Elemental S reacts with O2 to form SO3 according to the reaction. 2S + 3O2 → 2SO3 as depicted here. Next, consider a situation in which all of the S is consumed before all of the O2 reacts, or one in which you have excess S because all of the O2 has been used up. For each of the given situations, indicate whether S or O2 is the limiting reactant. 3.0 mol sulfur 4.0 mol oxygen, 3.0 mol sulfur 5.0 mol oxygen, 3.0 mol sulfur 3.0 mol oxygen.