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    (Original post by nicoleemmak)
    Would you not have done moles of the other thing x125 then worked out the mass from that
    That's what I'm saying!! What was your final mass you got 0.3 something right?? )
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    What did everyone write for the one about adding acid and alkali to shift the equilibrium??
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    (Original post by SlippyDuck117)
    I'm pretty sure I've seen this in a mark scheme, so 2/3 I'd say for sure.
    (Original post by mattyk5)
    yh i think you lose one mark for the "+"
    Thanks. What about the enthalpy change question, working out Hr, i knew i should have included the mass of magnesium as well, plus i didn't put the minus sign in the answer! how marks out of 4 do you think?
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    (Original post by mercuryman)
    That's what I'm saying!! What was your final mass you got 0.3 something right?? )
    I can't remember but probably If we did it the same way
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    Did anyone get something like 0.38 for the mass of mg? because m=0.0125x24.3 =0.303. And then you multiply that by 1.25 to add the 25% which gave 0.379 so 0.38 to 2dp??
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    (Original post by mercuryman)
    That's what I'm saying!! What was your final mass you got 0.3 something right?? )
    0.38 is what i got
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    (Original post by nicoleemmak)
    What did everyone write for the one about adding acid and alkali to shift the equilibrium??
    acid shifts to the right because increase H+ conc
    alkali shifts to the left because decreases H+ conc and increases (OH from water)


    But i think for the alkali i shouldve wrote about it JUST decreasing the H+ conc so the equilbruim moves to ITS side. idk why i mentioned water etc
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    1062 for the bond enthalpy of CO?
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    (Original post by bakedbeans247)
    Thanks. What about the enthalpy change question, working out Hr, i knew i should have included the mass of magnesium as well, plus i didn't put the minus sign in the answer! how marks out of 4 do you think?
    Although it varies from paper to paper, I've seen these sort of statements in mark schemes:
    1 mark for bonds broken, calculated correctly
    1 mark for bonds formed, calculated correctly
    1 mark for correct Hr
    1 mark for the correct sign

    So at least 1, probably 2 marks. Unless I'm thinking about the wrong enthalpy change question haha
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    (Original post by nicoleemmak)
    What did everyone write for the one about adding acid and alkali to shift the equilibrium??
    i wrote when acid added dere is an increase in conc. of h+ dere to minimise dis change equilibrium shifts right or and for alkali oh- increases therefore left
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    (Original post by SlippyDuck117)
    Although it varies from paper to paper, I've seen these sort of statements in mark schemes:
    1 mark for bonds broken, calculated correctly
    1 mark for bonds formed, calculated correctly
    1 mark for correct Hr
    1 mark for the correct sign
    thnks, what do you think the grade boundaries will be like? Also how many marks was the last question?
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    (Original post by bakedbeans247)
    thnks, what do you think the grade boundaries will be like? Also how many marks was the last question?
    I'm pretty sure the last question was 13 marks.

    I'm not sure about what the grade boundaries will be. Personally I reckon about 79-82 for an A, however that might be affected by the nature of the exam, i.e. only resit candidates took it.

    What does everyone else reckon an A would be?
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    (Original post by Pingu7)
    That's what I got because they gave enthalpy of combustion values in the table provided
    what did u guys got for bond enthalpy one?
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    (Original post by mercuryman)
    You work out the molecular formula straight away which was c3h7br , I'm pretty sure that's what I got
    0.38 should be correct, got that as well. Also for the mr I got 122.9 or something like that
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    I somehow got 30.8 grams for the magnesium.. somebody explain?
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    (Original post by SlippyDuck117)
    I'm pretty sure the last question was 13 marks.

    I'm not sure about what the grade boundaries will be. Personally I reckon about 79-82 for an A, however that might be affected by the nature of the exam, i.e. only resit candidates took it.

    What does everyone else reckon an A would be?
    86/100 for an A

    100/100 for max

    Therefore, losing around 9-10 marks would score you around 137 ums/150 ums
    Which in my opinion is decent
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    (Original post by SlippyDuck117)
    I'm pretty sure the last question was 13 marks.

    I'm not sure about what the grade boundaries will be. Personally I reckon about 79-82 for an A, however that might be affected by the nature of the exam, i.e. only resit candidates took it.

    What does everyone else reckon an A would be?
    Oh my! I totally forgot that bec it's only re-sitters it'll increase the grade boundaries, plus that paper was pretty is no? Daam...all i needed was a strong B and i flopped by running out of time and making silly mistakes.
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    (Original post by SlippyDuck117)
    I'm pretty sure the last question was 13 marks.

    I'm not sure about what the grade boundaries will be. Personally I reckon about 79-82 for an A, however that might be affected by the nature of the exam, i.e. only resit candidates took it.

    What does everyone else reckon an A would be?
    An a definitely won't be higher than 84 but could be anything between 75-84. The highest they've ever been were 83 in Jan 2012- but remember that was only retakers too.
    Don't freak out about it only being retakers because every Janurary f322 was only retakers aswell
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    (Original post by nicoleemmak)
    Would you not have done moles of the other thing x125 then worked out the mass from that
    Yes that is how you calculate it
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    (Original post by mercuryman)
    86/100 for an A

    100/100 for max

    Therefore, losing around 9-10 marks would score you around 137 ums/150 ums
    Which in my opinion is decent
    86?? I really hope it's not that high. There was a question worth 2 marks that I couldn't do (I can do it now, but my mind went blank in the exam unfortunately) ... and I make about 10 silly errors per paper ... Oooh it might be tight :/
 
 
 
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