Calamine, which is used for relief of skin irritations, is a mixture of zinc and iron...

 

Transcribed Image Text:

Calamine, which is used for relief of skin irritations, is a mixture of zinc and iron oxides. A 1.022-g sample of dried calamine was dissolved in acid and diluted to 250.0 mL. Potassium fluoride was added to a 10.00-mL aliquot of the diluted solution to mask the iron; after suitable adjustment of the pH, Zn2* consumed 38.71 mL of 0.01294 M EDTA. A second 50.00-mL aliquot was suitably buffered and titrated with 2.40 mL of 0.002727 M ZnY2- solution: Fe3+ + ZnY2- FeY + Zn2+ Calculate the percentages of Zno and Fe,03 in the sample. Calamine, which is used for relief of skin irritations, is a mixture of zinc and iron oxides. A 1.022-g sample of dried calamine was dissolved in acid and diluted to 250.0 mL. Potassium fluoride was added to a 10.00-mL aliquot of the diluted solution to mask the iron; after suitable adjustment of the pH, Zn2* consumed 38.71 mL of 0.01294 M EDTA. A second 50.00-mL aliquot was suitably buffered and titrated with 2.40 mL of 0.002727 M ZnY2- solution: Fe3+ + ZnY2- FeY + Zn2+ Calculate the percentages of Zno and Fe,03 in the sample.

Answer rating: 100% (QA)

Moles of EDTA consumed by Zn2aq MxVL 001294 molL x 003871 ... View the full answer