33. Solution to Chemistry Problem

4. From a 0.1750 g sample of steel, after appropriate processing, 1000 ml of a colored solution of oxidized nickel dimethylglyoximine was obtained. The relative optical density of this solution, measured with respect to a comparison solution containing 30 mg Ni in 1000 ml, was 0.78. The optical densities of four standard solutions containing 9.0; 15.0; 18.0, and 24.0 mg nickel in 1000 ml were found to be 0.22; 0.48; 0.60; 0.87, respectively. Plot a calibration graph in coordinates A-C (mg/ml) and determine the percentage content of nickel in the steel.