Question

Which of the following statements is incorrect?
A.In ${K_3}\left[ {Fe{{\left( {CN} \right)}_6}} \right]$ , the ligand has satisfied only the secondary valency of ferric ion
B.In ${K_3}\left[ {Fe{{\left( {CN} \right)}_6}} \right]$ , the ligand has satisfied both primary and secondary valencies of ferric ion
C.In ${K_4}\left[ {Fe{{\left( {CN} \right)}_6}} \right]$ , the ligand has satisfied both primary and secondary valencies of ferrous ion
D.In $\left[ {Cu{{\left( {N{H_3}} \right)}_4}} \right]S{O_4}$ , the ligand has satisfied only the secondary valency of copper

Answer 1

Hint: We have to know that, valency is the capacity of a particle to acquire or lose electrons to accomplish the respectable gas arrangement. It alludes to the capacity of a component to consolidate with other components. It is obtained by deciding the quantity of electrons in the furthest shell of every particle of a component.

Complete answer:
As we probably are aware, the primary and secondary valencies are the proposes of Werner's hypothesis. As indicated by Werner's hypothesis, the focal metal in coordination intensifies show two kinds of valencies. They are primary valency and secondary valency.
We need to realize that the primary valency in coordination compounds is the quantity of negative particles which are comparable to the charge on the metal particle.
We need to realize that, the secondary valence is the quantity of particles of atoms that are facilitated to the metal particle or it is the quantity of ligands appended or composed to metal particles.
As per the above details,
For option (a),
In ${K_3}\left[ {Fe{{\left( {CN} \right)}_6}} \right]$ , the ligand has satisfied only the secondary valency of ferric ion.
It does not obey the above rule. The given statement is incorrect. Therefore, the option (A) is correct.
Remaining options obey the above rule. So, the remaining statements are correct. Therefore, the remaining options are incorrect.

Note:
You need to know a careful comprehension about essential and optional valency. Recall that essential valency is ionisable and the auxiliary valencies are non-ionisable in the complex. The focal particle is encircled by ligands and is projected in space giving explicit shape to the complex.