When an airbag expands in a vehicle, sodium azide reacts with potassium nitrate and silicon dioxide, releasing nitrogen gas and sodium potassium silicate (fine glass powder) 6 NaN3+ 2 KNO3 + 4 SiO210 N2+ 2 NaKSiO3+ 2 Na2SiO3 + 02 To conduct a similar reaction, 2.0 mol of NaN3, 1.0 mol of KNO3 and 1.8 mol of SiO2 are added. Which one is the limiting reactant? a) N2 b) O2 c) KNO3 d) SiO2