Question

${{\text{(NiC}{{\text{l}}_{4}})}^{-2}}$ is diamagnetic in nature
(A) True
(B) False

Answer 1

Hint: For this problem, we will first study the diamagnetic nature of the compound and then how it is formed and what is its effect on the neighbouring molecule. Also, the effect of the strong and weak ligand on the central atom.

Complete step by step solution:
-In the given question we have to determine whether the given complex is paramagnetic in nature or diamagnetic.
-Firstly, we should know that diamagnetic molecules are those which consist of all the paired electrons and paramagnetic molecules are those which consist of unpaired electrons in the shell.
-Diamagnetic molecules usually repel the external magnetic field whereas paramagnetic molecules attract the external magnetic field.
-Now, to answer this question we should know that the strong ligand is the ligand which has the ability for pairing the electrons whereas weak ligands cannot help in the pairing of the electrons.
-So, whenever there is the presence of weak ligands such as chlorine, fluorine, nitro group, etc with the central atom the pairing of the electrons doesn't take place.
-Whereas groups such as cyanide, ammonia are strong ligands and induce the pairing of electrons.
-So, as we can see that there is a presence of chlorine ligand with the nickel as a central atom so the pairing of the electrons will not take place.
-Due to which, tetrachloride nickelate (II) ions will be paramagnetic.

Therefore, the given statement is (A) True.

Note: The electronic configuration of nickel is \[(\text{Ar)4}{{\text{s}}^{0}}\text{ 3}{{\text{d}}^{8}}\], in which the two electrons will be unpaired and the chlorine which is weak ligand will make bonds with one 4s and two 4p shells due to which the hybridisation will be \[\text{s}{{\text{p}}^{3}}\].