Q.

The correct sequence of ligands in the order of decreasing field strength is :                      [2024]

1 S2->OH->EDTA4->CO  
2 OH->F->NH3>CN-  
3 CO>H2O>F->S2-  
4 NCS->EDTA4->CN->CO  

Ans.

(3)

Ligands can be arranged in a series in the order of increasing field strength as given below:

I-<Br-<SCN-<Cl-<S2-<F-<OH-<C2O42-<H2O<NCS-<edta4-<NH3<en<CN-<CO