# Entropy related thermodynamics question

1. Sep 25, 2006

### apsc

need a bit of help. anything would do, just need to get things started.

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FeS2 in an aqueous slurry is oxidized with 15% pure Oxygen in autoclave:
4FeS2 + 15O2 + 8H2O -> 2Fe2O3 + 8H2SO4

to sustain reatcion, a final temp of at least 220C must be achieved @ oxygen partial pressure of 800kPa

feed slurry is pure pyrite in pure water at 25C, estimate minimum pyrite pulp density (mass % solids)
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the question comes with a chart that shows molecular weight (g/mol) of each compound, the enthalpy (kJ/mol) at 298K of each compound, and the A B C to calculate heat capacity (cp) using the formula:

cp = A + (B*10^-3)T + (C*10^5)T^-2 (J/mol/K)

it also has the formula to calculate water vapour pressure.

i know how to do enthalpy calculations. but i am not sure how i can use the pressure and the temperature to calculate the mass.
any hints / suggestions will be greatly appreciated thanks.