Chemistry - Salt Analysis Question with Solution | TestHub

The salt X = Sulphide (S²⁻) reacts with sodium nitroprusside in basic medium:

$${\mathrm{S}}^{2-}+[\mathrm{Fe}(\mathrm{CN}{)}_5\mathrm{NO}{]}^{2-}\to [\mathrm{Fe}(\mathrm{CN}{)}_5\mathrm{NOS}{]}^{4-}$$

The purple-colored complex formed is low-spin because the five CN⁻ ligands are strong-field ligands, causing electron pairing in the Fe center.

(A) Denticity of the new ligand is 3 (S²⁻ acts as a monodentate ligand.)

(B) Paramagnetic (Low-spin nitroprusside complex is diamagnetic.)

(C) Low-spin complex Correct

(D) Hybridisation is sp³d² (Nitroprusside is an octahedral inner-orbital (d²sp³) complex, not sp³d².)

Correct Answer: (C) Low-spin complex