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Homework Help: Weight of precipitate? -

  1. Sep 19, 2008 #1


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    1. The problem statement, all variables and given/known data
    0.790 g of silver nitrate and 0.473 g of potassium bromate are added to 379 mL water. Solid silver bromate is formed, dried, and weighed. What is the mas in g of the precipitated silver bromate?

    2. Relevant equations
    AgNO3 + KBrO3 --> AgBrO3 + KNO3

    AgNO3 = 169.87 g
    KBrO3 = 197.00 g
    AgBrO3 = 235.776 g
    KNO3 = 101.10 g

    3. The attempt at a solution

    169.87g AgNO3 => 235.78g AgBrO3
    0.790g AgNO3 => (235.78g AgBrO3/ 169.87g AgNO3) * 0.790g AgNO3= 1.0965 g AgBrO3

    167.005 KBrO3 => 235.78g AgBrO3
    0.473g KBrO3=> (235.78g AgBrO3/167.005 KBrO3)*0.473g KBrO3 = 0.668 g AgBrO3

    Limiting Reactant is KBrO3, thus the answer would be 0.668 g AgBrO3, also how many significant figures should we use?
  2. jcsd
  3. Sep 19, 2008 #2


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    Science Advisor
    Homework Helper

    Method seems fine , the significant figures should be 3.
  4. Sep 19, 2008 #3


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    Staff: Mentor

    Kso = 10-4.3 or something close to that number. That means that after 0.214g of AgBrO3 precipitates solution becomes saturated.

    Unless what you wrote on chemicalforums is true, and you have to assume AgBrO3 is completely insoluble...
  5. Sep 20, 2008 #4
    That method worked for me as well. Answer would be 6.68e-1
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