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Homework Help: 9 Solution Problem Lab

  1. Oct 19, 2007 #1
    Ok, so I'm sure many of you have heard of this lab.
    The instructor hands out 9 unknown solutions, and it's your goal to label each.
    The names have been given to us a day before and we are allowed to research the elements.
    The list of elements include:
    BaCl2; Cu(NO3)2; CuSO4; HCl; Hg2(NO3)2; KNO3; K2CrO4; AgNO3; and Na2S
    So far I've gathered that:
    Barium Sulfate will be a thick white precip.
    Barium Chromate is yello
    Copper (II) Nitrate is blue crystals, when hydrated
    Copper (II) Sulfate is a blue power, when hydrated
    Potassium Chromate is bright yellow, red cloud with Ag, Brown with Cu, and a yellow precip. will form with Barium.
    Also that AgNO3 is colorless
    I need help finding ways to mix these to figure out their identities, with as little mixes possible, and only the aqueous solutions are available to us, with watch glasses :cry:
  2. jcsd
  3. Oct 19, 2007 #2


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    Separate out the colored from the non-colored. Which of the above have color? Tenatively label these.

    Start adding drops of the colorless ones together. Which one(s) will form a precipitate? What color will it (they) likely be? A smell? Once you have made some tenative identifications of the colorless solutions you are ready to start adding the colored solutions to the colorless ones. Which will form precipitates? What color will they be? Do any of them smell?
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