FeS2 is a reducing agent, H2SO4 is an oxidizing agent, FeS2 is a reducing agent.
Reactants:
H2SO4 – Sulfuric acid
Other names: Oil of vitriol, Sulfuric acid, concentrated (> 51% and , H2SO4
Appearance: Clear, colorless liquid ; Odourless colourless oily hygroscopic liquid ; Colorless to dark-brown, oily, odorless liquid. [Note: Pure compound is a solid below 51°F. Often used in an aqueous solution.]
FeS2
Names: Ferrous disulfide, Fool's gold, Iron disulfide
Products:
H2O – Water, oxidane
Other names: Water (H2O), Hydrogen hydroxide (HH or HOH), Hydrogen oxide
Appearance: White crystalline solid, almost colorless liquid with a hint of blue, colorless gas
SO2 – Sulfur dioxide
Other names: Sulfurous anhydride, Sulphur dioxide, Sulfurous acid anhydride
Appearance: Colorless gas ; Colourless gas or compressed liquefied gas with pungent odour ; Colorless gas with a characteristic, irritating, pungent odor. [Note: A liquid below 14°F. Shipped as a liquefied compressed gas.]
Fe2(SO4)3 – Iron(III) sulfate
Other names: Ferric sulfate, Sulfuric acid, Iron(3+) salt (3:2)