BITSAT 2023 Shift 1 Paper

Ligands can be arranged in a series in the orders of increasing field strength as given below:
Weak field ligands :
I−<Br−<S2−<SCN‌<Cl−<N3−,F−
‌<‌Urea, ‌OH−<‌oxalate ‌
Strong field ligands
O−−<H2O<NCS−<EDTA<Py,NH3<
‌ en ‌=SO3−<‌bipy, ‌Phen<NO2−<CH3−
<C6H5−<CN−<CO
Such a series is termed as spectrochemical series. It is an experimentally determined series based on the absorption of light by complexes with different ligands.