Help Please! Due tonight When 1.1323 g of an organic iron compound containing Fe, C, H, and O was burned in O2, 2.1179 g of CO2 and 0.60611 g of H2O were produced. In a separate experiment to determine the mass percent of iron, 0.2686 g of the compound yielded 0.06069 g of Fe2O3. What is the empirical formula of the compound?

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.