A 6.27-g sample of an ant-control preparation was decomposed by wet ashing with H 2 SO 4 and HNO 3 . The arsenic in the residue was reduced to the trivalent state with hydrazine. After the excess...

A 6.27-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 150.2 mA had been passed for 10 min and 34 s. Express the results of this analysis in terms of the percentage As₂O₃
in the original sample.