What is the primary valence of Ni in [Ni(en)2Cl₂]?
In [Ni(en)2Cl₂], en is neutral, 2 Cl− balance Ni, making Ni +2. Primary valence is the oxidation state, so 2.
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Isomerism - Optical Isomerism and Linkage Ionisation Solvate