A 25.0-mL aliquot of an aqueous quinine solution was diluted to 50.0 mL and found to have an absorbance of 0.636 at 3.48 nm when measured in a 2.50-cm cell. A second 25.0 -mL aliquot was mixed with...

A 25.0-mL aliquot of an aqueous quinine solution was diluted to 50.0 mL and found to have an absorbance of 0.636 at 3.48 nm when measured in a 2.50-cm cell. A second 25.0 -mL aliquot was mixed with 10.00mL of a solution containing 23.1 ppm of quinine; after dilution to 50.0mL, This solution had an absobance of 0.903(2.50-cm cell). Calculate the concentration of quinine in parts per million in the sample.