What is spectrochemical series? Explain the difference between a weak - field ligand and a strong - field ligand.

Explanation

Difference between weak - field and strong - field ligand : The ligands which create large splitting in octahedral or tertrahedral crystal field and consequently the value of CFSE increases, are called strong field ligands. The ligands which create very small spillitting in the same crystal field (octahedral or tetrahedral) resulting small value of CFSE, are called weak field ligands.