Fe (OH) 3+NaOH => FeCl3+K4[Fe (CN) 6] => CuSO4+K4[Fe (CN) 6] => KMnO4+H2SO4+Na2SO3

Fe (OH) 3+NaOH -> (сплавление) NaFeO2+2H2OFeCl3+K4[Fe (CN) 6] -> 3KCl+KFe[Fe (CN) 6]2CuSO4+K4[Fe (CN) 6]=Cu2[Fe (CN) 6]+2K2SO42KMnO4+3H2SO4+5Na2SO3=2MnSO4+K2SO4+5Na2SO4+H2OMn (+7)+5e -> Mn (+2) | 2S (+4) -2e -> S (+6) | 52Mn (+7)+5S (+4) -> 2Mn (+2)+5S (+6)