Potassium dichromate and potassium permanganate have over lapping absorption spectra in 1mol·L -1 H 2 SO 4 . K 2 Cr 2 O 7 has an absorption maximum at 440nm,and KMnO 4 has a band at 545nm. A mixture is analyzed by measuring the absorbance at these two wavelengths with the following result:A 440 =0.405,A 545 =0.712 in a 1.00cm cell(approximate;exact length not known). The absorbances of pure solution of K 2 Cr 2 O 7 (1.00×10 -3 mol·L -1 )and KMnO 4 (2.00×10 -4 mol·L -1 )in 1mol·L -1 H 2 SO 4 ,using the same cell gave the following resuits; A Cr,440 =0.374,A Cr,545 =0.009,A Mn,440 =0.019,A Mn,545 =0.475. Calculate the concentrations of dichromate and permanganate in the sample solution.