In a hot combustion chamber, oxygen diffuses through an air film to a carbon surface where it reacts to make CO and/or CO2. The mole fraction of oxygen at z- 8 is 0.21. The reaction at the surface may be assumed to be instantaneous. No reaction occurs in the gas film. Oxygen - z=8 CO and/or CO2 z=0 if Determine the rate of oxygen diffusion per hour through one square meter of area (a) only carbon monoxide is produced at the carbon surface; (b) only carbon dioxide is produced at the carbon surface; (c) the following instantaneous reaction occurs at the carbon surface: 4C+302-2CO+2CO₂