What is the total number of donor atoms in the ligands of [Ni(en)(NH₃)2(H₂O)]2+?
en (bidentate) has 2 donor atoms, 2 NH₃ (unidentate) have 2, and 1 H₂O (unidentate) has 1. Total = 2 + 2 + 1 = 5.
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Isomerism - Geometrical Isomerism in Coordination Compounds