Answer to Question #216570 in General Chemistry for Mei

Question

A 0.3304-g sample of brass (containing lead, zinc, copper, and tin) was dissolved in nitric acid. The sparingly soluble SnO2.4H2O was removed by filtration, and the combined filtrate and washings were then diluted to 500.0 mL. A 10.00-mL aliquot was suitably buffered; titration of the lead, zinc, and copper in this aliquot required 34.78 mL of 0.002700 M EDTA. The copper in a 25.00-mL aliquot was masked with thiosulfate; the lead and zinc were then titrated with 25.62 mL of the EDTA solution. Cyanide ion was used to mask copper and zinc in a 100-mL aliquot; 10.00 mL of the EDTA solution was needed to titrated the lead ion. Determine the composition of the brass sample; evaluate the percentage of zinc by difference

Answer 1

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