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precipitation problem

Discussion in 'DAT Discussions' started by BodybldgDoc, Mar 4, 2007.

  1. BodybldgDoc

    BodybldgDoc Guest

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    If all of the chloride in a 5 gram sample of an unknown metal chloride is precipitated as AgCl with 70.9mL of 0.201 M AgNO3, what is the percentage of chloride in the sample?
    A. 50.55%
    B. 20.22%
    C. 1.43%
    D. 10.10%
    E. none of the above
     
  2. Lonely Sol

    Lonely Sol cowgoesmoo fan!
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    When I did it, I got like 7%, so i gues the answer is E, is it true.

    (i am not sure on this one, but it should be E)
     
  3. REH

    REH Junior Member
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    Maybe I'm missing something, but here's how I would go about calculating this.

    70.9 mL * 1L/1000 mL * 0.201 mol AgNO3/L * 1 mol Ag+/ 1 mol AgNO3 * 107.8 g / 1 mol Ag+ * 1/5.00 G * 100 = 30.7 %

    Answer: E, none of the above.

    If all of the chloride in a 5 gram sample of an unknown metal chloride is precipitated as AgCl with 70.9mL of 0.201 M AgNO3, what is the percentage of chloride in the sample?
    A. 50.55%
    B. 20.22%
    C. 1.43%
    D. 10.10%
    E. none of the above
     
  4. OP
    OP
    BodybldgDoc

    BodybldgDoc Guest

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    I cannot confirm what the correct answer would be but the answer to the problem is is E none of the above. From the looks of it, i think REH found the percentage of Ag instead of Cl in the sample. So,
    1-.307=.693 or 69.3% of Cl in the sample after precipitation. What do ya think?
     
  5. REH

    REH Junior Member
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    Oops! You're right. Thanks for catching that.
     
  6. OP
    OP
    BodybldgDoc

    BodybldgDoc Guest

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    no problem REH. thanks for taking the time to solve it.:)
     

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