**SPECTROPHOTOMETRIC DETERMINATION OF Mn
IN STEEL**

Obtain your unknown from the instructor. Weigh out duplicate 1.0g samples (to the nearest 0.1 mg) in 150 mL or 250 mL beakers. Add about 50 mL of 6

Solution Description |
85% H_{3}PO_{4} |
Standard Mn |
KIO_{4} |

Blank | 10 mL | 0.00 mL | 0.0 g |

Sample 1 | 10 mL | 0.00 mL | 0.8 g |

Sample 2 | 10 mL | 10.00 mL | 0.8 g |

Boil each solution gently for 5 minutes, cool, and transfer quantitatively to 100 mL volumetric flasks. Dilute to the mark, mix well, and determine the %T for each sample with the spectrophotometer adjusted to 525 nM. Convert these %T values to absorbance, and calculate the percent Mn in the original sample.

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