A 0.5745g sample of an alloy containing principally Bismuth and Lead is dissolved in nitric acid and dilute to 250mL in a volumetric flask. A 50mL aliquot is withdrawn, the pH adjusted to 1.5 and the...

A 0.5745g sample of an alloy containing principally Bismuth and Lead is dissolved in nitric acid and dilute to 250mL in a volumetric flask. A 50mL aliquot is withdrawn, the pH adjusted to 1.5 and the  bismuth titrated with 30.26mL of 0.01024M EDTA. The pH of the solution is then increased to 5.0 and the lead titrated with 20.42mL of the same EDTA solution. Calculate the percentages of lead  and bismuth in the alloy.