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Homework Help: Dilution question

  1. May 12, 2010 #1
    Hey,

    I have a solution of 18 wt % (about 1g/ml) I want to make it into a solution of 2 wt % by diluting it with water. Using C1 V1 = C2 V2 could someone show me how to do it. I have tried but seem to be getting muddled somewhere.

    Thanks!
     
  2. jcsd
  3. May 12, 2010 #2

    Borek

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    Staff: Mentor

    You need to know (or assume) initial (or final) volume.

    Show what you did, we will start from there.

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  4. May 12, 2010 #3
    Final desired volume 10ml

    18% of 1g = 180mg


    C1 V1 = C2 V2
    (180mg/ml)(X) = (2mg/ml) (10ml)
    X = 2 (10) / 189
    X = 0.11 ml <--- which seems too low
     
  5. May 12, 2010 #4

    Borek

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    Staff: Mentor

    Why 2 mg/mL?

    --
     
  6. May 12, 2010 #5
    I mean 2 wt percentage of the final solution
     
  7. May 12, 2010 #6

    Borek

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    Staff: Mentor

    Perhaps that's what you mean, but does 2 mg/mL equal 2%?

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    methods
     
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