Ore Pyrites (FeS2) is converted to sulfur dioxide (SO2) gas according to the reaction

4FeS2 (s)+11 O2 (g )===> 2 Fe2O3 (s)+ 8 SO2 (g)

The air, which is 35% excess (based on the above reaction) for combustion, enters at 27°C, the ore at 18°C, and the products leave at 900K. Because of equipment degradation, unburned FeS2 exits from the process. In one hour 8000 kg of pyrites are fed to the process, and 2000 kg of Fe2O3 are produced.

(A) What is the heat added or removed from the process? [10]

(B) Explain how you would calculate the adiabatic heat of the reaction if the inlet temperature of both reactants (assuming both of the reactants enter at same temperature) is not specified. List each step only (you are not supposed to do the calculations here). [6]

Data:

For FeS2:

Cp = 44.77 + 5.590 x 10–2T where T is in Kelvin and Cp is in J/(g mol)(K).

For Fe2O3:

Cp = 103.4 + 6.71x 10-2T with the same units