Sulfur trioxide, SO3, is made from the oxidation of SO2, and the reaction is represented by the equation

2SO2 + O2 2SO3
A 25-g sample of SO2 gives 18 g of SO3. The PERCENT YIELD of SO3 is?

1 answer

You know from your first post about 7.0 g propane how to do stoichiometry. The number you obtained in that process is called the theoretical yield (if you had determined either CO2 or H2O). Do this one the same way. The answer you obtain will be the theoretical yield. Then

%yield = (actual yield/theoretical yield)*100 = ??
The actual yield is given in the problem as 18 g SO3.