Physical Chemistry> [Fe(CN)6]4– and [Fe(H2O)6]2+ are of diffe...

[Fe(CN)6]4– and [Fe(H2O)6]2+ are of different colours in dilute solutions. Why?

rishav kumar , 11 Years ago

Grade 9

2 Answers

Sunil Kumar FP

Last Activity: 11 Years ago

The colour of a particular coordination compound depends on the magnitude of the crystal-field splitting energy, Δ. This CFSE in turn depends on the nature of the ligand. In case of [Fe(CN)6]4− and [Fe(H2O)6]2+, the colour differs because there is a difference in the CFSE. Now, CN− is a strong field ligand having a higher CFSE value as compared to the CFSE value of water. This means that the absorption of energy for the intra d-d transition also differs. Hence, the transmitted colour also differs.

kunal kashyap

Last Activity: 8 Years ago

The colour of a particular coordination compound depends on the magnitude of the crystal-field splitting energy, Δ. This CFSE in turn depends on the nature of the ligand. In case of [Fe(CN)6]4- and [Fe(H2O)6]2+, the colour differs because there is a difference in the CFSE. Now, CN- is a strong field ligand having a higher CFSE value as compared to the CFSE value of water. This means that the absorption of energy for the intra d-d transition also differs. Hence, the transmitted colour also differs.