In the reaction 2so2+o2--->2so3. When 1 mole of so2 and 1 mole of o2 are made to react to completion. 1) all the oxygen ll be consumed. 2)1.0mole of so3 ll be produced. 3)0.5mole of so2 is remained. 4) all of these.
2nd option is correct
2mole so2 reacts with 1 mole o2
therefore, 1 mole so2 will react with 0.5 mole o2
this means,o2 is excess reagent and so2 is limiting
2 mole so2 form 2 mole so3
therefore 1 mole so2 will form 1 mole so3..