The arsenic in a 1.22g sampleof pesticide was converted to AsO_(4)^(3-) by suitable chemical treatment .it was then titrated using Ag^(+) to form Ag_(3)AsO_(4) as a presipitate .If it took 25 mLof 0.102" M " Ag^(+) to reach to equivalence pointin this titration , what is the percentage of arsenicin the pestcide ? (As = 75)

The arsenic in a 1.22g sampleof pesticide was converted to AsO_(4)^(3-

1.	The arsenic in a 1.22g sampleof pesticide was converted to AsO_(4)^(3-) by suitable chemical treatment .it was then titrated using Ag^(+) to form Ag_(3)AsO_(4) as a presipitate .If it took 25 mLof 0.102" M " Ag^(+) to reach to equivalence pointin this titration , what is the percentage of arsenicin the pestcide ? (As = 75)
Answer» Solution :The reaction `3Ag^(+) +AsO_(4)^(3-) to Ag_(3)AsO_(4)^(3-)` is not a REDOXREACTION but a precipitation reaction . The equivalent weightsof `AsO_(4)^(3-) and Ag^(+)`= m.e of `Ag^(+)`= MMOL of `Ag^(+)` ` = 0.102 XX 25 = 2.55` Eq. of `AsO_(4)^(3-) = (2.55)/1000 = 0.00255` Mole of `AsO_(4)^(3-) = (0.00255)/3 = 0.00085` Mole of As =`0.00085 xx 75 = 0.06375 ` G Percentage of arsenic in the pesticide `= (0.06375)/(1.22) xx 100` ` = 5.22 ` %