How Much Chromium Is Present in the Alloy?

[grumpyasian]

Homework Statement

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)

Homework Equations

What is the % Cr in the alloy?

The Attempt at a Solution

 

[Borek]

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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