# Question: find the weight percent of iron 5585 gmol in a...

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Find the weight percent of iron (55.85 g/mol) in a rock. Suppose that a 0.1773 g rock is crushed and dissolved in nitric acid. The solution is diluted to 100.00 mL. Then 15.00 mL of this solution is mixed with 10 mL 0.200 M chromophore. The resulting Fe complex has an absorption of 0.431 at 508 nm. A second solution is prepared exactly the same as above but spiked with 1 mL of 750 ppm Fe solution, which then gives an absorption of 0.808.