Question

70.
Average oxidation number of iron in Fe4[Fe(CN)6]3 is
(A) +2
(B) 17/7
(C) 18/7
(D) +3​

Answer 1

Answer:

+2 is the the answer in the question

Answer 2

Oxidation state of outer Fe

The dissociation of Fe4[Fe(CN)6]3 can be written as

Fe4[Fe(CN)6]3 → 4 Fe3+ + 3 [Fe(CN)6]4-

Hence, the oxidation state of outer Fe is +3

Oxidation State of inner Fe

Let the oxidation number of Fe be X

Here oxidation number on CN = -1

For [Fe(CN)6]4-

X × 6 (-1) = -4

∴ X = +2, the oxidation state of inner Fe.