Question

Copper is added to steel in amounts greater than 0.2% but less than 1.5% as it strengthens, hardens and reduces corrosion of the product. The amount of copper in a steel product is determined by digesting the steel product with strong acid, converting all copper species to the Cu+1 ion, complexing the Cu+1 ion to form a light absorbing species by reaction with neocuproine, and extracting the coloured complex with isoamyl alcohol for analysis by UV/VIS spectrophotometry at the 454 nm absorbance wavelength. A 0.2108 g sample of a standard steel sample containing 0.42% of copper was analysed by the above process and a final 10.00 mL volume of the isoamyl extract was obtained. The copper complex of this solution gave an absorbance of 0.481 using a 1.00 cm cuvette. A 0.2892 g sample of a steel product that was being manufactured was analysed as above using the same procedure and equipment and a final 10.00 mL volume of the isoamyl extract was obtained. The copper complex of this solution gave an absorbance of 0.632 using a 1.00 cm cuvette. A blank solution carried through the same procedure gave an absorbance of 0.038. What is the percentage of copper in the manufactured steel product? Is the copper in this steel product within the specified range given above. Note. You have to take into consideration the absorbance of the blank solution to solve the problem.

Answer 1