratio, how did people get 3:1?
    I got 2:1 on experimental and 4:1 on theoretical
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    (Original post by ImaNeek)
    Didn't you use the AQA official book for chemistry? Moreover it said you need to know and understand ▲E=hV
    No I only had my class notes to revise off
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    (Original post by smithy55)
    yeah i thought 503 was a bit big but i didn't know what to use for q
    I did the enthalpy of solution multiplied by the number on moles to get Q
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    (Original post by TommehBoi)
    **** off
    Sorry
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    Where are questions 2 and 3 on the thread Id like to help complete the mark scheme
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    (Original post by godjohnson)
    Cant you just put up the whole paper??
    I have put up the whole paper - my problem was I could't see which pages I hadn't uploaded
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    so judging from peoples responses this exam should have a grade boundary of like 70/71 for an A
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    (Original post by Joshalos)
    For question 4e it was the reaction of phosphorous oxide with NaOH not MgO .
    true dat i wrote 6NaOH+ P2O5--------->2Na3(PO4) +3H2O
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    (Original post by SexyAndIKnowIt.)
    Ok. Looking at that mark scheme and all of the previous year's grade boundaries, I have got a D when I was aiming for an A. Completely messed up that exam. So angry with myself. How was I supposed to know the unit of frequency. That's not general knowledge and Ive never been taught that. Grrrrrrrr
    Same :'( 52 based on the unofficial mark scheme! I did something stupid on every calculation question, mucked up a few equations plus got some of the explainy ones wrong
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    (Original post by qwerty1D)
    i put cocl3nh3 but i put a negative charge because technically that would be the charge but then that makes in an ion so i'm unsure, but if cocl2nh3 is neutral cocl3nh3 is -1? any thoughts mate?
    See I didn't notice the part where it formed a solid, so I didn't have any bones about putting the charge. However knowing it was a solid, I am a bit confused by the whole question.

    The ratio was 3:1 definitely, but with nitrogen, chlorine, cobalt and hydrogen only, I don't see how you can make it not having a charge :-/ im just praying for low boundaries.
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    (Original post by cuckoo99)
    true dat i wrote 6NaOH+ P2O5--------->2Na3(PO4) +3H2O
    I put P4O10 + 12NaOH --> 4Na3PO4 + 6H2O. Remember, Phosphorus(v) oxide is P4O10.
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    (Original post by Jesss9)
    Same :'( 52 based on the unofficial mark scheme! I did something stupid on every calculation question, mucked up a few equations plus got some of the explainy ones wrong
    I know how u feel but remember the unoffical MS is missing two questions. I needed a high B to get my overall A and i dont think i've got it
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    Can someone please show their working out for 1d. Ididnt get th answer in th unoffical MS and i still dont understand where i've went wrong.
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    (Original post by Jessica-F)
    I know how u feel but remember the unoffical MS is missing two questions. I needed a high B to get my overall A and i dont think i've got it
    What two question's are missing? I don't know what I need for an A because I retook chem 2 and 4 but if they went well I can still get an A with a bad chem 5 mark! (fingers crossed) Hopefully grade boundaries will be really low or the mark scheme particularly nice and we can still get what we need!
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    (Original post by Dalts)
    Well no because its asking about lattice dissociation, which is endothermic, so would increase, and no because the additional strength of covalent character with the ionic lattice means there needs to be more energy to overcome these forces, the only exception of this rule however, for a very complicated reason is Al2O3
    look in the textbook i'm right, more endothermic then
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    (Original post by AspiringGenius)
    See I didn't notice the part where it formed a solid, so I didn't have any bones about putting the charge. However knowing it was a solid, I am a bit confused by the whole question.

    The ratio was 3:1 definitely, but with nitrogen, chlorine, cobalt and hydrogen only, I don't see how you can make it not having a charge :-/ im just praying for low boundaries.
    It said it was prepared with an oxidising agent so I think the Co2+ was oxidised to Co3+ so there was 3 Cl- in the complex to form a ppt? I'm really unsure about the complex though, I rushed this one
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    This paper was very tricky no doubt, and not all the questions were accessible to all candidates. Let's take an example, the 2 marker on the y=mx+c, which is although seen as simple, is a maths derived question with Math students having an advantage over those who don't even study it at A level. I forgot all that stuff from GCSE but yes I understand it was an application based Q but still y=mx+c isn't exactly on the spec. Also at college, we were told derivation of delta G was not required.

    Also the synoptic 5 marker was a bummer. The last question was difficult
    and I haven't seen a Q like that before either - although some people found it ok.

    A paper which is normally accessible to all candidates was turned upside down and its fair to say CHEM5 could have potentially caused a majority of us to slip up by a grade due to their inability to ask bloody straight forward Q's, so annoyed... Like the majority 😠


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    (Original post by Dalts)
    Well no because its asking about lattice dissociation, which is endothermic, so would increase, and no because the additional strength of covalent character with the ionic lattice means there needs to be more energy to overcome these forces, the only exception of this rule however, for a very complicated reason is Al2O3
    http://www.chemguide.co.uk/physical/...s/lattice.html
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    (Original post by fowlerbean)
    It said it was prepared with an oxidising agent so I think the Co2+ was oxidised to Co3+ so there was 3 Cl- in the complex to form a ppt? I'm really unsure about the complex though, I rushed this one
    Ahhh. that makes sense, i didnt really give much thought to the oxidising agent. so the complex would have been... CoCl3(NH3)3?
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    (Original post by RoaringLion)
    This paper was very tricky no doubt, and not all the questions were accessible to all candidates. Let's take an example, the 2 marker on the y=mx+c, which is although seen as simple, is a maths derived question with Math students having an advantage over those who don't even study it at A level. I forgot all that stuff from GCSE but yes I understand it was an application based Q but still y=mx+c isn't exactly on the spec. Also at college, we were told derivation of delta G was not required.

    Also the synoptic 5 marker was a bummer. The last question was difficult
    and I haven't seen a Q like that before either - although some people found it ok.

    A paper which is normally accessible to all candidates was turned upside down and its fair to say CHEM5 could have potentially caused a majority of us to slip up by a grade due to their inability to ask bloody straight forward Q's, so annoyed... Like the majority ��


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    I can speak as a non-Maths student, and that graph question was awful. I understand that y=mc+c for a straight line, but I had and have no idea how to interpret it for a delta G equation.
 
 
 
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