Axit H2 SO4 đặc ,nóng tác dụng với Fe2 O3 tạo ra sản phẩm là . A. Fe2(SO4)3 và H2O
B. SO2 vàFe2(SO4)3
C. Fe2(SO4)3,SO2và H2O
D. Fe2(SO4)3

The content of manganese (mn) in steel was determined spectrophotometrically and with the use of the standard addition method. an unknown sample of mn from a digested steel sample gave an absorbance of 0.185 when analyzed spectrophotometrically. when 5.00 ml of solution containing 95.5 ppm mn was added to 50.0 ml of the unknown steel solution (digested sample), the absorbance was 0.248. calculate the concentration, in parts-per-million (ppm), of mn in the digested steel sample solution.