Converting delta G units

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    if delta G is 29500 J mol-1
    would it be 29.5 kJmol-1 ?

    If it was -657824.4 Jmol-1
    would it be -658kJmol-1


    I'm asking this because my revision guide says the first one is 295 and the second one is -65.8

    help please
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    29 500 = 29.5 thousand (to 3sf)

    657 824.4 = 658 thousand (to 3sf)
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    (Original post by kiiten)
    if delta G is 29500 J mol-1
    would it be 29.5 kJmol-1 ?

    If it was -657824.4 Jmol-1
    would it be -658kJmol-1


    I'm asking this because my revision guide says the first one is 295 and the second one is -65.8

    help please
    Revision guide is bogus
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    (Original post by AlexFam)
    Revision guide is bogus

    But its a CGP one
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    (Original post by kiiten)
    But its a CGP one
    CGP = Crap Guide, People ...
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    (Original post by kiiten)
    But its a CGP one
    It's also wrong
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    Nah, CGP ones are kinda good but you have to take the information with a bit of salt; try not to rely on it too much.
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    (Original post by kiiten)
    But its a CGP one
    Are you sure you read the question correctly? 0.7MJmol-1 is an awfully large energy change.
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    (Original post by alow)
    Are you sure you read the question correctly? 0.7MJmol-1 is an awfully large energy change.
    C=O bond energy in CO2 is about 802 kJ mol-1 :dontknow:
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    (Original post by alow)
    Are you sure you read the question correctly? 0.7MJmol-1 is an awfully large energy change.
    Yeah ques 1.a)i) and 2.a)

    - sorry its a bit dark :3
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    (Original post by alow)
    Are you sure you read the question correctly? 0.7MJmol-1 is an awfully large energy change.
    I also have another ques - about born haber cycle for KBr.

    So if you put KBr (s) at the bottom then on the left hand side (starting from the bottom going up) is it

    K (s) + 1/2 Br2 (g)

    then

    K (g) + 1/2 Br2 (g)

    (atomisation of metal)
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    (Original post by kiiten)
    I also have another ques - about born haber cycle for KBr.

    So if you put KBr (s) at the bottom then on the left hand side (starting from the bottom going up) is it

    K (s) + 1/2 Br2 (g)

    then

    K (g) + 1/2 Br2 (g)

    (atomisation of metal)
    Bump

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    Any chance you could draw what you're describing in terms of a Born Haber cycle and post a picture? It's quite hard to work out exactly what you mean by your description and a picture speaks 1000 words
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    (Original post by MexicanKeith)
    Any chance you could draw what you're describing in terms of a Born Haber cycle and post a picture? It's quite hard to work out exactly what you mean by your description and a picture speaks 1000 words
    Oh yeah of course - sorry its a bit messy

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    (Original post by kiiten)
    Oh yeah of course - sorry its a bit messy

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    yes, although with BH it does not matter if you deal with the metal or the non-metal first.

    Check out the Born Haber cycles on this page
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    (Original post by charco)
    yes, although with BH it does not matter if you deal with the metal or the non-metal first.

    Check out the Born Haber cycles on this page
    So was I right to cross out the 1/2 and 2 on Br (see diagram)?
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    (Original post by kiiten)
    So was I right to cross out the 1/2 and 2 on Br (see diagram)?
    No, you were wrong.

    Your first step is atomisation of potassium

    Your second step is atomisation of bromine.
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    (Original post by charco)
    No, you were wrong.

    Your first step is atomisation of potassium

    Your second step is atomisation of bromine.
    Ah ok, thanks
 
 
 
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