12 public questions tagged with this topic.
The coordination number is the number of ligand donor atoms directly bonded to the central metal ion. In [Co(NH₃)6]Cl₃, there are 6 NH₃ ligands, each unidentate, so the coordination number is 6.
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Werner's Theory and Definitions - Ligands Coordination Number
Each ethane-1,2-diamine (en) is bidentate (2 donor atoms), and each H₂O is unidentate. In [Ni(en)2(H₂O)2]2+, 2 en (4 atoms) + 2 H₂O = 6.
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Werner's Theory and Definitions - Ligands Coordination Number
[Fe(CO)5] (Fe₀, d8) has 5 CO ligands. EAN = 26 + 2 × 5 = 36, but in organometallic context, 8 valence + 10 from ligands = 18 electrons.
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Werner's Theory and Definitions - Ligands Coordination Number
In [Cr(NH₃)2(en)2]3+, NH₃ is unidentate (2 ligands), and each ethane-1,2-diamine (en) is bidentate (2 donor atoms). Total = 2 + (2 × 2) = 6.
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Werner's Theory and Definitions - Ligands Coordination Number
In [Fe(H₂O)5Cl]SO₄, the coordination sphere [Fe(H₂O)5Cl]+ contains 5 H₂O molecules as ligands.
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Werner's Theory and Definitions - Ligands Coordination Number
In [Cu(en)2]2+, each ethane-1,2-diamine (en) is bidentate, contributing 2 donor atoms. Total = 2 × 2 = 4.
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Werner's Theory and Definitions - Ligands Coordination Number
[Ni(CN)4]2− (Ni₂+, d8) with 4 strong field CN− ligands is square planar and diamagnetic (0 unpaired electrons).
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Werner's Theory and Definitions - Ligands Coordination Number
[Ni(NH₃)4]2+ has 4 NH₃ ligands, giving a coordination number of 4. Others like [Co(NH₃)6]3+ (6) and [Fe(CN)6]4− (6) have higher coordination numbers.
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Werner's Theory and Definitions - Ligands Coordination Number
2 en (4 atoms) + 2 Cl− = 6.
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Werner's Theory and Definitions - Ligands Coordination Number
In [Ni(NH₃)4]2+, Ni is +2 (oxidation state), and the coordination number is 4. None match here, but [Ni(NH₃)4]2+ fits better conceptually.
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Nomenclature of Coordination Compounds
In [Fe(en)(H₂O)3Cl]+, en (bidentate) has 2 N atoms, 3 H₂O have 3 O atoms, and 1 Cl− has 1 Cl atom. Total = 2 + 3 + 1 = 6.
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Isomerism - Geometrical Isomerism in Coordination Compounds
Coordination number = 6 (6 H₂O), counter ions = 3 (3 Cl−). Difference = 6 − 3 = 3.
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Colour and Magnetic Properties and Stability and Importance
