on a test there was this problem:
2 SO2 + O2 <----> 2 SO3
there are 2 moles of SO2 and 1.5 moles of O2 before the reaction, after the reaction we have 1 mole of SO2, 1 mole of O2 and 1 mole of SO3, so like in this scheme:
2 SO2 + O2 <-----> 2 SO3
2 1.5 0
-1 -0.5 -1
1 1 1
Now we where asked what the limiting reagent is, so I wrote up SO2, since O2 will be in excess if we use up all the moles of SO2. The teacher however doesn't agree with me and thinks that O2 is the limiting reagent because there are less moles (1,5) of O2 available. Is this true? And why is it true? And, if I'm right: how can I convince the teacher?