Question #44904

The question tests the fundamental postulates of Werner's Coordination Theory while introducing a complex polydentate ligand (TEPA) to create multiple cognitive traps.

Trap 1: Students often confuse the prefix 'tetra' in tetraethylenepentamine, mistakenly assuming it is a tetradentate ligand (like trien), which leads to an incorrect coordination sphere $[Pt(\text{TEPA})Cl_2]Cl_2$ and $z=2$ (Option B).

Trap 2: A common misconception is equating Werner's primary valency directly to the number of ionizable counter-ions precipitated by $AgNO_3$, leading to $p=z=3$ (Option C).

Primary valency is strictly the oxidation state.

Trap 3: Failing to deduce the coordination number from the crystal field electronic configuration ($t_{2g}^6 e_g^0$ dictates an octahedral $CN=6$ geometry for $5d$ metals).