Geology in action at home. My pyrite is precipitating iron sulfate. If I add water, I can make sulfuric acid:
2FeS2 + 7O2 + 2H2O -> 2FeSO4 + 2H2SO4
Hang on, the weather has been is ridiculously humid. Could the acid have formed formed without direct water? Gosh, my house may be polluted with acid humidity.
