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    Anyone sit this one today? I didn't like it. Found I was writing to the end, and, urgh. But some was alright. How did others find it?
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    Yeah i sat it.
    Mixed feelings about it...
    Although some parts were easy, others were tricky - I didnt like the polymer question and wasnt sure of my answer for the polymer comparisons (3/4 marks i think). I also drew the polymer repeating unit wrong.
    I had a feeling the recrystalisation question (5marks) would come up, and also had a feeling a question on Rust would come up - revised this in the morning!
    Can you remember any answers you put. Unsure of any?
    Will just have to wait for the results now...
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    I also have mixed feelings. I am uncomfortable with around 30 marks worth.

    I was uncomfortable with all the questions about analysis, and I remember putting brown for the colour of Iron 3, as I thought that was right, and it turns purple in the presence of a phenol group, but some friends objected.

    I additionally wasnt sure about the question where it asked about the ions that would form when HCl was added. A friend made it an acyl chloride, but I made it a Cl- ion and some other thingy...

    In the spectroscopy we all got a carboxylic acid as the group, but disagreed on what X was... My friend and I drew the left side of the molecule, with the COOH group instead of the ester group, whereas another friend drew ethanoic acid I believe... Both had an Mr of 60

    Any ideas anyone?

    And the thing about rust and the changes to its physical properties... that was TOO random...
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    I too got COOH for the spectroscopy, for X i think i did CH3-COOH ? i wasnt sure so just put anything in.

    The Iron(III)cholride...i got the first 2 boxes wrong - didnt know the colour - but the 3rd box should be purple.

    WHat about the polymer question where it said why is the polymer brittle?
    what did you say about that (for 3 marks/4marks worth)?
    At beginnine of polymer question it said condensation/polymersation - i put condensation = joining of the 2 monomers/molecules with elmination of small molecule of h20 (as question diagram showed h20)
    and i put polymersation as joiining of monamers into chain repeatidly or seomthing like that...

    Also, did you put octahedral for the ligand...
    erm, and a
    It was a werid paper, and i too think if i have done badly i have lost around 30 marks. If any luck, and ive done alright, around 18-20 marks lost.
    I really wanted to score a good grade like 85% +
    But oh well.
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    Right I'll try to remember some of the stuff I put:

    I somehow got 3 different H environments for the nmr question, but my friends seem to have put only 2 in. I did the OH, CH2 and CH3.

    Ah - the repeating unit for the 2 monomers, would've been easier if they didn't give the skeletal formula. That dodgy one with OH at both ends, I hope that had only 4 carbons in it, rather than 6. I hate skelatal formula!

    I'm glad about the recrystalisation one as I revised that but everyone was annoyed colorimetry didn't show because I learnt that fully.

    Please, someone tell me what the colour of iron (III) chloride is! I can't find it anywhere, all my revision guides just state that it turns purple with a phenol, but not what it is beforehand. I made a guess as it being colourless, which looking back, wasn't a very good idea.

    When the HCL was added I put the H on the NH2 --> NH3+ and a Cl- ion. This was the on the amino acid right? As I'm not sure how that could turn into an acyl chloride.

    I hated the question on IR spec. It just took me ages to interpret. I ran out of time before I could draw the molecule but I thought it was ethanoic acid looking back.

    I also hated (I hated alot of this paper) that rust question. I actually had no idea how to change the properties so I took a guess and put 'make it less brittle'. I thought it was better to write something than nothing.

    Hmmm what else... ah yeh the equilibrium constant was tricky - Only because you had to put double []'s round everything (complex and concentration)

    I wasn't sure the direction of electron flow, I just put from A - B and also was unsure of why that equation ( I fogot what exactly) only happens at A.

    The most annoying thing is that it took me ages to complete, and didn't have time to go over everything lots like usual, but never mind. Now need to wait til March.
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    Octahedral yep...

    I seem to have dealt with the polymers quite well...

    Its brittle due to beinmg below its Tg, glass transition temperature. Below this temp, the amorphous coils and chains are frozen in position and the bonds have no way to give, other than breaking. So when you attempt to flex the polymer it will break, due to the inerlocking frozen chains.

    The next answer involved mentioned copolymerisation and plasticisers as ways of lower the glass transition temperature...
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    (Original post by cherc2005)
    WHat about the polymer question where it said why is the polymer brittle?
    what did you say about that (for 3 marks/4marks worth)?
    Also, did you put octahedral for the ligand...
    erm, and a
    It was a werid paper, and i too think if i have done badly i have lost around 30 marks. If any luck, and ive done alright, around 18-20 marks lost.
    I really wanted to score a good grade like 85% +
    But oh well.
    I put for the brittle polymer that at low temperatures it is below its glass transition temperature, and that there are many amorphous areas, so less IM forces and easier to snap (absolutley no idea if thats right or not).
    I put octahedral for the ligand.
    I too think a loss of 30 marks is possible. Well retake is 23rd June!
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    Ramaya you seem to be right on the NMR, most of my class got three environments... tho I think I messed up some of it as it didnt appear right in the table... got the first to be a phenol and be between 4.5 and 10... Almost certain that Iron III Chloride is ORANGEY BROWN, since I did my practical epxeriment with it, and it turned purple with phenols...

    I also didnt know how an acyl chloride could be made, and did the same as you getting a Cl- and an NH3+ thingy on the rest of it... not sure if its right, but hey!

    At least there was nothing beyond 2 marks that I couldnt do at all, and so I havent lost like 10 on one question or something mad... Hope I do alright on it, I worked quite hard for the exam..
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    Ah never mind, Iron (III) Chloride makes sense to be brown really!
    Ooh i know there were 2 calculations - but all I know is I got 70-something% and then 0.088? SOmthing around that. I am pretty bad with calculations.
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    Seems you did okay to me
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    (Original post by RobbieC)
    Seems you did okay to me
    March seems ages away though.
 
 
 

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