2. An incinerator handles 80kg per hour benefin (C13H16F3N3O4) and has a stack gas containing 5% oxygen by volume on a dry basis. Determine the percent excess air (both O2 and N2 gases as mol per hour and kg per hour) provided to the reactor. (Elemental weights: C=12g,N=14g,O=16g, and F=19g )