1. Consider a spherical metal particle that is undergoing a high-temperature surface oxidation process. The product of this reaction is a nonvolatile oxide that immediately dissolves in the metal itself. The surface reaction and oxide dissolving rates are very fast compared to the oxidizer diffusion rate. Calculate an expression for the burning rate of this metal.

2. Calculate the value of the transfer number for silicon combustion in air. Show all the stoichiometric relationships in the calculation.

3. A carbon particle is large enough so that the burning rate is diffusion-controlled. In one case the carbon monoxide leaving the surface burns to carbon dioxide in the gas phase; in another, no further carbon monoxide combustion takes place. Is the burning rate of the particle different in the two cases? If so, which is larger? Explain.

4. ∗The stoichiometric reaction between Al and liquid water is being considered as a means to generate hydrogen and for underwater propulsion. Determine whether the reaction will proceed heterogeneously or in the vapor phase at 20 atm.

5. ∗Determine the adiabatic flame temperature of a particle mixture containing 2 mol of aluminum and 3 mol of copper oxide (CuO(s)). Are the reaction products gaseous, liquid, or solids?