Q.For the given complex $[Ni(PPh_3)_2Cl_2]$ mention

[Ni(PPh$_3$)$_2$Cl$_2$] is a neutral, four-coordinate Ni(II) complex with two neutral phosphine ligands and two chlorido ligands; its bulky ligands push it toward a tetrahedral, paramagnetic geometry rather than the square-planar arrangement seen with small strong-field ligands.

1. IUPAC Name: Ligands are named in alphabetical order before the metal, with anionic ligands taking the '-ido' ending and the oxidation state of the metal shown in Roman numerals: Dichloridobis(triphenylphosphine)nickel(II) ('chlorido' is cited before 'triphenylphosphine' alphabetically; the multiplying prefix 'bis' is used for the complex ligand name triphenylphosphine because the simple prefix 'di' would be ambiguous).
2. Central metal ion: Since the two Cl ligands are each $-1$ and $PPh_3$ is neutral, and the overall complex is neutral, the metal must be $Ni^{2+}$ — i.e. Nickel(II), $3d^8$ configuration.
3. Ligands: Two triphenylphosphine ($PPh_3$) molecules — neutral, monodentate ligands coordinating through the lone pair on phosphorus — and two chlorido ($Cl^-$) ligands — anionic, monodentate.
4. Coordination number: The metal is bonded to 4 donor atoms in total (2 P + 2 Cl), so the coordination number is 4. …