Solveeit Logo
Login

Question

Chemistry Question on Importance and Applications of Coordination Compounds

Which of the following coordination entities should be expected to absorb light of lowest frequency?

A

[Cr(en)3]3+\left[ Cr ( en )_{3}\right]^{3+}

B

[CrCl6]3−\left[ CrCl _{6}\right]^{3-}

C

[Cr(NH3)6]3+\left[ Cr \left( NH _{3}\right)_{6}\right]^{3+}

D

[Cr(CN)6]3−\left[ Cr ( CN )_{6}\right]^{3-}

Answer

[CrCl6]3−\left[ CrCl _{6}\right]^{3-}

Explanation

Solution

The coordination entity, for which crystal field splitting is smaller, absorbs light of lowest frequency. Weaker the ligand field strength, smaller will be the crystal field splitting. The order of field strength of various ligands is as CN>en>NH3>ClCN > en > NH _{3}> Cl Hence, [CrCl6]3−\left[ CrCl _{6}\right]^{3-} due to the presence of Cl−Cl ^{-} ligand absorbs light of lowest frequency.