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!! LC Chemistry '16 HL - Before and after ...

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135

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    #62
    DownOneTourist
    Registered Users Posts: 182 ✭✭DownOneTourist


    medhopeful16 wrote: »
    I got 8.9 I think but close enough!

    Range of 8-11 perhaps


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    #63
    cuprugby333
    Registered Users Posts: 39 ✭cuprugby333


    Seaaan wrote: »
    Q1 was meh. Q4 lovely, Q4 lovely, 5 lovely, 6 lovely, 11 lovely and 10 wasn't bad either.

    Equilibrium constant answer, anyone? I got 78.4

    Kc? I got 196000 and others in my class did as well


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    #64
    cuprugby333
    Registered Users Posts: 39 ✭cuprugby333


    I think I messed up my titration calculation by using naoh instead of ethanoic acids mr. Also wasn't sure on the diagram for bemzoic acid melting. Q5 was phrased poorly I thought other than that it was all fine I think


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    #65
    DownOneTourist
    Registered Users Posts: 182 ✭✭DownOneTourist


    cuprugby333 wrote: »
    Kc? I got 196000 and others in my class did as well

    I got that too


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    #66
    BrownTrout
    Closed Accounts Posts: 216 ✭✭BrownTrout


    cuprugby333 wrote:
    Kc? I got 196000 and others in my class did as well


    Yeah that's the correct one


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    #67
    Seaaan
    Registered Users Posts: 626 ✭✭✭Seaaan


    How did ye get that high a number.. It was in a 50L vessel so I have no idea how to have gotten such a high number


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    #68
    Seaaan
    Registered Users Posts: 626 ✭✭✭Seaaan


    cuprugby333 wrote: »
    I think I messed up my titration calculation by using naoh instead of ethanoic acids mr. Also wasn't sure on the diagram for bemzoic acid melting. Q5 was phrased poorly I thought other than that it was all fine I think

    I agree with Q5 part, the one regarding the origin of series of lines especially. I explained Bohr model for thay


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    #69
    juniorcert
    Registered Users Posts: 123 ✭✭juniorcert


    So relieved with how that went, went into the exam feeling like I knew nothing, thank God that was a good paper. Unfortunately I messed up most of my calculations, should have revised them more but everything else went well so might actually get my B2 :)


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    #70
    cuprugby333
    Registered Users Posts: 39 ✭cuprugby333


    Seaaan wrote: »
    How did ye get that high a number.. It was in a 50L vessel so I have no idea how to have gotten such a high number

    You divide by 50. So division by a number less than 1 Is like multiplication


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    #71
    alaandocs
    Registered Users Posts: 33 ✭alaandocs


    Divide the amounts that were left by 50, then in the kc equation square the so3 amount and divide by the so2 squared by O2 and you get 196000


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    #72
    BrownTrout
    Closed Accounts Posts: 216 ✭✭BrownTrout


    Seaaan wrote:
    How did ye get that high a number.. It was in a 50L vessel so I have no idea how to have gotten such a high number

    1.5 moles of SO2 in 50 litre vessel is 0.03 moles in 1 litre etc.


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    #73
    medhopeful16
    Registered Users Posts: 59 ✭✭medhopeful16


    cuprugby333 wrote: »
    You divide by 50. So division by a number less than 1 Is like multiplication

    I did that first but thought that a really high number was wrong so instead I went back and multiplied. Oh well


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    #74
    luftmensch
    Closed Accounts Posts: 140 ✭✭luftmensch


    cuprugby333 wrote: »
    Kc? I got 196000 and others in my class did as well

    I got 196 but forgot that it was a 50 litre vessel.


