A 6.39-g sample of an ant-control preparation was decomposed by wet ashing with H2SO4 and HNO3. The arsenic in the residue was reduced to the trivalent state with hydrazine. After the excess reducing agent had been removed, the arsenic (III) was oxidized with electrolytically generated I2 in a faintly alkaline medium:
The titration was complete after a constant current of 127.6 mA had been passed for II min and 54 s. Express the results of this analysis in terms of the percentage As2O3 in the original sample.