13.2 g of iron (III) alum were dissolved in water and reduced to an iron(II) ion…
CHEMISTRY · Subjective · A Level · Chemistry · Oxidation, reduction and redox reactions · Oxidation, reduction and redox reactions
Problem
13.2 g of iron (III) alum were dissolved in water and reduced to an iron(II) ion solution by zinc and dilute sulphuric acid. The mixture was filtered and the filtrate and washings made up to 500 cm³ in a standard volumetric flask. 20.0 cm³ of this solution required 26.5 cm³ of 0.01 mol dm⁻³ KMnO₄ for oxidation. Calculate the percentage by mass of iron in iron alum.