Question

In Feo solid, some Fe+2 ions are missing, but the charge is Balanced by the presence of Fe+3 ions. 1)if Fe+2 ions missing are 15, how many Fe+3 ions balance the charge .2) what type of defect does this lead to . 3) if for 100 O-2 ions the number is Fe+2 and Fe+3 are 85 and 10 respectively , what is the composition of non stoichiometric FeO solid formed?​

Answer 1

The favorable reaction is the oxidation of iodide ion to iodine.

I

−

will be oxidised to I

2

2e

−

+Fe

+3

⟶Fe

2+

; E=0.77V

2I

−

⟶I

2

+2e

−

; E=0.536V

___________________________________________

2Fe

+3

+2I

−

⟶2Fe

+2

+I

2

; E=E

ox

+E

red

=0.77−0.536

=0.164V