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    (Original post by Al_YG)
    There was an even quicker way which was to see the huge increase in temp for D and compare it with B's answer for one mole...lol D was the answer therefore.. what about the second to last. Sorry for bragging but no-one has answered all 15 multiple choices (only the first 12).
    Honestly i finished with like 15 minutes left (which i was amazed at because in the first paper i had 2 minutes left) so i just went through all of the questions, double checking them properly. And can you remember what the last question was?
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    (Original post by Splaffie)
    it was propanal propan-1-ol and butane
    yeah but the question they are talking about only asked to distinguish between the first two molecules not all three
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    (Original post by Splaffie)
    d was a decrease of 0.5 moles
    ...this is a very awkward situation. If anyone else can speak to tell us whether it was an increase or decrease please let us know.
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    (Original post by marcobruni98)
    Propanal and propanol are not isomers
    forgot the double bond, yeah it was prop-2-en-1-ol and propanal, which have structural isomerism
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    (Original post by marcobruni98)
    Propanal and propanol are not isomers
    Yeah it was definitely propanal and propan-2-en-1-ol because i remember the name and they're isomers
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    (Original post by Al_YG)
    ...this is a very awkward situation. If anyone else can speak to tell us whether it was an increase or decrease please let us know.
    it seems silly to have a 0.5 increase in both with an obvious temperature difference
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    what was the answer for the graph question, i levelled it off at the same place but was it steeper or shallower gradient?
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    (Original post by GabbytheGreek_48)
    yeah but the question they are talking about only asked to distinguish between the first two molecules not all three
    if thats true then thats even more marks i lost for idiocy
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    (Original post by Al_YG)
    ...this is a very awkward situation. If anyone else can speak to tell us whether it was an increase or decrease please let us know.
    From what i can remember, A and D caused and increase whereas B and C caused a decrease or no change, this might not help but y'know worth saying
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    (Original post by SURH)
    what was the answer for the graph question, i levelled it off at the same place but was it steeper or shallower gradient?
    Steeper and levelled off lower
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    (Original post by neon_reaper)
    Yeah it was definitely propanal and propan-2-en-1-ol because i remember the name and they're isomers
    So the answer can be that they are isomers so they have the same number of atoms of each element giving them equal Mr and as a result will have equal M/Z ratios on a mass spectrometer?
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    (Original post by Splaffie)
    if thats true then thats even more marks i lost for idiocy
    depends which question you are talking bout the one about distinguishing them you might not have because using the mr alone is the valid point if you say they are isomers then just a extra thing not really needed
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    (Original post by neon_reaper)
    Steeper and levelled off lower
    you sure? wouldn't it level off the same
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    (Original post by GabbytheGreek_48)
    depends which question you are talking bout the one about distinguishing them you might not have because using the mr alone is the valid point if you say they are isomers then just a extra thing not really needed
    its really annoying me how many mistakes i make when i can remember almost the entire specification off by heart but when i go through exams i just make mistakes everywhere where i know i shouldnt be
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    (Original post by marcobruni98)
    So the answer can be that they are isomers so they have the same number of atoms of each element giving them equal Mr and as a result will have equal M/Z ratios on a mass spectrometer?
    I did a very similar question on a past paper (got it wrong so i learnt the answer) and the answer on that was:
    They have the same molecular formula (1) and so would have the same relative molecular mass (1).
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    (Original post by SURH)
    you sure? wouldn't it level off the same
    No because there were fewer moles (conc x vol = mol, conc had increased and vol had decreased so just sub it in) so it would have to level off lower
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    (Original post by Splaffie)
    its really annoying me how many mistakes i make when i can remember almost the entire specification off by heart but when i go through exams i just make mistakes everywhere where i know i shouldnt be
    yeah ikr it sucks i countred through again and found all the stupid mistakes that could have been avoided dont worry though you seem really smart im sure you've gotten an A but yeah during exams your trying to complete stuff as fast as possible and we all tend to miss stuff especially me like with the hexane thing i know hexane has six carbons but in the exam i some how thought it had five and i lost a mark cus of that so dont worrry youll do well
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    (Original post by neon_reaper)
    No because there were fewer moles (conc x vol = mol, conc had increased and vol had decreased so just sub it in) so it would have to level off lower
    it was exactly 1 square lower because the molar ratio gave 88.888% and 88.88% of 9 is exactly 8
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    (Original post by Splaffie)
    it was exactly 1 square lower because the molar ratio gave 88.888% and 88.88% of 9 is exactly 8
    Yeah i did that but just because it seemed like a good place to draw it rather than calculating it (lucky as hell) not sure if they'll penalise you for not drawing it on the line because they didn't actually give units on the graph, but it wasn't hard to work out so
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    (Original post by neon_reaper)
    No because there were fewer moles (conc x vol = mol, conc had increased and vol had decreased so just sub it in) so it would have to level off lower
    what was on the y -axis of the graph?
 
 
 
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