FexOy + H2SO4(đn) -to-> Fe2(SO4)3 + SO2 + H2O
2 \(|^{ }_{ }\) xFe(+2y/x) --> xFe3+ + (3x - 2y )e
3x - 2y \(|\)S+6 + 2e --> S+4
2FexOy + (6x - 2y ) H2SSO4(đn) -to-> xFe2(SO4)3 + (3x - 2y ) SO2 + (6x - 2y ) H2O
2FexOy + (6x-2y)H2SO4 (đ) \(\underrightarrow{t^o}\) xFe2(SO4)3 + (3x-2y)SO2\(\uparrow\) + (6x-2y)H2O