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OCR Salters Chemistry B F332 Advance Notice Jan 2011 Understanding Our Changing Atmos Watch

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    (Original post by MyJunkIsYou)
    what did people get for the bond enthalpy question? thought it was a bit cheeky they changed it round from way they've done it in all the past papers. i think i got something like 348kJ :/

    and the mole ratio one? how were you supposed to work it out? had no idea what to do, moved on and just bunged down 1:0.5 in a last minute rush
    Haha same, had like 10 seconds to go so just put that
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    (Original post by MyJunkIsYou)
    oh yeah well i got something to the 10^-19 for the first part, calculating the energy for a single bond.

    And then it wanted the bond enthalpy in kj if i remember. that's what i got 348kj for. but then again i wasn't sure whether to divide or times by the avogadro constant so knowing me i probably did the wrong thing!
    No you did it right, the answer was 348kj
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    (Original post by Darthdevidem)
    How many marks do you think we'll need for 90 UMS or 100UMS?

    For 90 I reckon 82/100 raw marks

    For 100 I reckon 90/100 raw marks

    Anyone else agree?
    Isn't the UMS out of 150 for this paper? Or have i just made this up? :confused:

    You may know this but i am guessing not as 100 ums for 90/100 marks would mean full marks (100) for 150 and that would be plain mean
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    (Original post by Will170393)
    No you did it right, the answer was 348kj
    oo well hopefully that's at least 4 marks out of the hundred i got then ha
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    (Original post by Darthdevidem)
    How many marks do you think we'll need for 90 UMS or 100UMS?

    For 90 I reckon 82/100 raw marks

    For 100 I reckon 90/100 raw marks

    Anyone else agree?
    72 raw marks for 120 UMS
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    (Original post by Will170393)
    Haha same, had like 10 seconds to go so just put that
    Wow that was a popular guess! I did it aswell.

    Though I did do a random method and got 0.4 but u still put 0.5
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    [QUOTE=catz64;29481975]Isn't the UMS out of 150 for this paper? Or have i just made this up? :confused:QUOTE]

    Pretty sure it is 150 UMS
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    (Original post by jpurkis1)
    The answer of X * 10^-19 needed to be multiplied by avogadro's constant (6.02 * 10 ^23) to work out the bond enthalpy. They might accept answers in a range of between 320 - 370, from what I've seen and heard from people.
    Ahhh balls. I divided Avagadros constant. i converted my answer to KJ tho, maybe i got 1 mark out of the 2.

    What did you get for the equilbrium quesition? and the alkene question (what are alkenes for)
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    (Original post by Darthdevidem)
    How many marks do you think we'll need for 90 UMS or 100UMS?

    For 90 I reckon 82/100 raw marks

    For 100 I reckon 90/100 raw marks

    Anyone else agree?
    It is a 150 UMS paper, so I think 90/100 raw marks would be a lot more :P as you aren't going to get 50 UMS marks from the last 10 raw marks...
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    What was the reagent and condition for the propane to 2-chloropropane reaction?

    I has no idea so I just guessed heat and HCL
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    What was the reagent and condition for the propane to 2-chloropropane reaction?

    I has no idea so I just guessed heat and HCL
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    (Original post by tom108)
    Ahhh balls. I divided Avagadros constant. i converted my answer to KJ tho, maybe i got 1 mark out of the 2.

    What did you get for the equilbrium quesition? and the alkene question (what are alkenes for)
    You should get 1 mark for the method.

    Which equilibrium question; there were two?

    And for source of alkene I put crude oil.

    --

    (Original post by gozatron)
    What was the reagent and condition for the propane to 2-chloropropane reaction?

    I has no idea so I just guessed heat and HCL
    I put conc. hydrochloric acid at stp.

    Wikipedia ( http://en.wikipedia.org/wiki/Isopropyl_chloride ) says reflux with conc. HCl.
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    (Original post by gozatron)
    Wow that was a popular guess! I did it aswell.

    Though I did do a random method and got 0.4 but u still put 0.5
    I realised I had left it blank in the last few minutes and did some frantic fiddling around on my calculater and also got 0.4 :dontknow:
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    (Original post by jpurkis1)
    You should get 1 mark for the method.

    Which equilibrium question; there were two?

    And for source of alkene I put crude oil.

    --



    I put conc. hydrochloric acid at stp.

    Wikipedia ( http://en.wikipedia.org/wiki/Isopropyl_chloride ) says reflux with conc. HCl.
    Both of them... I went on about ho the system would counteract the change in both of them, and said they yeild would increase for temperature, and decrease for pressure. think i was wrong.

    Would making plastics be right for the ethene quesiton?
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    (Original post by tom108)
    Both of them... I went on about ho the system would counteract the change in both of them, and said they yeild would increase for temperature, and decrease for pressure. think i was wrong.

    Would making plastics be right for the ethene quesiton?
    i said to make polypropene e.g. fibres?? -.-
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    (Original post by tom108)
    Both of them... I went on about ho the system would counteract the change in both of them, and said they yeild would increase for temperature, and decrease for pressure. think i was wrong.

    Would making plastics be right for the ethene quesiton?
    Increase pressure: Favour side with least gas molecules, so shift to left, increasing yield.
    Increase temperature: Favour endothermic side as system moves to remove extra heat. Reactants-forming reaction was endothermic, and so yield decrease.

    I thought the alkene question at the front of the paper was asking for a source, not a use of, the alkene :confused: ...
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    Were the equilibrium questions out of 2 or 3?
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    2 marks each.

    Methinks.
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    (Original post by gozatron)
    Wow that was a popular guess! I did it aswell.

    Though I did do a random method and got 0.4 but u still put 0.5
    I think the ratio of Na:K was 1:0.85

    Potassium (K) is 39.1
    Na is 23, but there was twice as many, so 2Na = 46

    For the Na: as one, 46/46 = 1
    For the Potassium, 39.1/46 = 0.85
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    (Original post by goodezy12)
    I think the ratio of Na:K was 1:0.85

    Potassium (K) is 39.1
    Na is 23, but there was twice as many, so 2Na = 46

    For the Na: as one, 46/46 = 1
    For the Potassium, 39.1/46 = 0.85
    It was a 1 or 2 mark question. If they wanted you to use the molecular mass they would have given it below the question.
 
 
 
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