The following Latimer diagrams show the standard reduction potentials E^⦵/V for some oxidation states of iron in acid and alkaline solution:

(a) Plot a Frost diagram showing the states of Fe under acid and alkaline conditions.

(b) Calculate the standard potential for the Fe3+/Fe couple in acid
solution.

(c) Explain why the potentials for the Fe(III)/Fe(II) reduction are very different in acid and alkaline conditions, and comment on the fact that FeO₄²⁻ is unknown in acid solution.

(d) FeO₄²⁻ can be prepared by oxidation of Fe(III) by ClO⁻ in alkaline solution. Making use of the standard reduction potentials given below, write an equation for the reaction occurring in this preparation.

Standard potentials E^⦵/V at pH = 14:

Transcribed Image Text:

pH=0 Fe³+- pH = 14 FeO +0.77 →Fe²+ +0.55 -0.44 →FeO₂ → Fe -0.69 →Fe(O)OH- -0.80 →Fe