posted by James .
Sulfur trioxide, SO3, is produced in enormous quantities each year for use in the synthesis of sulfuric acid.
S(s) + O2(g) -> SO2(g)
2SO2(g) + O2(g) -> 2SO3(g)
What volume of O2 (g) at 350 degrees Celsius and a pressure of 5.25 atm is needed to completely convert 5.00g of sulfur to sulfur trioxide?
The long way, but perhaps easier to understand, is to convert 5 g S to moles, then to mole O2 needed and moles SO2 produced in the first equation. Take the mole SO2 produced in equation 1 and use that to determine moles oxygen from equation 2. Add the two to find total moles O2. Then use PV = nRT to find volume O2. Check my thinking.