P23-27: Molar absorptivity data for the cobalt andnickel complexes with 2,3-
quinoxalinedithiol are εCo = 36,400 and εNi = 5520 at 510 nm andεCo = 1240 and εNi = 17,500 at 656 nm. A 0.425-g sample wasdissolved and diluted to 50.0 mL. A 25.0-mL aliquot was treated toeliminate interferences; after addition of 2,3quinoxalinedithiol,the volume was adjusted to 50.0 mL. This solution had an absorbanceof 0.446 at 510 nm and 0.326 at 656 nm in a 1.00-cm cell. Calculatethe parts per million of cobalt and nickel in the sample.
