Determining salt concentration

Discussion in 'Chemistry' started by Doughman139, May 13, 2011.

  1. Doughman139 Registered Member

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    I have a chemistry project in which we need to determine the concentration of two ionic salts in an unknown aqueous solution. The salts are sodium phosphate and ammonium acetate in an unknown solution. Also provided are copper (II) sulfate, aluminum nitrate, and potassium carbonate. Any ideas on how I could do this?
     
    Last edited: May 13, 2011
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  3. Trippy ALEA IACTA EST Staff Member

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    Do you know what the salts are that you're determining the concentration of?
    Distilled water.
    A Constant voltage power supply.
    An Ammeter.
    Two graphite electrodes, and a series of reference samples might be one way of doing it.

    The water will begin to break down once you get much past 1.2 volts, however use of reference samples - if you know what you're dealing with, might be one way around this.

    (addendum)
    Alternatively, you could measure (say) a 50ml, or 100ml aliquot of the test solution, and from there take one of two paths - either you can mix it with something else that will form a precipitate, and dry the precipitate on a piece of pre-weighed filter paper (and then re weigh it). In this case you need to know the reaction that occured, to derive the mass of the ion from the original solution that was precipitated, and from knowledge of the stoichiometry of the original salt, calculate the original concentration.

    Or, you could simple evaporate the solution in a pre-weighed beaker, reweighing it once it's been dried. In this case the difference of the weights is the weight of the salt, allowing you to directly calculate its concentration (because you know the volume of the aliquot you started with. This method still requires you to know what the salt is to begin with, but requires fewer assumptions, and is the easiest to set up.
     
    Last edited: May 13, 2011
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  5. McScotty Registered Member

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    The salts are sodium phosphate and ammonium acetate in an unknown solution. Also provided are copper (II) sulfate, aluminum nitrate, and potassium carbonate.
     
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  7. phlogistician Banned Banned

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    Titration.
     
  8. Asguard Kiss my dark side Valued Senior Member

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    Mass spec

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    sorry been watching to many episodes of NCIS

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  9. valsartan Registered Senior Member

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    I think titration would be good for this. I'm not sure though of the buffer solution you can use.
     
  10. Search & Destroy Take one bite at a time Moderator

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    I have no clue about chemistry but have a few ideas to contribute to the brainstorm.

    Timing a freeze
    Ohmmeter
    Boiling away the water
    Some kind of buoy
     
  11. Believe Happy medium Valued Senior Member

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    Do your own home work.
     

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