You are using the following procedure from your lab instructions to determine th

Question

You are using the following procedure from your lab instructions to determine the copper content of a brass sample: "Approximately 35 mg of a dried brass sample (accurately measured) is put into a 250-mL Erlenmeyer flask. About 20 mL of H2O and 10 mL of concentrated HNO3 is added. This sample is digested, then quantitatively transferred to a 100-mL volumetric flask and diluted to the mark. The sample is still too concentrated, so a 1:20 dilution is accomplished by transferring 5.00 mL of this solution to another 100-mL volumetric flask and diluting to the mark." If you actually used a 31.7 mg sample of brass, and the resulting diluted solution was found to contain 13.68 mg/L of Cu, what is the %Cu in the sample?

Explanation / Answer

43.7% -- the way you prepare the sample, is to the best of my belief, immaterial.

Divide the Cu weight by the Brass sample weight to get the percentage of Cu

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.