posted by Cameron .
A sample of iron(II) sulfate was heated in an evacuated container to 920 K, where the following reactions occurred.
Reaction (a): 2 FeSO4(s)--> Fe2O3(s) + SO3(g) + SO2(g)
Reaction (b): SO3(g)--> SO2(g) + 1/2 O2(g)
After equilibrium was reached, the total pressure was 0.836 atm and the partial pressure of oxygen was 0.0275 atm. Calculate Kp for each of these reactions
I'm having the most trouble with finding the partial pressures.