Chapter 4, Problem 4.82PAE

4.88 A quality control technician needs to determine the percentage of arsenic (As) in a particular pesticide. The pesticide is dissolved and all of the arsenic present is converted to arsenate ions (AsO₄^3-). Then the amount of AsO₄³- is determined by titrating with a solution containing silver ions (Ag⁺). The silver reacts with the arsenate according to the following net ionic equation:

   ${\text{3 Ag}}^{+}\left(\text{aq}\right)+{\text{ AsO}}_{\text{4}}{}^{\text{3}-}\left(\text{aq}\right)\to {\text{ Ag}}_{\text{3}}{\text{AsO}}_{\text{4}}\left(\text{s}\right)$

When a 1.22-g sample of pesticide was analyzed this way, it required 25.0 mL of 0.102 M Ag+ solution to precipitate all of the AsO₄^3-. What was the mass percentage of arsenic in the pesticide?