The correct option is B Some O2 remains unreacted
When 100 grams of O2 are allowed to react completely with 1.0 mole of C2H4 according to the equation C2H4(g)+3O2(g)⟶2CO2(g)+2H2O(l), some O2 remains unreacted.
The molecular weight of O2 is 32 g/mol.
100 grams of O2 corresponds to 10032=3.125 moles.
According to the given equation ,
1.0 mole of C2H4 reacts with 3 moles of O2. Hence C2H4 is limiting reagent and O2 is excess reagent. Hence, some O2 remains unreacted.