In the solid phase, arsenic occurs in two forms. One form, yellow arsenic, has a density of

1.97 g/cm3 at STP. The other form, gray arsenic, has a density of 5.78 g/cm3 at STP. When arsenic is

heated rapidly in air, arsenic(III) oxide is formed.

Although arsenic is toxic, it is needed by the human body in very small amounts. The body of a

healthy human adult contains approximately 5 milligrams of arsenic. When heated, a 125.0-kilogram sample of arsenopyrite yields 67.5 kilograms of FeS.

Determine the total mass of arsenic produced in this reaction