Question

10.0g of iron(ii) ammonium sulphate crystals were made up to 250cm3 of acidified aqueous solution. 25.0cm3 of this solution required 21.25cm3 of

Answer 1

Explanation:

3.00 g of a lawn sand containing an iron (II) salt was shaken with dilute H2SO4. The resulting solution required 25.00 cm3 of 0.0200 mol dm-3 potassium manganate (VII) to oxidise the Fe2+ ions in the solution to Fe3+ ions. Use this to calculate the percentage by mass of Fe2+ ions in this sample of lawn sand.