15. Solution to Chemistry Problem

6. To determine the nickel content in steel, dissolve a sample of steel and dilute the solution to 100 ml. Add dimethylglyoxime (a complexing agent for coloring the solution) to 5.0 ml of the solution, dilute with water to 50 ml and measure photometry at l = 1.0 cm, λ = 470 nm (ε = 1.3⋅104). Calculate the mass of the sample of steel taken for analysis if the optical density value is 0.435 and the approximate mass fraction (%) of nickel in the steel is 0.5%.