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    Can someone help me, in the Jan 2012
    Q2 e) it says calculate the no. of moles of NaOH used in titration
    It says 26.4/0.050
    It's only one mark but I don't get where they got 0.050 itsn't mass/mr?
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    I clicked on the wrong chemistry exam link, and I got so confused when they were talking about Hess and bond enthalpies. xD
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    what do you guys think has been the most difficult paper so far ???
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    what colour is everyone going with for the reaction of bromine and an alkene??
    i normally put orange-colourless, but the june 2012 mark scheme wouldnt gve you orange and said it needed to be red, so i put red down in the
    jan 2013 paper, and said DO NOT ALLOW red.. kinda contradicts itself but unsure what to put now!
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    (Original post by BethanyHope)
    what colour is everyone going with for the reaction of bromine and an alkene??
    i normally put orange-colourless, but the june 2012 mark scheme wouldnt gve you orange and said it needed to be red, so i put red down in the
    jan 2013 paper, and said DO NOT ALLOW red.. kinda contradicts itself but unsure what to put now!

    Colourless to brown?
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    (Original post by Arcen348)
    Colourless to brown?
    Brown to colourless!

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    (Original post by carla6600)
    Think about this way...
    Thank you for taking the time to write this out, it was really helpful!
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    (Original post by Whostolemycookie)
    Can someone help me, in the Jan 2012
    Q2 e) it says calculate the no. of moles of NaOH used in titration
    It says 26.4/0.050
    It's only one mark but I don't get where they got 0.050 itsn't mass/mr?
    I did this:

    26.40/1000 * 0.0500 = 1.32*10^3

    Remember, Number of moles = conc. volume.
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    Can anyone upload Jan 13 paper please??
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    (Original post by JoshThomas)
    Brown to colourless!

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    Righteo brown it is then. ill try and remember as i ALWAYS put orange haha

    thank youuuu
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    (Original post by EstebanK0)
    I did this:

    26.40/1000 * 0.0500 = 1.32*10^3

    Remember, Number of moles = conc. volume.
    Ok so we divide by 1000 so that we can convert it to dm3, right?
    But where does the 0.0500 come from?

    Don't worry I get it now, 0.0500 is the conc
    so it's volume * conc

    Ok thanks alot
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    Good luck everyone!


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    Quick recap
    Aldehyde- rcoh
    ketone-rcor
    carboxylic acid-rcooh
    ether-rcoor

    Is that right?
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    Just to clarify, a reaction with POSITIVE enthalpy is ENDOthermic, whilst a reaction with NEGATIVE enthalpy is EXOthermic. Correct?
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    (Original post by Whostolemycookie)
    Quick recap
    Aldehyde- rcoh
    ketone-rcor
    carboxylic acid-rcooh
    ether-rcoor

    Is that right?
    yup as long as you remember where the double bonds are.
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    (Original post by Whostolemycookie)
    Quick recap
    Aldehyde- rcoh
    ketone-rcor
    carboxylic acid-rcooh
    ether-rcoor

    Is that right?
    I'm not sure about the ether... it's been a while since I looked at those. Isn't it basically r-o-r? Or am I thinking of something else?
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    (Original post by Kathiye)
    I'm not sure about the ether... it's been a while since I looked at those. Isn't it basically r-o-r? Or am I thinking of something else?
    It is r-o-r
    Yeah I got confused
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    (Original post by King Hotpie)
    Just to clarify, a reaction with POSITIVE enthalpy is ENDOthermic, whilst a reaction with NEGATIVE enthalpy is EXOthermic. Correct?
    Yup
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    (Original post by abzy1234)
    Yup
    Oh good now I just have to remember it for the next few hours :rolleyes:

    Does anyone know where I could find the January 2013 mark scheme?
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    (Original post by BethanyHope)
    Righteo brown it is then. ill try and remember as i ALWAYS put orange haha

    thank youuuu
    Iodine is brown too!

    Posted from TSR Mobile
 
 
 
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