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    #75
    daraghwal
    Registered Users Posts: 946 ✭✭✭daraghwal


    lc16_ wrote: »
    Q1) Iron Tablets exp
    Q2) Ethene/Ethyne
    Q3) Rates of reaction exp
    Q4) Short qs heavily on defintions
    Q5) Trends in periodic table & bonding
    Q6) Thermochemistry equations & Fuels, hydrocarbon definitions
    Q7) Long water q
    ...Q11) A- Gas laws & calculations
    B- Equilibrium defs & calc
    That would be an absolute beauty of a paper :D

    There was so little of that on it and still it was a beauty! :D


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    #76
    DownOneTourist
    Registered Users Posts: 182 ✭✭DownOneTourist


    daraghwal wrote: »
    There was so little of that on it and still it was a beauty! :D

    It was all there bar 2 or 3 things


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    #77
    Seaaan
    Registered Users Posts: 626 ✭✭✭Seaaan


    I divided after kc, I'm an idiot. Should pick up most of the marks for that at least :o


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    #78
    DownOneTourist
    Registered Users Posts: 182 ✭✭DownOneTourist


    Seaaan wrote: »
    I divided after kc, I'm an idiot. Should pick up most of the marks for that at least :o

    Absolutely. That is only 1 of the 4 steps. Initial, change, moles at eq, then the volume part


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    #79
    luftmensch
    Closed Accounts Posts: 140 ✭✭luftmensch


    What was the % w/v on Q1?


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    #80
    onlinenerd
    Registered Users Posts: 195 ✭✭onlinenerd


    luftmensch wrote: »
    What was the % w/v on Q1?

    I got 1.3%


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    #81
    BrownTrout
    Closed Accounts Posts: 216 ✭✭BrownTrout


    luftmensch wrote:
    What was the % w/v on Q1?


    4.8?


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    #82
    pvakelly
    Registered Users Posts: 136 ✭✭pvakelly


    BrownTrout wrote: »
    4.8?

    Got 4.8% too!


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    #83
    Bangdiggy
    Registered Users Posts: 36 ✭Bangdiggy


    cuprugby333 wrote: »
    Kc? I got 196000 and others in my class did as well

    Yeah I got 196000 too yes! Beaming


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    #84
    louisoc
    Registered Users Posts: 32 ✭louisoc


    I got a Kc of 196000 too. What kind of figures did people get for 11.(a)? I got sulfur in excess, with a volume of like 7.84ltrs and a mass of 9.4g


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    #85
    DownOneTourist
    Registered Users Posts: 182 ✭✭DownOneTourist


    I think I got 0.064g/100cm3


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    #86
    LordHypnos
    Registered Users Posts: 77 ✭✭LordHypnos


    what were the two titrations in the last part of Q1?


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    #87
    bookworm20
    Registered Users Posts: 38 ✭bookworm20


    cuprugby333 wrote: »
    Kc? I got 196000 and others in my class did as well

    I got that too


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    #88
    louisoc
    Registered Users Posts: 32 ✭louisoc


    LordHypnos wrote: »
    what were the two titrations in the last part of Q1?

    I said sodium carbonate against hcl, then standardised hcl against sodium hydroxide


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    #89
    Seaaan
    Registered Users Posts: 626 ✭✭✭Seaaan


    louisoc wrote: »
    I got a Kc of 196000 too. What kind of figures did people get for 11.(a)? I got sulfur in excess, with a volume of like 7.84ltrs and a mass of 9.4g

    I got that too


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    #90
    LordHypnos
    Registered Users Posts: 77 ✭✭LordHypnos


    louisoc wrote: »
    I said sodium carbonate against hcl, then standardised hcl against sodium hydroxide

    thought so, Q2 was a kick in the sack. Didn't bother revising benzoic acid but other than that, Q5 and Q11, I think I did well


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    #91
    BrownTrout
    Closed Accounts Posts: 216 ✭✭BrownTrout


    LordHypnos wrote:
    thought so, Q2 was a kick in the sack. Didn't bother revising benzoic acid but other than that, Q5 and Q11, I think I did well

    I had a gut feeling that Benzoic was going to show face again, lucky I revised it!


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