Explore Werner's theory of coordination compounds, including key definitions, ligands, and coordination numbers. Includes practice questions and explanations to help with chemistry exams.
[Co(NH₃)6]Cl₃ dissociates into [Co(NH₃)6]3+ and 3 Cl−, producing 4 ions total, but the sphere itself is associated with 3 counter ions.
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Werner's Theory and Definitions - Ligands Coordination Number
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
In [Co(NH₃)4Cl₂]Cl, the Cl− outside the coordination sphere is ionizable. The 2 Cl− inside are ligands and not ionizable. Thus, 1 Cl− ionizes.
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
In [Fe(CN)5NO]2−, NO is NO+ (+1), 5 CN− = −5. Overall charge is −2. Thus, x + (−5) + 1 = −2, x = +2, but the sphere’s charge is −2.
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Werner's Theory and Definitions - Ligands Coordination Number
In [Fe(NH₃)5Cl]Cl₂, the 2 Cl− ions outside the coordination sphere are ionizable and form AgCl, while the inner Cl is a ligand. Thus, 2 moles precipitate.
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Werner's Theory and Definitions - Ligands Coordination Number
Fe₂+ (d6), weak field H₂O, octahedral, high spin: t2g4 eg2. Ratio = 2 : 4 = 1 : 2.
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Werner's Theory and Definitions - Ligands Coordination Number
Primary valence is the oxidation state. In [CoCl₂(NH₃)4]Cl, the complex [CoCl₂(NH₃)4]+ has a +1 charge (balanced by 1 Cl−). NH₃ is neutral, Cl− is −1. Thus, Co’s oxidation state = +3 (since +3 + 2(−1) = +1).
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
Ionization isomerism involves exchange of ligands and counter ions. [Co(NH₃)5SO₄]Br and [Co(NH₃)5Br]SO₄ differ in which ion is inside/outside the coordination sphere.
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 [Ni(NH₃)4Cl₂]Cl₂, the 2 Cl− ions outside the coordination sphere are ionizable and precipitate as AgCl, while the 2 inside are ligands. Thus, 2 moles form.
Ref: NCERT Class 12 Chemistry > Chapter 5: Coordination Compounds > Topic: Werner's Theory and Definitions - Ligands Coordination Number
