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Homework Help: Help on chemistry problem

  1. Sep 8, 2010 #1
    1. The problem statement, all variables and given/known data
    An alloy sample weighing 5.00g contains Cr. The Cr is chemically converted to a K2Cr2O7 solution. The Cr2O7^-2 ion in the solution is converted to Cr^+3 by reacting it with 4.73g of I2.

    Cr2O7^-2 + I2 --->Cr^+3 +IO3 ( need to balance redox reaction)

    2. Relevant equations

    What is the % Cr in the alloy?

    3. The attempt at a solution
     
  2. jcsd
  3. Sep 9, 2010 #2

    Borek

    User Avatar

    Staff: Mentor

    Once you balance the reaction it is a simple stoichiometry - just calculate mass of Cr in dichromate from known mass of iodine.

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