Potassium dichromate and potassium permanganate have overlapping absorption spectra in 1 M H2SO4. K2Cr2O7 has an absorption maximum at 440 nm, and KMNO4 has a band at 545 nm. A mixture is analyzed by measuring the absorbance at these two wavelengths with the following results: A440nm = 0.405, A545nm = 0.712 in a 1 cm cell. The absorbances of a pure solution of 1.00 x 10-3 M K2Cr2O7 in 1 M H ₂ SO ₄ are 0.374 at 440 nm, and 0.009 at 545 nm. The absorbances of a pure solution of 2.00 x 10 ^-4 M KMnO4 in 1 M H ₂ SO ₄ are 0.019 at 440 nm, and 0.475 at 545 nm. Calculate the concentrations of dichromate and permanganate in the sample solution.

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Answer According to Beers Law Absorbance K C where K b absorptivity b path length in cm and C concen... View the full answer