Colour of compounds occurs due to phenomenon of polarisation, charge transfer, d-d transition and H.O.M.O.L.U.M.O transition. Most of the transition metal transition metal complex compound are coloured either due to d-d electrons transition or charge transfer and ionic compounds are coloured due to polarisation of anion. Q. Which of the following is correct about `KFe^(II)[underset(III)(Fe)(CN_(6))] and KFe^(III)[underset(II)(Fe)(CN_(6))]` complex compounds?

Options

A. Both are blue coloured compounds because colour arises due to d-d electrons transition in Fe cation present outside the complex ion.
B. Both are blue coloured compounds because colour arises due to transfer of electron between `Fe^(II) and Fe^(III)` cation
C. Both are blue coloured compounds because in complexes `Fe^(II)` cation shows same d-d transition bond
D. Complex (I) has blue colour becouse (II) has brown colour

Answer

B