JEE Advanced Chemistry question

Why does aqueous Fe(III) ion develop an intense red colour when it reacts with the ion, while Fe(II) ion does not?

(A)Fe(III) ion forms a charge transfer complex with ionsCorrect
(B)Fe(III) is reduced to Fe(I) which is deep red in colour
(C) ion is oxidized to which forms a red coloured complex with Fe(III) ion
(D) does not form any complex with Fe(III) ion

Answer: (A)

Solution

Fe^{3+} + SCN^- \rightarrow [Fe(SCN)]^{2+} forms directly, with the intense blood-red colour arising from a ligand-to-metal charge-transfer transition —

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Question ID VK-159901