If 96 g SO2 is added to 2 moles of oxygen at STP, calculate the volume of SO3 that is formed
2SO2 + O2 ==> 2SO3
This is a limiting reagent (LR) problem. You know that when amounts are given for more than one reactant.
mols SO2 you have = grams/molar mass = 96/64 = 1.5
1.5 mols SO2 can form 1.5 mols SO3.
2 mols O2 can form 4 mols SO3.
In LR problems the SMALL number always wins; i.e. in this case you have enough oxygen to react completely with 1.5 moles SO2 but not enough SO2 to react completely with 2 mols Oxygen. Therefore, SO2 is the LR and you will form 1.5 moles SO3
1 mols of any gas will form 22.4 L @ STP so 1.5 mols SO3 will have a volume of ............