A quality-control chemist is asked to verify the composition of the pale-green…
CHEMISTRY · Multi-part · CBSE · Chemistry · Acids, Bases and Salts · Acids, Bases and Salts
Problem
A quality-control chemist is asked to verify the composition of the pale-green crystalline solid commonly known as "Mohr’s salt," whose formula is (NH₄)₂Fe(SO₄)₂·6H₂O. A second sample, called "green vitriol," has the formula FeSO₄·7H₂O.
Complete the tasks below, showing all reasoning.
(1) For (NH₄)₂Fe(SO₄)₂·6H₂O, list every unique cation and anion present and state the charge on each.
(2) Write the full systematic name of (NH₄)₂Fe(SO₄)₂·6H₂O.
(3) State the total number of water molecules of crystallization associated with one formula unit of Mohr’s salt and briefly explain how the dot notation conveys this information.
(4) Determine the oxidation state of iron in (i) Mohr’s salt and (ii) green vitriol. Compare the two values and explain, with reference to the formulas, why the oxidation state is the same or different in these compounds.