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    hi all, hope you're all having a nice easter holiday! im not ha, doing chemistry coursework.

    anyway! I'm quite stuck on how to work out the concentration of a solution that I've diluted.
    the substance i'm using is potassium peroxodisulphate of concentration 0.040moldm^-3.

    the concentration of 25cm^3 potassium peroxodisulfate with no water would be 0.040moldm^-3.
    but what if I diluted it, say 23cm^3 of p.p with 2cm^3 of water, how would I work out the concentration?

    thanks for your help!
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    Concentration = moles * volume

    Just put in the new volume


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    (Original post by alexandraa)
    Concentration = moles * volume

    Just put in the new volume


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    hey thanks for the reply!
    moles? moles of p.p??
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    (Original post by calmpeach)
    hey thanks for the reply!
    moles? moles of p.p??
    Yes you just use the original moles of the p.p.




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    (Original post by alexandraa)
    Yes you just use the original moles of the p.p.




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    alright, so the original moles of p.p in 25cm^3 is: 0.040 * 25/1000 = 0.001

    then multiply that by the new volume, 23, 0.001x23 = 0.023moldm^-3

    is that right??
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    (Original post by calmpeach)
    hi all, hope you're all having a nice easter holiday! im not ha, doing chemistry coursework.

    anyway! I'm quite stuck on how to work out the concentration of a solution that I've diluted.
    the substance i'm using is potassium peroxodisulphate of concentration 0.040moldm^-3.

    the concentration of 25cm^3 potassium peroxodisulfate with no water would be 0.040moldm^-3.
    but what if I diluted it, say 23cm^3 of p.p with 2cm^3 of water, how would I work out the concentration?

    thanks for your help!
    Conc = moles * volume

    0.04 = 25/1000 * m

    Moles in 25 cm 3 is 1.6

    1.6/25 is 0.064 moles in every cm3

    So there would be 1.472 moles in 23 cm3

    Conc = moles * volume
    = 1.472 * 23/1000
    0.0339 Moldm-3


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    Oo I see! Thanks a lot!!


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