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    You know what really pisses me off. When on the news you constantly hear that the exams are getting too easy and too many people are coming out with As. Its not our fault you were so ****ing dumb in those days but dont mess up our life by ****ing up our exams. and as for the exams getting easier, this exam is living proof that the exams in those days are nothing with what we have to face now!
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    (Original post by SaturnineDragonfly)
    It was quite strange, usually there's some obvious thread to pick up to deduce they tell you to, but I also found that in that question there seemed to be no evident reason to choose any of the acids. I chose lactic acid as well, since the sweet has to be edible at least, so it seemed to me that the only two possibilities were lactic and ethanoic, as I doubt it's healthy to eat the acid with benzene in it (can't remember it's actual name) and pyruvic. And out of lactic acid and ethanoic acid, lactic had the lower pKa value, so was a stronger acid (and the pH had to be low, 3.55). That's the only line of reasoning I could think of. Any one else have any other reasoning or figure it out differently for some subtle reason? :confused:
    At the mid point of a buffer, pKa=pH

    So pick the acid with a pKa value closest to pH you want, in this case lactic acid fits.

    This was in the stretch and challenge box in the buffer bit of the textbook I think
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    http://www.facebook.com/pages/Studen...05631386197256
    Let our voices be heard!!!
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    Jeeeeez I revised so hard, but I still could NOT have prepared for that exam. Sooo difficult. :/
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    (Original post by msAW)
    same, my med offer is gone but i can't even think about it because theres nothing i want to do more. this paper was incredible.
    I know!! imagine taking a gap year because you miss your grades... don't want to think about it
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    (Original post by Teva)
    For finding k, did you use the initial concentration of Br2? so 0.01? in the rate equation???
    Yep, just plugged in the initial [Br2] with the inital rate to match.
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    (Original post by Acta Non Verba)
    I found the value of Delta S to be negative and thus the got somewhere in the 400s for delta G, meaning it wasn't spontaneous.
    did you divide delta S by 1000 to get it in kj ? maybe thats why people are getting negative and positive values of delta G... ?
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    (Original post by Teva)
    did you divide delta S by 1000 to get it in kj ? maybe thats why people are getting negative and positive values of delta G... ?
    I did divide it by 1000. It came out at something like -0.29
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    what did you guys get for molecular formula?
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    Oh dear. University's definitely not an option now...
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    (Original post by percy93)
    what did you guys get for molecular formula?
    i got C10H12N2
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    (Original post by SaturnineDragonfly)
    It was quite strange, usually there's some obvious thread to pick up to deduce they tell you to, but I also found that in that question there seemed to be no evident reason to choose any of the acids. I chose lactic acid as well, since the sweet has to be edible at least, so it seemed to me that the only two possibilities were lactic and ethanoic, as I doubt it's healthy to eat the acid with benzene in it (can't remember it's actual name) and pyruvic. And out of lactic acid and ethanoic acid, lactic had the lower pKa value, so was a stronger acid (and the pH had to be low, 3.55). That's the only line of reasoning I could think of. Any one else have any other reasoning or figure it out differently for some subtle reason? :confused:

    Although, thinking about it, pyruvic is possibly edible? I really don't know.
    I chose LACTIC ACID TOO MATE
    YEAHHHHHHH
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    so difficult. i went over everything and still couldn't have been prepared enough for that exam
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    (Original post by student777)
    At the mid point of a buffer, pKa=pH

    So pick the acid with a pKa value closest to pH you want, in this case lactic acid fits.

    This was in the stretch and challenge box in the buffer bit of the textbook I think
    I was thinking about (trying to remember ) what was in that box, since it had some information about ratios. I'm glad I chose lactic acid, although it was for the wrong reason, but it will only be 1 mark for the reason I expect. :confused: How did you respond to the validity part of that question?
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    (Original post by student777)
    At the mid point of a buffer, pKa=pH

    So pick the acid with a pKa value closest to pH you want, in this case lactic acid fits.

    This was in the stretch and challenge box in the buffer bit of the textbook I think
    I'm looking at the text book and I can't find how pKa relates to pH anywhere nor have I learnt it, what page is it on?
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    (Original post by percy93)
    what did you guys get for molecular formula?
    Was it the question about nickel with 6 water molecules. I got Ni(NH3)6 for the molecule with 160.7 mass. can't remember what i got for the rest.
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    (Original post by student21)
    i went through the syllabus 4 ****ing times and still ****ed up! 4 times, 4 ****in times. What the hell were we sitting today a phd paper? I bet even those are easier lol.
    who found that easy??? Im sorry but how??? What kind of revision did you ****ing do??? Because i seem to be missing somehting here...every ****ing person in my college found it ok...ok.??!?! Ok?!?!? I cudnt even attempt the ****ing questoins forget even trying to find it ok?!?!?
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    Were the isomers optical? I completely guessed that one, and for the molecular formula : C10H10N2?
    And my ligand thingys were:
    Ni(H20)2CL4 but I accidentally put 2+ oops?

    Ni(OH)2

    Ni(NH3)6

    Equation:
    Ni(H20)6 + 6NH3 ----> Ni(NH3)6 + 6H20
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    (Original post by BackDoorEntry)
    i got 4x10^-3 s^-1 using a tangent at t=0
    got that as well

    (Original post by Acta Non Verba)
    I found the value of Delta S to be negative and thus the got somewhere in the 400s for delta G, meaning it wasn't spontaneous.
    ave
    yeah same!
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    k=0.00342?? anyone else get something like this
 
 
 
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